Non functional Java styling changes (#10808)

* Replace explicit <Type> with <>

* Remove redundant toString() calls on String

* Use StandardCharsets.UTF_8 instead "UTF-8" string

* Simpler annotation format and redundant this

* Dont concat on empty String, use String.valueOf()

* Dont run equals on empty String

* Use string.anyMatch instead counting

* Collection add all instead iterating and adding

* Replace string contact with append chain in stringBuilders

modules/openapi-generator/src/main/java/org/openapitools/codegen/CodegenConfigLoader.java

@@ -45,7 +45,7 @@ public class CodegenConfigLoader {
         try {
             return (CodegenConfig) Class.forName(name).getDeclaredConstructor().newInstance();
         } catch (Exception e) {
-            throw new GeneratorNotFoundException("Can't load config class with name '".concat(name) + "'\nAvailable:\n" + availableConfigs.toString(), e);
+            throw new GeneratorNotFoundException("Can't load config class with name '".concat(name) + "'\nAvailable:\n" + availableConfigs, e);
         }
     }
 

modules/openapi-generator/src/main/java/org/openapitools/codegen/CodegenModel.java

@@ -45,9 +45,9 @@ public class CodegenModel implements IJsonSchemaValidationProperties {
     public List<CodegenModel> children;
 
     // anyOf, oneOf, allOf
-    public Set<String> anyOf = new TreeSet<String>();
+    public Set<String> anyOf = new TreeSet<>();
-    public Set<String> oneOf = new TreeSet<String>();
+    public Set<String> oneOf = new TreeSet<>();
-    public Set<String> allOf = new TreeSet<String>();
+    public Set<String> allOf = new TreeSet<>();
 
     // The schema name as written in the OpenAPI document.
     public String name;
@@ -66,20 +66,20 @@ public class CodegenModel implements IJsonSchemaValidationProperties {
     public boolean isAlias; // Is this effectively an alias of another simple type
     public boolean isString, isInteger, isLong, isNumber, isNumeric, isFloat, isDouble, isDate, isDateTime, isShort, isUnboundedInteger, isBoolean;
     private boolean additionalPropertiesIsAnyType;
-    public List<CodegenProperty> vars = new ArrayList<CodegenProperty>(); // all properties (without parent's properties)
+    public List<CodegenProperty> vars = new ArrayList<>(); // all properties (without parent's properties)
-    public List<CodegenProperty> allVars = new ArrayList<CodegenProperty>(); // all properties (with parent's properties)
+    public List<CodegenProperty> allVars = new ArrayList<>(); // all properties (with parent's properties)
-    public List<CodegenProperty> requiredVars = new ArrayList<CodegenProperty>(); // a list of required properties
+    public List<CodegenProperty> requiredVars = new ArrayList<>(); // a list of required properties
-    public List<CodegenProperty> optionalVars = new ArrayList<CodegenProperty>(); // a list of optional properties
+    public List<CodegenProperty> optionalVars = new ArrayList<>(); // a list of optional properties
-    public List<CodegenProperty> readOnlyVars = new ArrayList<CodegenProperty>(); // a list of read-only properties
+    public List<CodegenProperty> readOnlyVars = new ArrayList<>(); // a list of read-only properties
-    public List<CodegenProperty> readWriteVars = new ArrayList<CodegenProperty>(); // a list of properties for read, write
+    public List<CodegenProperty> readWriteVars = new ArrayList<>(); // a list of properties for read, write
-    public List<CodegenProperty> parentVars = new ArrayList<CodegenProperty>();
+    public List<CodegenProperty> parentVars = new ArrayList<>();
     public Map<String, Object> allowableValues;
 
     // Sorted sets of required parameters.
-    public Set<String> mandatory = new TreeSet<String>(); // without parent's required properties
+    public Set<String> mandatory = new TreeSet<>(); // without parent's required properties
-    public Set<String> allMandatory = new TreeSet<String>(); // with parent's required properties
+    public Set<String> allMandatory = new TreeSet<>(); // with parent's required properties
 
-    public Set<String> imports = new TreeSet<String>();
+    public Set<String> imports = new TreeSet<>();
     public boolean hasVars, emptyVars, hasMoreModels, hasEnums, isEnum, hasValidation;
     /**
      * Indicates the OAS schema specifies "nullable: true".
@@ -104,7 +104,7 @@ public class CodegenModel implements IJsonSchemaValidationProperties {
     public boolean hasOnlyReadOnly = true; // true if all properties are read-only
     public ExternalDocumentation externalDocumentation;
 
-    public Map<String, Object> vendorExtensions = new HashMap<String, Object>();
+    public Map<String, Object> vendorExtensions = new HashMap<>();
     private CodegenComposedSchemas composedSchemas;
     private boolean hasMultipleTypes = false;
 
@@ -320,7 +320,7 @@ public class CodegenModel implements IJsonSchemaValidationProperties {
 
     public void setDiscriminator(CodegenDiscriminator discriminator) {
         this.discriminator = discriminator;
-        if (discriminator instanceof CodegenDiscriminator && !discriminator.getMappedModels().isEmpty()) {
+        if (discriminator != null && !discriminator.getMappedModels().isEmpty()) {
             this.hasDiscriminatorWithNonEmptyMapping = true;
         }
     }
@@ -1067,13 +1067,13 @@ public class CodegenModel implements IJsonSchemaValidationProperties {
 
     private List<CodegenProperty> removeDuplicatedProperty(List<CodegenProperty> vars) {
         // clone the list first
-        List<CodegenProperty> newList = new ArrayList<CodegenProperty>();
+        List<CodegenProperty> newList = new ArrayList<>();
         for (CodegenProperty cp : vars) {
             newList.add(cp.clone());
         }
 
-        Set<String> propertyNames = new TreeSet<String>();
+        Set<String> propertyNames = new TreeSet<>();
-        Set<String> duplicatedNames = new TreeSet<String>();
+        Set<String> duplicatedNames = new TreeSet<>();
 
         ListIterator<CodegenProperty> iterator = newList.listIterator();
         while (iterator.hasNext()) {

modules/openapi-generator/src/main/java/org/openapitools/codegen/DefaultCodegen.java

@@ -147,8 +147,8 @@ public class DefaultCodegen implements CodegenConfig {
     protected Map<String, String> typeMapping;
     protected Map<String, String> instantiationTypes;
     protected Set<String> reservedWords;
-    protected Set<String> languageSpecificPrimitives = new HashSet<String>();
+    protected Set<String> languageSpecificPrimitives = new HashSet<>();
-    protected Map<String, String> importMapping = new HashMap<String, String>();
+    protected Map<String, String> importMapping = new HashMap<>();
     protected String modelPackage = "", apiPackage = "", fileSuffix;
     protected String modelNamePrefix = "", modelNameSuffix = "";
     protected String apiNamePrefix = "", apiNameSuffix = "Api";
@@ -159,25 +159,25 @@ public class DefaultCodegen implements CodegenConfig {
     apiTemplateFiles are for API outputs only (controllers/handlers).
     API templates may be written multiple times; APIs are grouped by tag and the file is written once per tag group.
     */
-    protected Map<String, String> apiTemplateFiles = new HashMap<String, String>();
+    protected Map<String, String> apiTemplateFiles = new HashMap<>();
-    protected Map<String, String> modelTemplateFiles = new HashMap<String, String>();
+    protected Map<String, String> modelTemplateFiles = new HashMap<>();
-    protected Map<String, String> apiTestTemplateFiles = new HashMap<String, String>();
+    protected Map<String, String> apiTestTemplateFiles = new HashMap<>();
-    protected Map<String, String> modelTestTemplateFiles = new HashMap<String, String>();
+    protected Map<String, String> modelTestTemplateFiles = new HashMap<>();
-    protected Map<String, String> apiDocTemplateFiles = new HashMap<String, String>();
+    protected Map<String, String> apiDocTemplateFiles = new HashMap<>();
-    protected Map<String, String> modelDocTemplateFiles = new HashMap<String, String>();
+    protected Map<String, String> modelDocTemplateFiles = new HashMap<>();
-    protected Map<String, String> reservedWordsMappings = new HashMap<String, String>();
+    protected Map<String, String> reservedWordsMappings = new HashMap<>();
     protected String templateDir;
     protected String embeddedTemplateDir;
     protected Map<String, Object> additionalProperties = new HashMap<>();
-    protected Map<String, String> serverVariables = new HashMap<String, String>();
+    protected Map<String, String> serverVariables = new HashMap<>();
-    protected Map<String, Object> vendorExtensions = new HashMap<String, Object>();
+    protected Map<String, Object> vendorExtensions = new HashMap<>();
     /*
     Supporting files are those which aren't models, APIs, or docs.
     These get a different map of data bound to the templates. Supporting files are written once.
     See also 'apiTemplateFiles'.
     */
-    protected List<SupportingFile> supportingFiles = new ArrayList<SupportingFile>();
+    protected List<SupportingFile> supportingFiles = new ArrayList<>();
-    protected List<CliOption> cliOptions = new ArrayList<CliOption>();
+    protected List<CliOption> cliOptions = new ArrayList<>();
     protected boolean skipOverwrite;
     protected boolean removeOperationIdPrefix;
     protected String removeOperationIdPrefixDelimiter = "_";
@@ -210,7 +210,7 @@ public class DefaultCodegen implements CodegenConfig {
      */
     protected boolean supportsAdditionalPropertiesWithComposedSchema;
     protected boolean supportsMixins;
-    protected Map<String, String> supportedLibraries = new LinkedHashMap<String, String>();
+    protected Map<String, String> supportedLibraries = new LinkedHashMap<>();
     protected String library;
     protected Boolean sortParamsByRequiredFlag = true;
     protected Boolean sortModelPropertiesByRequiredFlag = false;
@@ -222,7 +222,7 @@ public class DefaultCodegen implements CodegenConfig {
     // How to encode special characters like $
     // They are translated to words like "Dollar" and prefixed with '
     // Then translated back during JSON encoding and decoding
-    protected Map<String, String> specialCharReplacements = new HashMap<String, String>();
+    protected Map<String, String> specialCharReplacements = new HashMap<>();
     // When a model is an alias for a simple type
     protected Map<String, String> typeAliases = null;
     protected Boolean prependFormOrBodyParameters = false;
@@ -236,7 +236,7 @@ public class DefaultCodegen implements CodegenConfig {
     protected boolean useOneOfInterfaces = false;
     // whether or not the oneOf imports machinery should add oneOf interfaces as imports in implementing classes
     protected boolean addOneOfInterfaceImports = false;
-    protected List<CodegenModel> addOneOfInterfaces = new ArrayList<CodegenModel>();
+    protected List<CodegenModel> addOneOfInterfaces = new ArrayList<>();
 
     // flag to indicate whether to only update files whose contents have changed
     protected boolean enableMinimalUpdate = false;
@@ -260,7 +260,7 @@ public class DefaultCodegen implements CodegenConfig {
     private Map<String, Schema> modelNameToSchemaCache;
 
     // A cache to efficiently lookup schema `toModelName()` based on the schema Key
-    private Map<String, String> schemaKeyToModelNameCache = new HashMap<>();
+    private final Map<String, String> schemaKeyToModelNameCache = new HashMap<>();
 
     @Override
     public List<CliOption> cliOptions() {
@@ -440,7 +440,7 @@ public class DefaultCodegen implements CodegenConfig {
 
             // Gather data from all the models that contain oneOf into OneOfImplementorAdditionalData classes
             // (see docstring of that class to find out what information is gathered and why)
-            Map<String, OneOfImplementorAdditionalData> additionalDataMap = new HashMap<String, OneOfImplementorAdditionalData>();
+            Map<String, OneOfImplementorAdditionalData> additionalDataMap = new HashMap<>();
             for (Map.Entry<String, Object> modelsEntry : objs.entrySet()) {
                 Map<String, Object> modelsAttrs = (Map<String, Object>) modelsEntry.getValue();
                 List<Object> models = (List<Object>) modelsAttrs.get("models");
@@ -503,7 +503,7 @@ public class DefaultCodegen implements CodegenConfig {
      * @return map of all models indexed by names
      */
     public Map<String, CodegenModel> getAllModels(Map<String, Object> objs) {
-        Map<String, CodegenModel> allModels = new HashMap<String, CodegenModel>();
+        Map<String, CodegenModel> allModels = new HashMap<>();
         for (Entry<String, Object> entry : objs.entrySet()) {
             String modelName = toModelName(entry.getKey());
             Map<String, Object> inner = (Map<String, Object>) entry.getValue();
@@ -823,9 +823,9 @@ public class DefaultCodegen implements CodegenConfig {
     public void preprocessOpenAPI(OpenAPI openAPI) {
         if (useOneOfInterfaces) {
             // we process the openapi schema here to find oneOf schemas and create interface models for them
-            Map<String, Schema> schemas = new HashMap<String, Schema>(openAPI.getComponents().getSchemas());
+            Map<String, Schema> schemas = new HashMap<>(openAPI.getComponents().getSchemas());
             if (schemas == null) {
-                schemas = new HashMap<String, Schema>();
+                schemas = new HashMap<>();
             }
             Map<String, PathItem> pathItems = openAPI.getPaths();
 
@@ -858,12 +858,12 @@ public class DefaultCodegen implements CodegenConfig {
             }
 
             // also add all properties of all schemas to be checked for oneOf
-            Map<String, Schema> propertySchemas = new HashMap<String, Schema>();
+            Map<String, Schema> propertySchemas = new HashMap<>();
             for (Map.Entry<String, Schema> e : schemas.entrySet()) {
                 Schema s = e.getValue();
                 Map<String, Schema> props = s.getProperties();
                 if (props == null) {
-                    props = new HashMap<String, Schema>();
+                    props = new HashMap<>();
                 }
                 for (Map.Entry<String, Schema> p : props.entrySet()) {
                     propertySchemas.put(e.getKey() + "/" + p.getKey(), p.getValue());
@@ -1431,7 +1431,7 @@ public class DefaultCodegen implements CodegenConfig {
     public String toVarName(final String name) {
         if (reservedWords.contains(name)) {
             return escapeReservedWord(name);
-        } else if (name.chars().anyMatch(character -> specialCharReplacements.containsKey("" + ((char) character)))) {
+        } else if (name.chars().anyMatch(character -> specialCharReplacements.containsKey(String.valueOf((char) character)))) {
             return escape(name, specialCharReplacements, null, null);
         }
         return name;
@@ -1449,7 +1449,7 @@ public class DefaultCodegen implements CodegenConfig {
         name = removeNonNameElementToCamelCase(name); // FIXME: a parameter should not be assigned. Also declare the methods parameters as 'final'.
         if (reservedWords.contains(name)) {
             return escapeReservedWord(name);
-        } else if (name.chars().anyMatch(character -> specialCharReplacements.containsKey("" + ((char) character)))) {
+        } else if (name.chars().anyMatch(character -> specialCharReplacements.containsKey(String.valueOf((char) character)))) {
             return escape(name, specialCharReplacements, null, null);
         }
         return name;
@@ -1547,7 +1547,7 @@ public class DefaultCodegen implements CodegenConfig {
                 .generationMessage(String.format(Locale.ROOT, "OpenAPI Generator: %s (%s)", getName(), codegenType.toValue()))
                 .build();
 
-        defaultIncludes = new HashSet<String>(
+        defaultIncludes = new HashSet<>(
                 Arrays.asList("double",
                         "int",
                         "long",
@@ -1564,7 +1564,7 @@ public class DefaultCodegen implements CodegenConfig {
                         "Float")
         );
 
-        typeMapping = new HashMap<String, String>();
+        typeMapping = new HashMap<>();
         typeMapping.put("array", "List");
         typeMapping.put("set", "Set");
         typeMapping.put("map", "Map");
@@ -1591,9 +1591,9 @@ public class DefaultCodegen implements CodegenConfig {
         typeMapping.put("URI", "URI");
         typeMapping.put("AnyType", "oas_any_type_not_mapped");
 
-        instantiationTypes = new HashMap<String, String>();
+        instantiationTypes = new HashMap<>();
 
-        reservedWords = new HashSet<String>();
+        reservedWords = new HashSet<>();
 
         cliOptions.add(CliOption.newBoolean(CodegenConstants.SORT_PARAMS_BY_REQUIRED_FLAG,
                 CodegenConstants.SORT_PARAMS_BY_REQUIRED_FLAG_DESC).defaultValue(Boolean.TRUE.toString()));
@@ -1748,7 +1748,7 @@ public class DefaultCodegen implements CodegenConfig {
                     if (!param.getRequired()) {
                         paramPart.append("]");
                     }
-                    sb.append(paramPart.toString());
+                    sb.append(paramPart);
                 }
             }
         }
@@ -2382,14 +2382,14 @@ public class DefaultCodegen implements CodegenConfig {
         }
     }
 
-    Map<NamedSchema, CodegenProperty> schemaCodegenPropertyCache = new HashMap<NamedSchema, CodegenProperty>();
+    Map<NamedSchema, CodegenProperty> schemaCodegenPropertyCache = new HashMap<>();
 
     protected void updateModelForComposedSchema(CodegenModel m, Schema schema, Map<String, Schema> allDefinitions) {
         final ComposedSchema composed = (ComposedSchema) schema;
-        Map<String, Schema> properties = new LinkedHashMap<String, Schema>();
+        Map<String, Schema> properties = new LinkedHashMap<>();
-        List<String> required = new ArrayList<String>();
+        List<String> required = new ArrayList<>();
-        Map<String, Schema> allProperties = new LinkedHashMap<String, Schema>();
+        Map<String, Schema> allProperties = new LinkedHashMap<>();
-        List<String> allRequired = new ArrayList<String>();
+        List<String> allRequired = new ArrayList<>();
 
         // if schema has properties outside of allOf/oneOf/anyOf also add them to m
         if (composed.getProperties() != null && !composed.getProperties().isEmpty()) {
@@ -2407,7 +2407,7 @@ public class DefaultCodegen implements CodegenConfig {
 
         // TODO revise the logic below to set discriminator, xml attributes
         if (supportsInheritance || supportsMixins) {
-            m.allVars = new ArrayList<CodegenProperty>();
+            m.allVars = new ArrayList<>();
             if (composed.getAllOf() != null) {
                 int modelImplCnt = 0; // only one inline object allowed in a ComposedModel
                 int modelDiscriminators = 0; // only one discriminator allowed in a ComposedModel
@@ -2443,7 +2443,7 @@ public class DefaultCodegen implements CodegenConfig {
         if (!interfaces.isEmpty()) {
             // m.interfaces is for backward compatibility
             if (m.interfaces == null)
-                m.interfaces = new ArrayList<String>();
+                m.interfaces = new ArrayList<>();
 
             for (Schema interfaceSchema : interfaces) {
                 interfaceSchema = unaliasSchema(interfaceSchema, importMapping);
@@ -2521,7 +2521,7 @@ public class DefaultCodegen implements CodegenConfig {
             m.parent = toModelName(parentName);
 
             if (supportsMultipleInheritance) {
-                m.allParents = new ArrayList<String>();
+                m.allParents = new ArrayList<>();
                 for (String pname : allParents) {
                     String pModelName = toModelName(pname);
                     m.allParents.add(pModelName);
@@ -2673,7 +2673,7 @@ public class DefaultCodegen implements CodegenConfig {
             // TODO remove the anyType check here in the future ANyType models can have enums defined
             m.isEnum = true;
             // comment out below as allowableValues is not set in post processing model enum
-            m.allowableValues = new HashMap<String, Object>();
+            m.allowableValues = new HashMap<>();
             m.allowableValues.put("values", schema.getEnum());
         }
         if (!ModelUtils.isArraySchema(schema)) {
@@ -2742,7 +2742,7 @@ public class DefaultCodegen implements CodegenConfig {
         // set isDiscriminator on the discriminator property
         if (m.discriminator != null) {
             String discPropName = m.discriminator.getPropertyBaseName();
-            List<List<CodegenProperty>> listOLists = new ArrayList<List<CodegenProperty>>();
+            List<List<CodegenProperty>> listOLists = new ArrayList<>();
             listOLists.add(m.requiredVars);
             listOLists.add(m.vars);
             listOLists.add(m.allVars);
@@ -3461,13 +3461,13 @@ public class DefaultCodegen implements CodegenConfig {
         //Inline enum case:
         if (p.getEnum() != null && !p.getEnum().isEmpty()) {
             List<Object> _enum = p.getEnum();
-            property._enum = new ArrayList<String>();
+            property._enum = new ArrayList<>();
             for (Object i : _enum) {
                 property._enum.add(String.valueOf(i));
             }
             property.isEnum = true;
 
-            Map<String, Object> allowableValues = new HashMap<String, Object>();
+            Map<String, Object> allowableValues = new HashMap<>();
             allowableValues.put("values", _enum);
             if (allowableValues.size() > 0) {
                 property.allowableValues = allowableValues;
@@ -3480,7 +3480,7 @@ public class DefaultCodegen implements CodegenConfig {
         if (referencedSchema.getEnum() != null && !referencedSchema.getEnum().isEmpty()) {
             List<Object> _enum = referencedSchema.getEnum();
 
-            Map<String, Object> allowableValues = new HashMap<String, Object>();
+            Map<String, Object> allowableValues = new HashMap<>();
             allowableValues.put("values", _enum);
             if (allowableValues.size() > 0) {
                 property.allowableValues = allowableValues;
@@ -3783,7 +3783,7 @@ public class DefaultCodegen implements CodegenConfig {
                                         Map<String, Schema> schemas,
                                         CodegenOperation op,
                                         ApiResponse methodResponse) {
-        handleMethodResponse(operation, schemas, op, methodResponse, Collections.<String, String>emptyMap());
+        handleMethodResponse(operation, schemas, op, methodResponse, Collections.emptyMap());
     }
 
     /**
@@ -3888,7 +3888,7 @@ public class DefaultCodegen implements CodegenConfig {
 
         Map<String, Schema> schemas = ModelUtils.getSchemas(this.openAPI);
         CodegenOperation op = CodegenModelFactory.newInstance(CodegenModelType.OPERATION);
-        Set<String> imports = new HashSet<String>();
+        Set<String> imports = new HashSet<>();
         if (operation.getExtensions() != null && !operation.getExtensions().isEmpty()) {
             op.vendorExtensions.putAll(operation.getExtensions());
 
@@ -3986,15 +3986,15 @@ public class DefaultCodegen implements CodegenConfig {
         }
 
         List<Parameter> parameters = operation.getParameters();
-        List<CodegenParameter> allParams = new ArrayList<CodegenParameter>();
+        List<CodegenParameter> allParams = new ArrayList<>();
-        List<CodegenParameter> bodyParams = new ArrayList<CodegenParameter>();
+        List<CodegenParameter> bodyParams = new ArrayList<>();
-        List<CodegenParameter> pathParams = new ArrayList<CodegenParameter>();
+        List<CodegenParameter> pathParams = new ArrayList<>();
-        List<CodegenParameter> queryParams = new ArrayList<CodegenParameter>();
+        List<CodegenParameter> queryParams = new ArrayList<>();
-        List<CodegenParameter> headerParams = new ArrayList<CodegenParameter>();
+        List<CodegenParameter> headerParams = new ArrayList<>();
-        List<CodegenParameter> cookieParams = new ArrayList<CodegenParameter>();
+        List<CodegenParameter> cookieParams = new ArrayList<>();
-        List<CodegenParameter> formParams = new ArrayList<CodegenParameter>();
+        List<CodegenParameter> formParams = new ArrayList<>();
-        List<CodegenParameter> requiredParams = new ArrayList<CodegenParameter>();
+        List<CodegenParameter> requiredParams = new ArrayList<>();
-        List<CodegenParameter> optionalParams = new ArrayList<CodegenParameter>();
+        List<CodegenParameter> optionalParams = new ArrayList<>();
 
         CodegenParameter bodyParam = null;
         RequestBody requestBody = operation.getRequestBody();
@@ -4039,7 +4039,7 @@ public class DefaultCodegen implements CodegenConfig {
 
                 // add example
                 if (schemas != null) {
-                    op.requestBodyExamples = new ExampleGenerator(schemas, this.openAPI).generate(null, new ArrayList<String>(getConsumesInfo(this.openAPI, operation)), bodyParam.baseType);
+                    op.requestBodyExamples = new ExampleGenerator(schemas, this.openAPI).generate(null, new ArrayList<>(getConsumesInfo(this.openAPI, operation)), bodyParam.baseType);
                 }
             }
         }
@@ -4531,7 +4531,7 @@ public class DefaultCodegen implements CodegenConfig {
             return codegenParameter;
         }
 
-        parameterSchema = unaliasSchema(parameterSchema, Collections.<String, String>emptyMap());
+        parameterSchema = unaliasSchema(parameterSchema, Collections.emptyMap());
         if (parameterSchema == null) {
             LOGGER.warn("warning!  Schema not found for parameter \" {} \", using String", parameter.getName());
             parameterSchema = new StringSchema().description("//TODO automatically added by openapi-generator due to missing type definition.");
@@ -4755,7 +4755,7 @@ public class DefaultCodegen implements CodegenConfig {
             return Collections.emptyList();
         }
 
-        List<CodegenSecurity> codegenSecurities = new ArrayList<CodegenSecurity>(securitySchemeMap.size());
+        List<CodegenSecurity> codegenSecurities = new ArrayList<>(securitySchemeMap.size());
         for (String key : securitySchemeMap.keySet()) {
             final SecurityScheme securityScheme = securitySchemeMap.get(key);
             if (SecurityScheme.Type.APIKEY.equals(securityScheme.getType())) {
@@ -4855,7 +4855,7 @@ public class DefaultCodegen implements CodegenConfig {
     }
 
     protected void setReservedWordsLowerCase(List<String> words) {
-        reservedWords = new HashSet<String>();
+        reservedWords = new HashSet<>();
         for (String word : words) {
             reservedWords.add(word.toLowerCase(Locale.ROOT));
         }
@@ -4918,9 +4918,9 @@ public class DefaultCodegen implements CodegenConfig {
             return null;
         }
 
-        final List<Map<String, Object>> output = new ArrayList<Map<String, Object>>(examples.size());
+        final List<Map<String, Object>> output = new ArrayList<>(examples.size());
         for (Map.Entry<String, Object> entry : examples.entrySet()) {
-            final Map<String, Object> kv = new HashMap<String, Object>();
+            final Map<String, Object> kv = new HashMap<>();
             kv.put("contentType", entry.getKey());
             kv.put("example", entry.getValue());
             output.add(kv);
@@ -4976,7 +4976,7 @@ public class DefaultCodegen implements CodegenConfig {
             co, Map<String, List<CodegenOperation>> operations) {
         List<CodegenOperation> opList = operations.get(tag);
         if (opList == null) {
-            opList = new ArrayList<CodegenOperation>();
+            opList = new ArrayList<>();
             operations.put(tag, opList);
         }
         // check for operationId uniqueness
@@ -5084,8 +5084,8 @@ public class DefaultCodegen implements CodegenConfig {
             m.hasVars = true;
             m.hasEnums = false; // TODO need to fix as its false in both cases
 
-            Set<String> mandatory = required == null ? Collections.<String>emptySet()
+            Set<String> mandatory = required == null ? Collections.emptySet()
-                    : new TreeSet<String>(required);
+                    : new TreeSet<>(required);
 
             // update "vars" without parent's properties (all, required)
             addVars(m, m.vars, properties, mandatory);
@@ -5097,8 +5097,8 @@ public class DefaultCodegen implements CodegenConfig {
         }
 
         if (allProperties != null) {
-            Set<String> allMandatory = allRequired == null ? Collections.<String>emptySet()
+            Set<String> allMandatory = allRequired == null ? Collections.emptySet()
-                    : new TreeSet<String>(allRequired);
+                    : new TreeSet<>(allRequired);
             // update "vars" with parent's properties (all, required)
             addVars(m, m.allVars, allProperties, allMandatory);
             m.allMandatory = allMandatory;
@@ -5108,14 +5108,14 @@ public class DefaultCodegen implements CodegenConfig {
         }
 
         // loop through list to update property name with toVarName
-        Set<String> renamedMandatory = new ConcurrentSkipListSet<String>();
+        Set<String> renamedMandatory = new ConcurrentSkipListSet<>();
         Iterator<String> mandatoryIterator = m.mandatory.iterator();
         while (mandatoryIterator.hasNext()) {
             renamedMandatory.add(toVarName(mandatoryIterator.next()));
         }
         m.mandatory = renamedMandatory;
 
-        Set<String> renamedAllMandatory = new ConcurrentSkipListSet<String>();
+        Set<String> renamedAllMandatory = new ConcurrentSkipListSet<>();
         Iterator<String> allMandatoryIterator = m.allMandatory.iterator();
         while (allMandatoryIterator.hasNext()) {
             renamedAllMandatory.add(toVarName(allMandatoryIterator.next()));
@@ -5568,7 +5568,7 @@ public class DefaultCodegen implements CodegenConfig {
      * @return sanitized string
      */
     public String sanitizeName(String name, String removeCharRegEx) {
-        return sanitizeName(name, removeCharRegEx, new ArrayList<String>());
+        return sanitizeName(name, removeCharRegEx, new ArrayList<>());
     }
 
     /**
@@ -5827,7 +5827,7 @@ public class DefaultCodegen implements CodegenConfig {
                 enumName = String.valueOf(value);
             } else {
                 enumName = value.toString().substring(truncateIdx);
-                if ("".equals(enumName)) {
+                if (enumName.isEmpty()) {
                     enumName = value.toString();
                 }
             }
@@ -6057,7 +6057,7 @@ public class DefaultCodegen implements CodegenConfig {
             return null;
         }
 
-        Set<String> produces = new ConcurrentSkipListSet<String>();
+        Set<String> produces = new ConcurrentSkipListSet<>();
 
         for (ApiResponse r : operation.getResponses().values()) {
             ApiResponse response = ModelUtils.getReferencedApiResponse(openAPI, r);
@@ -6108,7 +6108,7 @@ public class DefaultCodegen implements CodegenConfig {
         LOGGER.debug("debugging fromRequestBodyToFormParameters= {}", body);
         Schema schema = ModelUtils.getSchemaFromRequestBody(body);
         schema = ModelUtils.getReferencedSchema(this.openAPI, schema);
-        List<String> allRequired = new ArrayList<String>();
+        List<String> allRequired = new ArrayList<>();
         Map<String, Schema> properties = new LinkedHashMap<>();
         // this traverses a composed schema and extracts all properties in each schema into properties
         // TODO in the future have this return one codegenParameter of type object or composed which includes all definition
@@ -6289,7 +6289,7 @@ public class DefaultCodegen implements CodegenConfig {
             codegenParameter.datatypeWithEnum = codegenProperty.datatypeWithEnum;
             codegenParameter.enumName = codegenProperty.enumName;
         }
-        
+
         // import
         if (codegenProperty.complexType != null) {
             imports.add(codegenProperty.complexType);
@@ -6953,7 +6953,7 @@ public class DefaultCodegen implements CodegenConfig {
         cm.name = type;
         cm.classname = type;
         cm.vendorExtensions.put("x-is-one-of-interface", true);
-        cm.interfaceModels = new ArrayList<CodegenModel>();
+        cm.interfaceModels = new ArrayList<>();
 
         addOneOfInterfaces.add(cm);
     }
@@ -7171,7 +7171,7 @@ public class DefaultCodegen implements CodegenConfig {
         List<CodegenProperty> xOf = new ArrayList<>();
         int i = 0;
         for (Schema xOfSchema: xOfCollection) {
-            CodegenProperty cp = fromProperty(collectionName + "_" + String.valueOf(i), xOfSchema);
+            CodegenProperty cp = fromProperty(collectionName + "_" + i, xOfSchema);
             xOf.add(cp);
             i += 1;
         }

modules/openapi-generator/src/main/java/org/openapitools/codegen/SpecValidationException.java

@@ -129,6 +129,6 @@ public class SpecValidationException extends RuntimeException {
         });
 
         return super.getMessage() + " | " +
-                "Error count: " + errorCount + ", Warning count: " + warningCount + sb.toString();
+                "Error count: " + errorCount + ", Warning count: " + warningCount + sb;
     }
 }

modules/openapi-generator/src/main/java/org/openapitools/codegen/TemplateManager.java

@@ -103,7 +103,7 @@ public class TemplateManager implements TemplatingExecutor, TemplateProcessor {
      * @param name The location of the template
      * @return The raw template contents
      */
-    @SuppressWarnings({"java:S112"})
+    @SuppressWarnings("java:S112")
     // ignored rule java:S112 as RuntimeException is used to match previous exception type
     public String readTemplate(String name) {
         if (name == null || name.contains("..")) {

modules/openapi-generator/src/main/java/org/openapitools/codegen/TemplatingEngineLoader.java

@@ -26,7 +26,7 @@ public class TemplatingEngineLoader {
         throw new IllegalStateException("Utility class");
     }
 
-    @SuppressWarnings({"java:S112"}) // ignore java:S112 as generic RuntimeException is acceptable here
+    @SuppressWarnings("java:S112") // ignore java:S112 as generic RuntimeException is acceptable here
     public static TemplatingEngineAdapter byIdentifier(String id) {
         ServiceLoader<TemplatingEngineAdapter> loader = ServiceLoader.load(TemplatingEngineAdapter.class, TemplatingEngineLoader.class.getClassLoader());
 
@@ -42,7 +42,7 @@ public class TemplatingEngineLoader {
             // Attempt to load skipping SPI
             return (TemplatingEngineAdapter) Class.forName(id).getDeclaredConstructor().newInstance();
         } catch (Exception e) {
-            throw new RuntimeException(String.format(Locale.ROOT, "Couldn't load template engine adapter %s. Available options: %n%s", id, sb.toString()), e);
+            throw new RuntimeException(String.format(Locale.ROOT, "Couldn't load template engine adapter %s. Available options: %n%s", id, sb), e);
         }
     }
 }

modules/openapi-generator/src/main/java/org/openapitools/codegen/config/CodegenConfigurator.java

@@ -535,9 +535,7 @@ public class CodegenConfigurator {
             Set<String> warnings = new HashSet<>();
             if (specification != null) {
                 List<String> unusedModels = ModelUtils.getUnusedSchemas(specification);
-                if (unusedModels != null) {
+                unusedModels.forEach(name -> warnings.add("Unused model: " + name));
-                    unusedModels.forEach(name -> warnings.add("Unused model: " + name));
-                }
             }
 
             if (workflowSettings.isValidateSpec()) {

modules/openapi-generator/src/main/java/org/openapitools/codegen/examples/ExampleGenerator.java

@@ -165,7 +165,7 @@ public class ExampleGenerator {
                     }
                 } else if (modelName != null && mediaType.startsWith(MIME_TYPE_XML)) {
                     final Schema schema = this.examples.get(modelName);
-                    String example = new XmlExampleGenerator(this.examples).toXml(schema, 0, Collections.<String>emptySet());
+                    String example = new XmlExampleGenerator(this.examples).toXml(schema, 0, Collections.emptySet());
                     if (example != null) {
                         kv.put(EXAMPLE, example);
                         output.add(kv);

modules/openapi-generator/src/main/java/org/openapitools/codegen/examples/XmlExampleGenerator.java

@@ -44,7 +44,7 @@ public class XmlExampleGenerator {
     }
 
     public String toXml(Schema schema) {
-        return toXml(null, schema, 0, Collections.<String>emptySet());
+        return toXml(null, schema, 0, Collections.emptySet());
     }
 
     protected String toXml(Schema schema, int indent, Collection<String> path) {

modules/openapi-generator/src/main/java/org/openapitools/codegen/ignore/rules/RootedFileRule.java

@@ -41,7 +41,7 @@ public class RootedFileRule extends Rule {
     }
 
     private String getExtensionPart(final String input, int stopIndex) {
-        return input.substring(stopIndex > 0 ? stopIndex+1: input.length(), input.length());
+        return input.substring(stopIndex > 0 ? stopIndex+1: input.length());
     }
 
     @Override

modules/openapi-generator/src/main/java/org/openapitools/codegen/languages/AbstractAdaCodegen.java

@@ -50,7 +50,7 @@ abstract public class AbstractAdaCodegen extends DefaultCodegen implements Codeg
     protected List<Map<String, Object>> orderedModels;
     protected final Map<String, List<String>> modelDepends;
     protected final Map<String, String> nullableTypeMapping;
-    protected final HashMap<String, String> operationsScopes;
+    protected final Map<String, String> operationsScopes;
     protected int scopeIndex = 0;
 
     public AbstractAdaCodegen() {
@@ -155,7 +155,7 @@ abstract public class AbstractAdaCodegen extends DefaultCodegen implements Codeg
                         "xor")
         );
 
-        typeMapping = new HashMap<String, String>();
+        typeMapping = new HashMap<>();
         typeMapping.put("date", "Swagger.Date");
         typeMapping.put("DateTime", "Swagger.Datetime");
         typeMapping.put("string", "Swagger.UString");
@@ -172,7 +172,7 @@ abstract public class AbstractAdaCodegen extends DefaultCodegen implements Codeg
         typeMapping.put("binary", "Swagger.Binary");
 
         // Mapping to convert an Ada required type to an optional type (nullable).
-        nullableTypeMapping = new HashMap<String, String>();
+        nullableTypeMapping = new HashMap<>();
         nullableTypeMapping.put("Swagger.Date", "Swagger.Nullable_Date");
         nullableTypeMapping.put("Swagger.Datetime", "Swagger.Nullable_Date");
         nullableTypeMapping.put("Swagger.UString", "Swagger.Nullable_UString");
@@ -181,10 +181,10 @@ abstract public class AbstractAdaCodegen extends DefaultCodegen implements Codeg
         nullableTypeMapping.put("Boolean", "Swagger.Nullable_Boolean");
         nullableTypeMapping.put("Swagger.Object", "Swagger.Object");
 
-        modelDepends = new HashMap<String, List<String>>();
+        modelDepends = new HashMap<>();
-        orderedModels = new ArrayList<Map<String, Object>>();
+        orderedModels = new ArrayList<>();
-        operationsScopes = new HashMap<String, String>();
+        operationsScopes = new HashMap<>();
-        super.importMapping = new HashMap<String, String>();
+        super.importMapping = new HashMap<>();
 
         // CLI options
         addOption(CodegenConstants.PROJECT_NAME, "GNAT project name",
@@ -193,7 +193,7 @@ abstract public class AbstractAdaCodegen extends DefaultCodegen implements Codeg
         modelNameSuffix = "Type";
         embeddedTemplateDir = templateDir = "Ada";
 
-        languageSpecificPrimitives = new HashSet<String>(
+        languageSpecificPrimitives = new HashSet<>(
                 Arrays.asList("integer", "boolean", "number", "long", "float",
                         "double", "object", "string", "date", "DateTime", "binary"));
     }
@@ -651,7 +651,7 @@ abstract public class AbstractAdaCodegen extends DefaultCodegen implements Codeg
             Object v = model.get("model");
             if (v instanceof CodegenModel) {
                 CodegenModel m = (CodegenModel) v;
-                List<String> d = new ArrayList<String>();
+                List<String> d = new ArrayList<>();
                 for (CodegenProperty p : m.vars) {
                     boolean isModel = false;
                     CodegenProperty item = p;
@@ -687,8 +687,8 @@ abstract public class AbstractAdaCodegen extends DefaultCodegen implements Codeg
         //     if I find a model that has no dependencies, or all of its dependencies are in revisedOrderedModels, consider it the independentModel
         //   put the independentModel at the end of revisedOrderedModels, and remove it from orderedModels
         //
-        List<Map<String, Object>> revisedOrderedModels = new ArrayList<Map<String, Object>>();
+        List<Map<String, Object>> revisedOrderedModels = new ArrayList<>();
-        List<String> collectedModelNames = new ArrayList<String>();
+        List<String> collectedModelNames = new ArrayList<>();
         int sizeOrderedModels = orderedModels.size();
         for (int i = 0; i < sizeOrderedModels; i++) {
             Map<String, Object> independentModel = null;
@@ -760,7 +760,7 @@ abstract public class AbstractAdaCodegen extends DefaultCodegen implements Codeg
      * @return the authMethods to be used by the operation with its required scopes.
      */
     private List<CodegenSecurity> postProcessAuthMethod(List<CodegenSecurity> authMethods, Map<String, List<String>> scopes) {
-        List<CodegenSecurity> result = (scopes == null) ? null : new ArrayList<CodegenSecurity>();
+        List<CodegenSecurity> result = (scopes == null) ? null : new ArrayList<>();
         if (authMethods != null) {
             for (CodegenSecurity authMethod : authMethods) {
                 if (authMethod.scopes != null) {
@@ -803,7 +803,7 @@ abstract public class AbstractAdaCodegen extends DefaultCodegen implements Codeg
                     opSecurity.isKeyInQuery = authMethod.isKeyInQuery;
                     opSecurity.flow = authMethod.flow;
                     opSecurity.tokenUrl = authMethod.tokenUrl;
-                    List<Map<String, Object>> opAuthScopes = new ArrayList<Map<String, Object>>();
+                    List<Map<String, Object>> opAuthScopes = new ArrayList<>();
                     for (String opScopeName : opScopes) {
                         for (Map<String, Object> scope : authMethod.scopes) {
                             String name = (String) scope.get("scope");

modules/openapi-generator/src/main/java/org/openapitools/codegen/languages/AbstractCSharpCodegen.java

@@ -81,9 +81,9 @@ public abstract class AbstractCSharpCodegen extends DefaultCodegen implements Co
     protected boolean supportNullable = Boolean.FALSE;
 
     // nullable type
-    protected Set<String> nullableType = new HashSet<String>();
+    protected Set<String> nullableType = new HashSet<>();
 
-    protected Set<String> valueTypes = new HashSet<String>();
+    protected Set<String> valueTypes = new HashSet<>();
 
     private final Logger LOGGER = LoggerFactory.getLogger(AbstractCSharpCodegen.class);
 
@@ -104,14 +104,14 @@ public abstract class AbstractCSharpCodegen extends DefaultCodegen implements Co
         outputFolder = "generated-code" + File.separator + this.getName();
         embeddedTemplateDir = templateDir = this.getName();
 
-        collectionTypes = new HashSet<String>(
+        collectionTypes = new HashSet<>(
                 Arrays.asList(
                         "IList", "List",
                         "ICollection", "Collection",
                         "IEnumerable")
         );
 
-        mapTypes = new HashSet<String>(
+        mapTypes = new HashSet<>(
                 Arrays.asList("IDictionary")
         );
 
@@ -141,7 +141,7 @@ public abstract class AbstractCSharpCodegen extends DefaultCodegen implements Co
         );
 
         // TODO: Either include fully qualified names here or handle in DefaultCodegen via lastIndexOf(".") search
-        languageSpecificPrimitives = new HashSet<String>(
+        languageSpecificPrimitives = new HashSet<>(
                 Arrays.asList(
                         "String",
                         "string",
@@ -184,7 +184,7 @@ public abstract class AbstractCSharpCodegen extends DefaultCodegen implements Co
 
 
         // Nullable types here assume C# 2 support is not part of base
-        typeMapping = new HashMap<String, String>();
+        typeMapping = new HashMap<>();
         typeMapping.put("string", "string");
         typeMapping.put("binary", "byte[]");
         typeMapping.put("ByteArray", "byte[]");
@@ -207,11 +207,11 @@ public abstract class AbstractCSharpCodegen extends DefaultCodegen implements Co
         typeMapping.put("AnyType", "Object");
 
         // nullable type
-        nullableType = new HashSet<String>(
+        nullableType = new HashSet<>(
                 Arrays.asList("decimal", "bool", "int", "float", "long", "double", "DateTime", "DateTimeOffset", "Guid")
         );
         // value Types
-        valueTypes = new HashSet<String>(
+        valueTypes = new HashSet<>(
                 Arrays.asList("decimal", "bool", "int", "float", "long", "double")
         );
     }
@@ -463,9 +463,9 @@ public abstract class AbstractCSharpCodegen extends DefaultCodegen implements Co
      *
      * @param models processed models to be further processed for enum references
      */
-    @SuppressWarnings({"unchecked"})
+    @SuppressWarnings("unchecked")
     private void postProcessEnumRefs(final Map<String, Object> models) {
-        Map<String, CodegenModel> enumRefs = new HashMap<String, CodegenModel>();
+        Map<String, CodegenModel> enumRefs = new HashMap<>();
         for (Map.Entry<String, Object> entry : models.entrySet()) {
             CodegenModel model = ModelUtils.getModelByName(entry.getKey(), models);
             if (model.isEnum) {
@@ -1325,7 +1325,7 @@ public abstract class AbstractCSharpCodegen extends DefaultCodegen implements Co
 
         // only process files with .cs extension
         if ("cs".equals(FilenameUtils.getExtension(file.toString()))) {
-            String command = csharpPostProcessFile + " " + file.toString();
+            String command = csharpPostProcessFile + " " + file;
             try {
                 Process p = Runtime.getRuntime().exec(command);
                 int exitValue = p.waitFor();

modules/openapi-generator/src/main/java/org/openapitools/codegen/languages/AbstractCppCodegen.java

@@ -323,7 +323,7 @@ abstract public class AbstractCppCodegen extends DefaultCodegen implements Codeg
         }
         // only process files with cpp extension
         if ("cpp".equals(FilenameUtils.getExtension(file.toString())) || "h".equals(FilenameUtils.getExtension(file.toString()))) {
-            String command = cppPostProcessFile + " " + file.toString();
+            String command = cppPostProcessFile + " " + file;
             try {
                 Process p = Runtime.getRuntime().exec(command);
                 p.waitFor();

modules/openapi-generator/src/main/java/org/openapitools/codegen/languages/AbstractDartCodegen.java

@@ -340,7 +340,7 @@ public abstract class AbstractDartCodegen extends DefaultCodegen {
 
         // replace all characters that have a mapping but ignore underscores
         // append an underscore to each replacement so that it can be camelized
-        if (name.chars().anyMatch(character -> specialCharReplacements.containsKey("" + ((char) character)))) {
+        if (name.chars().anyMatch(character -> specialCharReplacements.containsKey(String.valueOf((char) character)))) {
             name = escape(name, specialCharReplacements, Collections.singletonList("_"), "_");
         }
         // remove the rest
@@ -752,7 +752,7 @@ public abstract class AbstractDartCodegen extends DefaultCodegen {
         // process all files with dart extension
         if ("dart".equals(FilenameUtils.getExtension(file.toString()))) {
             // currently supported is "dartfmt -w" and "dart format"
-            String command = dartPostProcessFile + " " + file.toString();
+            String command = dartPostProcessFile + " " + file;
             try {
                 Process p = Runtime.getRuntime().exec(command);
                 int exitValue = p.waitFor();

modules/openapi-generator/src/main/java/org/openapitools/codegen/languages/AbstractEiffelCodegen.java

@@ -53,9 +53,9 @@ public abstract class AbstractEiffelCodegen extends DefaultCodegen implements Co
                 "redefine", "rename", "require", "rescue", "Result", "retry", "select", "separate", "then", "True",
                 "TUPLE", "undefine", "until", "variant", "Void", "when", "xor"));
 
-        defaultIncludes = new HashSet<String>(Arrays.asList("map", "array"));
+        defaultIncludes = new HashSet<>(Arrays.asList("map", "array"));
 
-        languageSpecificPrimitives = new HashSet<String>(
+        languageSpecificPrimitives = new HashSet<>(
                 Arrays.asList("BOOLEAN", "INTEGER_8", "INTEGER_16", "INTEGER_32", "INTEGER_64", "NATURAL_8",
                         "NATURAL_16", "NATURAL_32", "NATURAL_64", "REAL_32", "REAL_64"));
 
@@ -559,7 +559,7 @@ public abstract class AbstractEiffelCodegen extends DefaultCodegen implements Co
     }
 
     public Map<String, String> createMapping(String key, String value) {
-        Map<String, String> customImport = new HashMap<String, String>();
+        Map<String, String> customImport = new HashMap<>();
         customImport.put(key, value);
 
         return customImport;
@@ -592,7 +592,7 @@ public abstract class AbstractEiffelCodegen extends DefaultCodegen implements Co
 
     public String toEiffelFeatureStyle(String operationId) {
         if (operationId.startsWith("get_")) {
-            return operationId.substring(4, operationId.length());
+            return operationId.substring(4);
         } else {
             return operationId;
         }

modules/openapi-generator/src/main/java/org/openapitools/codegen/languages/AbstractFSharpCodegen.java

@@ -73,7 +73,7 @@ public abstract class AbstractFSharpCodegen extends DefaultCodegen implements Co
     // true if nullable types will be supported (as option)
     protected boolean supportNullable = Boolean.TRUE;
 
-    protected Set<String> nullableType = new HashSet<String>();
+    protected Set<String> nullableType = new HashSet<>();
 
 
     private final Logger LOGGER = LoggerFactory.getLogger(AbstractFSharpCodegen.class);
@@ -89,9 +89,9 @@ public abstract class AbstractFSharpCodegen extends DefaultCodegen implements Co
         outputFolder = this.getName();
         embeddedTemplateDir = templateDir = this.getName();
 
-        collectionTypes = new HashSet<String>(Arrays.asList("list", "seq"));
+        collectionTypes = new HashSet<>(Arrays.asList("list", "seq"));
 
-        mapTypes = new HashSet<String>(
+        mapTypes = new HashSet<>(
                 Arrays.asList("IDictionary")
         );
 
@@ -114,7 +114,7 @@ public abstract class AbstractFSharpCodegen extends DefaultCodegen implements Co
         );
 
         // TODO - these are based on C# generator, do we need to add any more?
-        languageSpecificPrimitives = new HashSet<String>(
+        languageSpecificPrimitives = new HashSet<>(
                 Arrays.asList(
                         "String",
                         "string",
@@ -156,7 +156,7 @@ public abstract class AbstractFSharpCodegen extends DefaultCodegen implements Co
         instantiationTypes.put("map", "IDictionary");
 
 
-        typeMapping = new HashMap<String, String>();
+        typeMapping = new HashMap<>();
         typeMapping.put("string", "string");
         typeMapping.put("binary", "byte[]");
         typeMapping.put("ByteArray", "byte[]");
@@ -177,7 +177,7 @@ public abstract class AbstractFSharpCodegen extends DefaultCodegen implements Co
         typeMapping.put("URI", "string");
 
         // nullable type
-        nullableType = new HashSet<String>(
+        nullableType = new HashSet<>(
                 Arrays.asList("decimal", "bool", "int", "float", "long", "double", "string", "Guid", "apiKey")
         );
     }
@@ -349,12 +349,12 @@ public abstract class AbstractFSharpCodegen extends DefaultCodegen implements Co
      * Output of CodeGen models must therefore be in dependency order (rather than alphabetical order, which seems to be the default).
      * This could probably be made more efficient if absolutely needed.
      */
-    @SuppressWarnings({"unchecked"})
+    @SuppressWarnings("unchecked")
     public Map<String, Object> postProcessDependencyOrders(final Map<String, Object> objs) {
 
-        Map<String, Set<String>> dependencies = new HashMap<String, Set<String>>();
+        Map<String, Set<String>> dependencies = new HashMap<>();
 
-        List<String> classNames = new ArrayList<String>();
+        List<String> classNames = new ArrayList<>();
 
         for (String k : objs.keySet()) {
             CodegenModel model = ModelUtils.getModelByName(k, objs);
@@ -381,7 +381,7 @@ public abstract class AbstractFSharpCodegen extends DefaultCodegen implements Co
             }
         }
 
-        Map<String, Object> sorted = new LinkedHashMap<String, Object>();
+        Map<String, Object> sorted = new LinkedHashMap<>();
         for (int i = sortedKeys.length - 1; i >= 0; i--) {
             Object k = sortedKeys[i];
             sorted.put(k.toString(), objs.get(k));
@@ -400,9 +400,9 @@ public abstract class AbstractFSharpCodegen extends DefaultCodegen implements Co
      *
      * @param models processed models to be further processed for enum references
      */
-    @SuppressWarnings({"unchecked"})
+    @SuppressWarnings("unchecked")
     private void postProcessEnumRefs(final Map<String, Object> models) {
-        Map<String, CodegenModel> enumRefs = new HashMap<String, CodegenModel>();
+        Map<String, CodegenModel> enumRefs = new HashMap<>();
         for (Map.Entry<String, Object> entry : models.entrySet()) {
             CodegenModel model = ModelUtils.getModelByName(entry.getKey(), models);
             if (model.isEnum) {
@@ -455,10 +455,9 @@ public abstract class AbstractFSharpCodegen extends DefaultCodegen implements Co
                     // Since we iterate enumVars for modelInnerEnum and enumClass templates, and CodegenModel is missing some of CodegenProperty's properties,
                     // we can take advantage of Mustache's contextual lookup to add the same "properties" to the model's enumVars scope rather than CodegenProperty's scope.
                     List<Map<String, String>> enumVars = (ArrayList<Map<String, String>>) model.allowableValues.get("enumVars");
-                    List<Map<String, Object>> newEnumVars = new ArrayList<Map<String, Object>>();
+                    List<Map<String, Object>> newEnumVars = new ArrayList<>();
                     for (Map<String, String> enumVar : enumVars) {
-                        Map<String, Object> mixedVars = new HashMap<String, Object>();
+                        Map<String, Object> mixedVars = new HashMap<>(enumVar);
-                        mixedVars.putAll(enumVar);
 
                         mixedVars.put("isString", isString);
                         mixedVars.put("isLong", isLong);
@@ -473,7 +472,7 @@ public abstract class AbstractFSharpCodegen extends DefaultCodegen implements Co
                     }
                 }
             } else {
-                LOGGER.warn("Expected to retrieve model %s by name, but no model was found. Check your -Dmodels inclusions.", openAPIName);
+                LOGGER.warn("Expected to retrieve model {} by name, but no model was found. Check your -Dmodels inclusions.", openAPIName);
             }
         }
     }
@@ -1115,7 +1114,7 @@ public abstract class AbstractFSharpCodegen extends DefaultCodegen implements Co
 
         // only process files with .fs extension
         if ("fs".equals(FilenameUtils.getExtension(file.toString()))) {
-            String command = fsharpPostProcessFile + " " + file.toString();
+            String command = fsharpPostProcessFile + " " + file;
             try {
                 Process p = Runtime.getRuntime().exec(command);
                 int exitValue = p.waitFor();

modules/openapi-generator/src/main/java/org/openapitools/codegen/languages/AbstractGoCodegen.java

@@ -56,7 +56,7 @@ public abstract class AbstractGoCodegen extends DefaultCodegen implements Codege
         supportsInheritance = true;
         hideGenerationTimestamp = Boolean.FALSE;
 
-        defaultIncludes = new HashSet<String>(
+        defaultIncludes = new HashSet<>(
                 Arrays.asList(
                         "map",
                         "array")
@@ -77,7 +77,7 @@ public abstract class AbstractGoCodegen extends DefaultCodegen implements Codege
                 // Added "error" as it's used so frequently that it may as well be a keyword
         );
 
-        languageSpecificPrimitives = new HashSet<String>(
+        languageSpecificPrimitives = new HashSet<>(
                 Arrays.asList(
                         "string",
                         "bool",
@@ -133,14 +133,14 @@ public abstract class AbstractGoCodegen extends DefaultCodegen implements Codege
         typeMapping.put("object", "map[string]interface{}");
         typeMapping.put("AnyType", "interface{}");
 
-        numberTypes = new HashSet<String>(
+        numberTypes = new HashSet<>(
                 Arrays.asList(
                         "uint", "uint8", "uint16", "uint32", "uint64",
                         "int", "int8", "int16", "int32", "int64",
                         "float32", "float64")
         );
 
-        importMapping = new HashMap<String, String>();
+        importMapping = new HashMap<>();
 
         cliOptions.clear();
         cliOptions.add(new CliOption(CodegenConstants.PACKAGE_NAME, "Go package name (convention: lowercase).")
@@ -252,7 +252,7 @@ public abstract class AbstractGoCodegen extends DefaultCodegen implements Codege
         String[] parts = name.split("_");
         String suffix = parts[parts.length - 1];
 
-        Set<String> reservedSuffixes = new HashSet<String>(Arrays.asList(
+        Set<String> reservedSuffixes = new HashSet<>(Arrays.asList(
                 // Test
                 "test",
                 // $GOOS
@@ -699,7 +699,7 @@ public abstract class AbstractGoCodegen extends DefaultCodegen implements Codege
     }
 
     public Map<String, String> createMapping(String key, String value) {
-        Map<String, String> customImport = new HashMap<String, String>();
+        Map<String, String> customImport = new HashMap<>();
         customImport.put(key, value);
 
         return customImport;
@@ -813,7 +813,7 @@ public abstract class AbstractGoCodegen extends DefaultCodegen implements Codege
         }
 
         // only process the following type (or we can simply rely on the file extension to check if it's a Go file)
-        Set<String> supportedFileType = new HashSet<String>(
+        Set<String> supportedFileType = new HashSet<>(
                 Arrays.asList(
                         "supporting-mustache",
                         "model-test",
@@ -828,7 +828,7 @@ public abstract class AbstractGoCodegen extends DefaultCodegen implements Codege
         if ("go".equals(FilenameUtils.getExtension(file.toString()))) {
             // e.g. "gofmt -w yourcode.go"
             // e.g. "go fmt path/to/your/package"
-            String command = goPostProcessFile + " " + file.toString();
+            String command = goPostProcessFile + " " + file;
             try {
                 Process p = Runtime.getRuntime().exec(command);
                 int exitValue = p.waitFor();

modules/openapi-generator/src/main/java/org/openapitools/codegen/languages/AbstractGraphQLCodegen.java

@@ -55,13 +55,13 @@ public abstract class AbstractGraphQLCodegen extends DefaultCodegen implements C
                 )
         );
 
-        defaultIncludes = new HashSet<String>(
+        defaultIncludes = new HashSet<>(
                 Arrays.asList(
                         "map",
                         "array")
         );
 
-        languageSpecificPrimitives = new HashSet<String>(
+        languageSpecificPrimitives = new HashSet<>(
                 Arrays.asList(
                         "null",
                         "ID",
@@ -344,7 +344,7 @@ public abstract class AbstractGraphQLCodegen extends DefaultCodegen implements C
     }
 
     public Map<String, String> createMapping(String key, String value) {
-        Map<String, String> customImport = new HashMap<String, String>();
+        Map<String, String> customImport = new HashMap<>();
         customImport.put(key, value);
 
         return customImport;

modules/openapi-generator/src/main/java/org/openapitools/codegen/languages/AbstractJavaCodegen.java

@@ -18,6 +18,7 @@
 package org.openapitools.codegen.languages;
 
 import com.google.common.base.Strings;
+import com.google.common.collect.Sets;
 import io.swagger.v3.oas.models.OpenAPI;
 import io.swagger.v3.oas.models.Operation;
 import io.swagger.v3.oas.models.PathItem;
@@ -164,9 +165,7 @@ public abstract class AbstractJavaCodegen extends DefaultCodegen implements Code
                         "native", "super", "while", "null")
         );
 
-        languageSpecificPrimitives = new HashSet<String>(
+        languageSpecificPrimitives = Sets.newHashSet("String",
-                Arrays.asList(
-                        "String",
                         "boolean",
                         "Boolean",
                         "Double",
@@ -174,7 +173,7 @@ public abstract class AbstractJavaCodegen extends DefaultCodegen implements Code
                         "Long",
                         "Float",
                         "Object",
-                        "byte[]")
+                        "byte[]"
         );
         instantiationTypes.put("array", "ArrayList");
         instantiationTypes.put("set", "LinkedHashSet");
@@ -713,7 +712,7 @@ public abstract class AbstractJavaCodegen extends DefaultCodegen implements Code
         }
 
         // If name contains special chars -> replace them.
-        if ((((CharSequence) name).chars().anyMatch(character -> specialCharReplacements.keySet().contains("" + ((char) character))))) {
+        if ((((CharSequence) name).chars().anyMatch(character -> specialCharReplacements.containsKey(String.valueOf((char) character))))) {
             List<String> allowedCharacters = new ArrayList<>();
             allowedCharacters.add("_");
             allowedCharacters.add("$");
@@ -996,7 +995,7 @@ public abstract class AbstractJavaCodegen extends DefaultCodegen implements Code
      */
     @Override
     public void setParameterExampleValue(CodegenParameter codegenParameter, RequestBody requestBody) {
-        Boolean isModel = (codegenParameter.isModel || (codegenParameter.isContainer && codegenParameter.getItems().isModel));
+        boolean isModel = (codegenParameter.isModel || (codegenParameter.isContainer && codegenParameter.getItems().isModel));
 
         Content content = requestBody.getContent();
 
@@ -1260,7 +1259,7 @@ public abstract class AbstractJavaCodegen extends DefaultCodegen implements Code
             // if the import package happens to be found in the importMapping (key)
             // add the corresponding import package to the list
             if (importMapping.containsKey(_import)) {
-                Map<String, String> newImportMap = new HashMap<String, String>();
+                Map<String, String> newImportMap = new HashMap<>();
                 newImportMap.put("import", importMapping.get(_import));
                 listIterator.add(newImportMap);
             }
@@ -1285,7 +1284,7 @@ public abstract class AbstractJavaCodegen extends DefaultCodegen implements Code
         Map<String, Object> operations = (Map<String, Object>) objs.get("operations");
         List<CodegenOperation> operationList = (List<CodegenOperation>) operations.get("operation");
         for (CodegenOperation op : operationList) {
-            Collection<String> operationImports = new ConcurrentSkipListSet<String>();
+            Collection<String> operationImports = new ConcurrentSkipListSet<>();
             for (CodegenParameter p : op.allParams) {
                 if (importMapping.containsKey(p.dataType)) {
                     operationImports.add(importMapping.get(p.dataType));
@@ -1314,7 +1313,7 @@ public abstract class AbstractJavaCodegen extends DefaultCodegen implements Code
                     if (hasBodyParameter(openAPI, operation) || hasFormParameter(openAPI, operation)) {
                         String defaultContentType = hasFormParameter(openAPI, operation) ? "application/x-www-form-urlencoded" : "application/json";
                         List<String> consumes = new ArrayList<>(getConsumesInfo(openAPI, operation));
-                        String contentType = consumes == null || consumes.isEmpty() ? defaultContentType : consumes.get(0);
+                        String contentType = consumes.isEmpty() ? defaultContentType : consumes.get(0);
                         operation.addExtension("x-contentType", contentType);
                     }
                     String accepts = getAccept(openAPI, operation);
@@ -1865,7 +1864,7 @@ public abstract class AbstractJavaCodegen extends DefaultCodegen implements Code
 
         // only process files with java extension
         if ("java".equals(FilenameUtils.getExtension(file.toString()))) {
-            String command = javaPostProcessFile + " " + file.toString();
+            String command = javaPostProcessFile + " " + file;
             try {
                 Process p = Runtime.getRuntime().exec(command);
                 p.waitFor();

modules/openapi-generator/src/main/java/org/openapitools/codegen/languages/AbstractJavaJAXRSServerCodegen.java

@@ -66,7 +66,7 @@ public abstract class AbstractJavaJAXRSServerCodegen extends AbstractJavaCodegen
         updateOption(CodegenConstants.ARTIFACT_ID, this.getArtifactId());
         updateOption(CodegenConstants.API_PACKAGE, apiPackage);
         updateOption(CodegenConstants.MODEL_PACKAGE, modelPackage);
-        updateOption(this.DATE_LIBRARY, this.getDateLibrary());
+        updateOption(DATE_LIBRARY, this.getDateLibrary());
 
         additionalProperties.put("title", title);
         // java inflector uses the jackson lib

modules/openapi-generator/src/main/java/org/openapitools/codegen/languages/AbstractKotlinCodegen.java

@@ -78,7 +78,7 @@ public abstract class AbstractKotlinCodegen extends DefaultCodegen implements Co
         supportsInheritance = true;
         setSortModelPropertiesByRequiredFlag(true);
 
-        languageSpecificPrimitives = new HashSet<String>(Arrays.asList(
+        languageSpecificPrimitives = new HashSet<>(Arrays.asList(
                 "kotlin.Byte",
                 "kotlin.ByteArray",
                 "kotlin.Short",
@@ -97,7 +97,7 @@ public abstract class AbstractKotlinCodegen extends DefaultCodegen implements Co
 
         // this includes hard reserved words defined by https://github.com/JetBrains/kotlin/blob/master/core/descriptors/src/org/jetbrains/kotlin/renderer/KeywordStringsGenerated.java
         // as well as keywords from https://kotlinlang.org/docs/reference/keyword-reference.html
-        reservedWords = new HashSet<String>(Arrays.asList(
+        reservedWords = new HashSet<>(Arrays.asList(
                 "abstract",
                 "actual",
                 "annotation",
@@ -171,7 +171,7 @@ public abstract class AbstractKotlinCodegen extends DefaultCodegen implements Co
                 "while"
         ));
 
-        defaultIncludes = new HashSet<String>(Arrays.asList(
+        defaultIncludes = new HashSet<>(Arrays.asList(
                 "kotlin.Byte",
                 "kotlin.ByteArray",
                 "kotlin.Short",
@@ -187,7 +187,7 @@ public abstract class AbstractKotlinCodegen extends DefaultCodegen implements Co
                 "kotlin.collections.Map"
         ));
 
-        typeMapping = new HashMap<String, String>();
+        typeMapping = new HashMap<>();
         typeMapping.put("string", "kotlin.String");
         typeMapping.put("boolean", "kotlin.Boolean");
         typeMapping.put("integer", "kotlin.Int");
@@ -214,7 +214,7 @@ public abstract class AbstractKotlinCodegen extends DefaultCodegen implements Co
         instantiationTypes.put("list", "kotlin.collections.ArrayList");
         instantiationTypes.put("map", "kotlin.collections.HashMap");
 
-        importMapping = new HashMap<String, String>();
+        importMapping = new HashMap<>();
         importMapping.put("BigDecimal", "java.math.BigDecimal");
         importMapping.put("UUID", "java.util.UUID");
         importMapping.put("URI", "java.net.URI");
@@ -896,7 +896,7 @@ public abstract class AbstractKotlinCodegen extends DefaultCodegen implements Co
         }
 
         // If name contains special chars -> replace them.
-        if ((name.chars().anyMatch(character -> specialCharReplacements.keySet().contains("" + ((char) character))))) {
+        if ((name.chars().anyMatch(character -> specialCharReplacements.keySet().contains(String.valueOf((char) character))))) {
             List<String> allowedCharacters = new ArrayList<>();
             allowedCharacters.add("_");
             allowedCharacters.add("$");
@@ -941,7 +941,7 @@ public abstract class AbstractKotlinCodegen extends DefaultCodegen implements Co
 
         // only process files with kt extension
         if ("kt".equals(FilenameUtils.getExtension(file.toString()))) {
-            String command = kotlinPostProcessFile + " " + file.toString();
+            String command = kotlinPostProcessFile + " " + file;
             try {
                 Process p = Runtime.getRuntime().exec(command);
                 p.waitFor();

modules/openapi-generator/src/main/java/org/openapitools/codegen/languages/AbstractPhpCodegen.java

@@ -79,7 +79,7 @@ public abstract class AbstractPhpCodegen extends DefaultCodegen implements Codeg
         );
 
         // ref: http://php.net/manual/en/language.types.intro.php
-        languageSpecificPrimitives = new HashSet<String>(
+        languageSpecificPrimitives = new HashSet<>(
                 Arrays.asList(
                         "bool",
                         "boolean",
@@ -107,7 +107,7 @@ public abstract class AbstractPhpCodegen extends DefaultCodegen implements Codeg
         additionalProperties.put("primitives", primitives);
 
         // ref: https://github.com/OAI/OpenAPI-Specification/blob/master/versions/2.0.md#data-types
-        typeMapping = new HashMap<String, String>();
+        typeMapping = new HashMap<>();
         typeMapping.put("integer", "int");
         typeMapping.put("long", "int");
         typeMapping.put("number", "float");
@@ -769,7 +769,7 @@ public abstract class AbstractPhpCodegen extends DefaultCodegen implements Codeg
         }
         // only process files with php extension
         if ("php".equals(FilenameUtils.getExtension(file.toString()))) {
-            String command = phpPostProcessFile + " " + file.toString();
+            String command = phpPostProcessFile + " " + file;
             try {
                 Process p = Runtime.getRuntime().exec(command);
                 p.waitFor();

modules/openapi-generator/src/main/java/org/openapitools/codegen/languages/AbstractPythonCodegen.java

@@ -270,7 +270,7 @@ public abstract class AbstractPythonCodegen extends DefaultCodegen implements Co
 
         // only process files with py extension
         if ("py".equals(FilenameUtils.getExtension(file.toString()))) {
-            String command = pythonPostProcessFile + " " + file.toString();
+            String command = pythonPostProcessFile + " " + file;
             try {
                 Process p = Runtime.getRuntime().exec(command);
                 int exitValue = p.waitFor();

modules/openapi-generator/src/main/java/org/openapitools/codegen/languages/AbstractRubyCodegen.java

@@ -238,7 +238,7 @@ abstract public class AbstractRubyCodegen extends DefaultCodegen implements Code
         }
         // only process files with rb extension
         if ("rb".equals(FilenameUtils.getExtension(file.toString()))) {
-            String command = rubyPostProcessFile + " " + file.toString();
+            String command = rubyPostProcessFile + " " + file;
             try {
                 Process p = Runtime.getRuntime().exec(command);
                 int exitValue = p.waitFor();
@@ -250,7 +250,7 @@ abstract public class AbstractRubyCodegen extends DefaultCodegen implements Code
                         while ((line = br.readLine()) != null) {
                             sb.append(line);
                         }
-                        LOGGER.error("Error running the command ({}). Exit value: {}, Error output: {}", command, exitValue, sb.toString());
+                        LOGGER.error("Error running the command ({}). Exit value: {}, Error output: {}", command, exitValue, sb);
                     }
                 } else {
                     LOGGER.info("Successfully executed: `{}`", command);

modules/openapi-generator/src/main/java/org/openapitools/codegen/languages/AbstractScalaCodegen.java

@@ -529,7 +529,7 @@ public abstract class AbstractScalaCodegen extends DefaultCodegen {
 
         // only process files with scala extension
         if ("scala".equals(FilenameUtils.getExtension(file.toString()))) {
-            String command = scalaPostProcessFile + " " + file.toString();
+            String command = scalaPostProcessFile + " " + file;
             try {
                 Process p = Runtime.getRuntime().exec(command);
                 int exitValue = p.waitFor();

modules/openapi-generator/src/main/java/org/openapitools/codegen/languages/AbstractTypeScriptClientCodegen.java

@@ -181,7 +181,7 @@ public abstract class AbstractTypeScriptClientCodegen extends DefaultCodegen imp
                 " Required to generate a full package"));
         this.cliOptions.add(new CliOption(NPM_VERSION, "The version of your npm package. If not provided, using the version from the OpenAPI specification file.").defaultValue(this.getNpmVersion()));
         this.cliOptions.add(CliOption.newBoolean(SNAPSHOT,
-                "When setting this property to true, the version will be suffixed with -SNAPSHOT." + this.SNAPSHOT_SUFFIX_FORMAT.get().toPattern(),
+                "When setting this property to true, the version will be suffixed with -SNAPSHOT." + SNAPSHOT_SUFFIX_FORMAT.get().toPattern(),
                 false));
         this.cliOptions.add(new CliOption(NULL_SAFE_ADDITIONAL_PROPS, NULL_SAFE_ADDITIONAL_PROPS_DESC).defaultValue(String.valueOf(this.getNullSafeAdditionalProps())));
     }
@@ -896,7 +896,7 @@ public abstract class AbstractTypeScriptClientCodegen extends DefaultCodegen imp
         }
         // only process files with ts extension
         if ("ts".equals(FilenameUtils.getExtension(file.toString()))) {
-            String command = tsPostProcessFile + " " + file.toString();
+            String command = tsPostProcessFile + " " + file;
             try {
                 Process p = Runtime.getRuntime().exec(command);
                 int exitValue = p.waitFor();

modules/openapi-generator/src/main/java/org/openapitools/codegen/languages/AndroidClientCodegen.java

@@ -117,7 +117,7 @@ public class AndroidClientCodegen extends DefaultCodegen implements CodegenConfi
                         "native", "super", "while", "null")
         );
 
-        languageSpecificPrimitives = new HashSet<String>(
+        languageSpecificPrimitives = new HashSet<>(
                 Arrays.asList(
                         "String",
                         "boolean",

modules/openapi-generator/src/main/java/org/openapitools/codegen/languages/ApexClientCodegen.java

@@ -49,7 +49,7 @@ public class ApexClientCodegen extends AbstractApexCodegen {
     private String namedCredential;
     private String srcPath = "force-app/main/default/";
     private String sfdxConfigPath = "config/";
-    private HashMap<String, Object> primitiveDefaults = new HashMap<String, Object>();
+    private HashMap<String, Object> primitiveDefaults = new HashMap<>();
 
     public ApexClientCodegen() {
         super();
@@ -113,7 +113,7 @@ public class ApexClientCodegen extends AbstractApexCodegen {
                         "virtual", "void", "webservice", "when", "where", "while"
                 ));
 
-        languageSpecificPrimitives = new HashSet<String>(
+        languageSpecificPrimitives = new HashSet<>(
                 Arrays.asList("Blob", "Boolean", "Date", "Datetime", "Decimal", "Double", "ID",
                         "Integer", "Long", "Object", "String", "Time"
                 ));
@@ -233,7 +233,7 @@ public class ApexClientCodegen extends AbstractApexCodegen {
             out = String.valueOf(p.getDefault());
         } else if (ModelUtils.isLongSchema(p)) {
             Long def = (Long) p.getDefault();
-            out = def == null ? out : def.toString() + "L";
+            out = def == null ? out : def + "L";
         } else if (ModelUtils.isMapSchema(p)) {
             Schema inner = getAdditionalProperties(p);
             String s = inner == null ? "Object" : getTypeDeclaration(inner);

modules/openapi-generator/src/main/java/org/openapitools/codegen/languages/AsciidocDocumentationCodegen.java

@@ -89,10 +89,10 @@ public class AsciidocDocumentationCodegen extends DefaultCodegen implements Code
 
             String includeStatement = "include::{" + attributePathReference + "}" + escapeCurlyBrackets(relativeFileName) + "[opts=optional]";
             if (Files.isRegularFile(filePathToInclude)) {
-                LOGGER.debug("including {}. file into markup from: {}", ++includeCount, filePathToInclude.toString());
+                LOGGER.debug("including {}. file into markup from: {}", ++includeCount, filePathToInclude);
                 out.write("\n" + includeStatement + "\n");
             } else {
-                LOGGER.debug("{}. file not found, skip include for: {}", ++notFoundCount, filePathToInclude.toString());
+                LOGGER.debug("{}. file not found, skip include for: {}", ++notFoundCount, filePathToInclude);
                 out.write("\n// markup not found, no " + includeStatement + "\n");
             }
         }
@@ -140,10 +140,10 @@ public class AsciidocDocumentationCodegen extends DefaultCodegen implements Code
             final Path filePathToLinkTo = Paths.get(basePath, relativeFileName).toAbsolutePath();
 
             if (Files.isRegularFile(filePathToLinkTo)) {
-                LOGGER.debug("linking {}. file into markup from: {}", ++linkedCount, filePathToLinkTo.toString());
+                LOGGER.debug("linking {}. file into markup from: {}", ++linkedCount, filePathToLinkTo);
                 out.write("\n" + linkName + " link:" + relativeFileName + "[]\n");
             } else {
-                LOGGER.debug("{}. file not found, skip link for: {}", ++notFoundLinkCount, filePathToLinkTo.toString());
+                LOGGER.debug("{}. file not found, skip link for: {}", ++notFoundLinkCount, filePathToLinkTo);
                 out.write("\n// file not found, no " + linkName + " link :" + relativeFileName + "[]\n");
             }
         }
@@ -217,7 +217,7 @@ public class AsciidocDocumentationCodegen extends DefaultCodegen implements Code
         outputFolder = "generated-code" + File.separator + "asciidoc";
         embeddedTemplateDir = templateDir = "asciidoc-documentation";
 
-        defaultIncludes = new HashSet<String>();
+        defaultIncludes = new HashSet<>();
 
         cliOptions.add(new CliOption("appName", "short name of the application"));
         cliOptions.add(new CliOption("appDescription", "description of the application"));
@@ -264,10 +264,10 @@ public class AsciidocDocumentationCodegen extends DefaultCodegen implements Code
         additionalProperties.put(CodegenConstants.ARTIFACT_VERSION, artifactVersion);
 
         supportingFiles.add(new SupportingFile("index.mustache", "", "index.adoc"));
-        reservedWords = new HashSet<String>();
+        reservedWords = new HashSet<>();
 
-        languageSpecificPrimitives = new HashSet<String>();
+        languageSpecificPrimitives = new HashSet<>();
-        importMapping = new HashMap<String, String>();
+        importMapping = new HashMap<>();
 
     }
 
@@ -325,7 +325,7 @@ public class AsciidocDocumentationCodegen extends DefaultCodegen implements Code
     public void processOpts() {
         super.processOpts();
 
-        String specDir = this.additionalProperties.get(SPEC_DIR) + "";
+        String specDir = String.valueOf(this.additionalProperties.get(SPEC_DIR));
         if (!Files.isDirectory(Paths.get(specDir))) {
             LOGGER.warn("base part for include markup lambda not found: {} as {}", specDir, Paths.get(specDir).toAbsolutePath());
         }
@@ -333,7 +333,7 @@ public class AsciidocDocumentationCodegen extends DefaultCodegen implements Code
         this.includeSpecMarkupLambda = new IncludeMarkupLambda(SPEC_DIR,specDir);
         additionalProperties.put("specinclude", this.includeSpecMarkupLambda);
 
-        String snippetDir = this.additionalProperties.get(SNIPPET_DIR) + "";
+        String snippetDir = String.valueOf(this.additionalProperties.get(SNIPPET_DIR));
         if (!Files.isDirectory(Paths.get(snippetDir))) {
             LOGGER.warn("base part for include markup lambda not found: {} as {}", snippetDir, Paths.get(snippetDir).toAbsolutePath());
         }

modules/openapi-generator/src/main/java/org/openapitools/codegen/languages/AspNetCoreServerCodegen.java

@@ -444,7 +444,7 @@ public class AspNetCoreServerCodegen extends AbstractCSharpCodegen {
         }
 
         // Converts, for example, PUT to HttpPut for controller attributes
-        operation.httpMethod = "Http" + operation.httpMethod.substring(0, 1) + operation.httpMethod.substring(1).toLowerCase(Locale.ROOT);
+        operation.httpMethod = "Http" + operation.httpMethod.charAt(0) + operation.httpMethod.substring(1).toLowerCase(Locale.ROOT);
     }
 
     @Override
@@ -472,7 +472,7 @@ public class AspNetCoreServerCodegen extends AbstractCSharpCodegen {
                             continue;
                         }
 
-                        if(consumesString.toString().equals("")) {
+                        if(consumesString.toString().isEmpty()) {
                             consumesString = new StringBuilder("\"" + consume.get("mediaType") + "\"");
                         }
                         else {
@@ -500,7 +500,7 @@ public class AspNetCoreServerCodegen extends AbstractCSharpCodegen {
                         }
                     }
 
-                    if(!consumesString.toString().equals("")) {
+                    if(!consumesString.toString().isEmpty()) {
                         operation.vendorExtensions.put("x-aspnetcore-consumes", consumesString.toString());
                     }
                 }

modules/openapi-generator/src/main/java/org/openapitools/codegen/languages/BashClientCodegen.java

@@ -209,7 +209,7 @@ public class BashClientCodegen extends DefaultCodegen implements CodegenConfig {
         /**
          * Bash reserved words.
          */
-        reservedWords = new HashSet<String>(
+        reservedWords = new HashSet<>(
                 Arrays.asList(
                         "case",
                         "do",

modules/openapi-generator/src/main/java/org/openapitools/codegen/languages/CLibcurlClientCodegen.java

@@ -874,7 +874,7 @@ public class CLibcurlClientCodegen extends DefaultCodegen implements CodegenConf
         }
 
         // only process the following type (or we can simply rely on the file extension to check if it's a .c or .h file)
-        Set<String> supportedFileType = new HashSet<String>(
+        Set<String> supportedFileType = new HashSet<>(
                 Arrays.asList(
                         "supporting-mustache",
                         "model-test",
@@ -888,7 +888,7 @@ public class CLibcurlClientCodegen extends DefaultCodegen implements CodegenConf
         // only process files with .c or .h extension
         if ("c".equals(FilenameUtils.getExtension(file.toString())) ||
                 "h".equals(FilenameUtils.getExtension(file.toString()))) {
-            String command = cPostProcessFile + " " + file.toString();
+            String command = cPostProcessFile + " " + file;
             try {
                 Process p = Runtime.getRuntime().exec(command);
                 int exitValue = p.waitFor();

modules/openapi-generator/src/main/java/org/openapitools/codegen/languages/CSharpClientCodegen.java

@@ -35,7 +35,7 @@ import static org.openapitools.codegen.utils.StringUtils.camelize;
 import static org.openapitools.codegen.utils.StringUtils.underscore;
 
 public class CSharpClientCodegen extends AbstractCSharpCodegen {
-    @SuppressWarnings({"hiding"})
+    @SuppressWarnings("hiding")
     private final Logger LOGGER = LoggerFactory.getLogger(CSharpClientCodegen.class);
     private static final String NUNIT = "nunit";
     private static final String RESTSHARP = "restsharp";

modules/openapi-generator/src/main/java/org/openapitools/codegen/languages/CSharpNetCoreClientCodegen.java

@@ -56,7 +56,7 @@ public class CSharpNetCoreClientCodegen extends AbstractCSharpCodegen {
     // Project Variable, determined from target framework. Not intended to be user-settable.
     protected static final String TARGET_FRAMEWORK_VERSION = "targetFrameworkVersion";
 
-    @SuppressWarnings({"hiding"})
+    @SuppressWarnings("hiding")
     private final Logger LOGGER = LoggerFactory.getLogger(CSharpClientCodegen.class);
     private static final List<FrameworkStrategy> frameworkStrategies = Arrays.asList(
             FrameworkStrategy.NETSTANDARD_1_3,

modules/openapi-generator/src/main/java/org/openapitools/codegen/languages/ConfluenceWikiCodegen.java

@@ -55,7 +55,7 @@ public class ConfluenceWikiCodegen extends DefaultCodegen implements CodegenConf
         outputFolder = "docs";
         embeddedTemplateDir = templateDir = "confluenceWikiDocs";
 
-        defaultIncludes = new HashSet<String>();
+        defaultIncludes = new HashSet<>();
 
         cliOptions.add(new CliOption("appName", "short name of the application"));
         cliOptions.add(new CliOption("appDescription", "description of the application"));
@@ -80,10 +80,10 @@ public class ConfluenceWikiCodegen extends DefaultCodegen implements CodegenConf
         additionalProperties.put(CodegenConstants.ARTIFACT_VERSION, artifactVersion);
 
         supportingFiles.add(new SupportingFile("index.mustache", "", "confluence-markup.txt"));
-        reservedWords = new HashSet<String>();
+        reservedWords = new HashSet<>();
 
-        languageSpecificPrimitives = new HashSet<String>();
+        languageSpecificPrimitives = new HashSet<>();
-        importMapping = new HashMap<String, String>();
+        importMapping = new HashMap<>();
     }
 
     @Override

modules/openapi-generator/src/main/java/org/openapitools/codegen/languages/CppPistacheServerCodegen.java

@@ -116,10 +116,10 @@ public class CppPistacheServerCodegen extends AbstractCppCodegen {
         supportingFiles.add(new SupportingFile("cmake.mustache", "", "CMakeLists.txt"));
         supportingFiles.add(new SupportingFile("README.mustache", "", "README.md"));
 
-        languageSpecificPrimitives = new HashSet<String>(
+        languageSpecificPrimitives = new HashSet<>(
                 Arrays.asList("int", "char", "bool", "long", "float", "double", "int32_t", "int64_t"));
 
-        typeMapping = new HashMap<String, String>();
+        typeMapping = new HashMap<>();
         typeMapping.put("date", "std::string");
         typeMapping.put("DateTime", "std::string");
         typeMapping.put("string", "std::string");
@@ -137,7 +137,7 @@ public class CppPistacheServerCodegen extends AbstractCppCodegen {
         typeMapping.put("URI", "std::string");
         typeMapping.put("ByteArray", "std::string");
 
-        super.importMapping = new HashMap<String, String>();
+        super.importMapping = new HashMap<>();
         importMapping.put("std::vector", "#include <vector>");
         importMapping.put("std::map", "#include <map>");
         importMapping.put("std::string", "#include <string>");

modules/openapi-generator/src/main/java/org/openapitools/codegen/languages/CppQtAbstractCodegen.java

@@ -22,13 +22,13 @@ public abstract class CppQtAbstractCodegen extends AbstractCppCodegen implements
     protected static final String CPP_NAMESPACE_DESC = "C++ namespace (convention: name::space::for::api).";
     protected static final String CONTENT_COMPRESSION_ENABLED = "contentCompression";
     protected static final String CONTENT_COMPRESSION_ENABLED_DESC = "Enable Compressed Content Encoding for requests and responses";
-    protected Set<String> foundationClasses = new HashSet<String>();
+    protected Set<String> foundationClasses = new HashSet<>();
     protected String cppNamespace = "OpenAPI";
-    protected Map<String, String> namespaces = new HashMap<String, String>();
+    protected Map<String, String> namespaces = new HashMap<>();
-    protected Set<String> systemIncludes = new HashSet<String>();
+    protected Set<String> systemIncludes = new HashSet<>();
     protected boolean isContentCompressionEnabled = false;
 
-    protected Set<String> nonFrameworkPrimitives = new HashSet<String>();
+    protected Set<String> nonFrameworkPrimitives = new HashSet<>();
 
     public CppQtAbstractCodegen() {
         super();
@@ -75,7 +75,7 @@ public abstract class CppQtAbstractCodegen extends AbstractCppCodegen implements
          * Language Specific Primitives.  These types will not trigger imports by
          * the client generator
          */
-        languageSpecificPrimitives = new HashSet<String>(
+        languageSpecificPrimitives = new HashSet<>(
                 Arrays.asList(
                         "bool",
                         "qint32",
@@ -93,7 +93,7 @@ public abstract class CppQtAbstractCodegen extends AbstractCppCodegen implements
                         "QByteArray")
         );
         languageSpecificPrimitives.addAll(foundationClasses);
-        super.typeMapping = new HashMap<String, String>();
+        super.typeMapping = new HashMap<>();
 
         typeMapping.put("date", "QDate");
         typeMapping.put("DateTime", "QDateTime");
@@ -116,8 +116,8 @@ public abstract class CppQtAbstractCodegen extends AbstractCppCodegen implements
         typeMapping.put("URI", "QString");
         typeMapping.put("file", "QByteArray");
         typeMapping.put("binary", "QByteArray");
-        importMapping = new HashMap<String, String>();
+        importMapping = new HashMap<>();
-        namespaces = new HashMap<String, String>();
+        namespaces = new HashMap<>();
 
         systemIncludes.add("QString");
         systemIncludes.add("QList");
@@ -315,7 +315,7 @@ public abstract class CppQtAbstractCodegen extends AbstractCppCodegen implements
         List<CodegenOperation> operations = (List<CodegenOperation>) objectMap.get("operation");
 
         List<Map<String, String>> imports = (List<Map<String, String>>) objs.get("imports");
-        Map<String, CodegenModel> codegenModels = new HashMap<String, CodegenModel>();
+        Map<String, CodegenModel> codegenModels = new HashMap<>();
 
         for (Object moObj : allModels) {
             CodegenModel mo = ((Map<String, CodegenModel>) moObj).get("model");
@@ -336,7 +336,7 @@ public abstract class CppQtAbstractCodegen extends AbstractCppCodegen implements
                     imports.add(createMapping("import", operation.returnBaseType));
                 }
             }
-            List<CodegenParameter> params = new ArrayList<CodegenParameter>();
+            List<CodegenParameter> params = new ArrayList<>();
             if (operation.allParams != null) params.addAll(operation.allParams);
 
             // Check all parameter baseType if there is a necessity to include, include it if not
@@ -375,7 +375,7 @@ public abstract class CppQtAbstractCodegen extends AbstractCppCodegen implements
     }
 
     private Map<String, String> createMapping(String key, String value) {
-        Map<String, String> customImport = new HashMap<String, String>();
+        Map<String, String> customImport = new HashMap<>();
         customImport.put(key, toModelImport(value));
         return customImport;
     }

modules/openapi-generator/src/main/java/org/openapitools/codegen/languages/CppRestSdkClientCodegen.java

@@ -166,10 +166,10 @@ public class CppRestSdkClientCodegen extends AbstractCppCodegen {
         supportingFiles.add(new SupportingFile("cmake-config.mustache", "", "Config.cmake.in"));
         supportingFiles.add(new SupportingFile("README.mustache", "", "README.md"));
 
-        languageSpecificPrimitives = new HashSet<String>(
+        languageSpecificPrimitives = new HashSet<>(
                 Arrays.asList("int", "char", "bool", "long", "float", "double", "int32_t", "int64_t"));
 
-        typeMapping = new HashMap<String, String>();
+        typeMapping = new HashMap<>();
         typeMapping.put("date", "utility::datetime");
         typeMapping.put("DateTime", "utility::datetime");
         typeMapping.put("string", "utility::string_t");
@@ -186,7 +186,7 @@ public class CppRestSdkClientCodegen extends AbstractCppCodegen {
         typeMapping.put("URI", "utility::string_t");
         typeMapping.put("ByteArray", "utility::string_t");
 
-        super.importMapping = new HashMap<String, String>();
+        super.importMapping = new HashMap<>();
         importMapping.put("std::vector", "#include <vector>");
         importMapping.put("std::map", "#include <map>");
         importMapping.put("std::string", "#include <string>");
@@ -263,7 +263,7 @@ public class CppRestSdkClientCodegen extends AbstractCppCodegen {
         CodegenModel codegenModel = super.fromModel(name, model);
 
         Set<String> oldImports = codegenModel.imports;
-        codegenModel.imports = new HashSet<String>();
+        codegenModel.imports = new HashSet<>();
         for (String imp : oldImports) {
             String newImp = toModelImport(imp);
             if (!newImp.isEmpty()) {

modules/openapi-generator/src/main/java/org/openapitools/codegen/languages/CppRestbedServerCodegen.java

@@ -93,10 +93,10 @@ public class CppRestbedServerCodegen extends AbstractCppCodegen {
         supportingFiles.add(new SupportingFile("git_push.sh.mustache", "", "git_push.sh"));
         supportingFiles.add(new SupportingFile("README.mustache", "", "README.md"));
 
-        languageSpecificPrimitives = new HashSet<String>(
+        languageSpecificPrimitives = new HashSet<>(
                 Arrays.asList("int", "char", "bool", "long", "float", "double", "int32_t", "int64_t"));
 
-        typeMapping = new HashMap<String, String>();
+        typeMapping = new HashMap<>();
         typeMapping.put("date", "std::string");
         typeMapping.put("DateTime", "std::string");
         typeMapping.put("string", "std::string");
@@ -113,7 +113,7 @@ public class CppRestbedServerCodegen extends AbstractCppCodegen {
         typeMapping.put("URI", "std::string");
         typeMapping.put("ByteArray", "std::string");
 
-        super.importMapping = new HashMap<String, String>();
+        super.importMapping = new HashMap<>();
         importMapping.put("std::vector", "#include <vector>");
         importMapping.put("std::map", "#include <map>");
         importMapping.put("std::string", "#include <string>");
@@ -129,7 +129,7 @@ public class CppRestbedServerCodegen extends AbstractCppCodegen {
         // Clean interfaces of ambiguity
         for (Entry<String, CodegenModel> cm : allModels.entrySet()) {
             if (cm.getValue().getInterfaces() != null && !cm.getValue().getInterfaces().isEmpty()) {
-                List<String> newIntf = new ArrayList<String>(cm.getValue().getInterfaces());
+                List<String> newIntf = new ArrayList<>(cm.getValue().getInterfaces());
 
                 for (String intf : allModels.get(cm.getKey()).getInterfaces()) {
                     if (allModels.get(intf).getInterfaces() != null && !allModels.get(intf).getInterfaces().isEmpty()) {
@@ -256,7 +256,7 @@ public class CppRestbedServerCodegen extends AbstractCppCodegen {
         CodegenModel codegenModel = super.fromModel(name, model);
 
         Set<String> oldImports = codegenModel.imports;
-        codegenModel.imports = new HashSet<String>();
+        codegenModel.imports = new HashSet<>();
         for (String imp : oldImports) {
             String newImp = toModelImport(imp);
             if (!newImp.isEmpty()) {
@@ -285,7 +285,7 @@ public class CppRestbedServerCodegen extends AbstractCppCodegen {
     public Map<String, Object> postProcessOperationsWithModels(Map<String, Object> objs, List<Object> allModels) {
         Map<String, Object> operations = (Map<String, Object>) objs.get("operations");
         List<CodegenOperation> operationList = (List<CodegenOperation>) operations.get("operation");
-        List<CodegenOperation> newOpList = new ArrayList<CodegenOperation>();
+        List<CodegenOperation> newOpList = new ArrayList<>();
 
         for (CodegenOperation op : operationList) {
             String path = op.path;
@@ -318,7 +318,7 @@ public class CppRestbedServerCodegen extends AbstractCppCodegen {
                         final String X_CODEGEN_OTHER_METHODS = "x-codegen-other-methods";
                         List<CodegenOperation> currentOtherMethodList = (List<CodegenOperation>) op1.vendorExtensions.get(X_CODEGEN_OTHER_METHODS);
                         if (currentOtherMethodList == null) {
-                            currentOtherMethodList = new ArrayList<CodegenOperation>();
+                            currentOtherMethodList = new ArrayList<>();
                         }
                         op.operationIdCamelCase = op1.operationIdCamelCase;
                         currentOtherMethodList.add(op);

modules/openapi-generator/src/main/java/org/openapitools/codegen/languages/CppTinyClientCodegen.java

@@ -71,7 +71,7 @@ public class CppTinyClientCodegen extends AbstractCppCodegen implements CodegenC
     }
 
     public void addControllerToAdditionalProperties() {
-        Map<String, String> supportedControllers = new HashMap<String, String>();
+        Map<String, String> supportedControllers = new HashMap<>();
         supportedControllers.put("esp32", "isESP32");
         supportedControllers.put("esp8266", "isESP8266");
         if (supportedControllers.containsKey(controller)) {
@@ -164,7 +164,7 @@ public class CppTinyClientCodegen extends AbstractCppCodegen implements CodegenC
         supportingFiles.add(new SupportingFile("root.cert.mustache", rootFolder, "root.cert")); // TODO no overwrite
         supportingFiles.add(new SupportingFile("pre_compiling_bourne.py.mustache", rootFolder, "pre_compiling_bourne.py"));
 
-        defaultIncludes = new HashSet<String>(
+        defaultIncludes = new HashSet<>(
                 Arrays.asList(
                         "bool",
                         "int",
@@ -172,7 +172,7 @@ public class CppTinyClientCodegen extends AbstractCppCodegen implements CodegenC
                         "double",
                         "float")
         );
-        languageSpecificPrimitives = new HashSet<String>(
+        languageSpecificPrimitives = new HashSet<>(
                 Arrays.asList(
                         "bool",
                         "int",
@@ -182,7 +182,7 @@ public class CppTinyClientCodegen extends AbstractCppCodegen implements CodegenC
                         "std::string")
         );
 
-        super.typeMapping = new HashMap<String, String>();
+        super.typeMapping = new HashMap<>();
         typeMapping.put("string", "std::string");
         typeMapping.put("integer", "int");
         typeMapping.put("boolean", "bool");
@@ -257,7 +257,7 @@ public class CppTinyClientCodegen extends AbstractCppCodegen implements CodegenC
         if (languageSpecificPrimitives.contains(openAPIType)) {
             return toModelName(openAPIType);
         } else {
-            return openAPIType + "";
+            return openAPIType;
         }
     }
 
@@ -314,7 +314,7 @@ public class CppTinyClientCodegen extends AbstractCppCodegen implements CodegenC
         if (isReservedWord(paramName)) {
             return escapeReservedWord(paramName);
         }
-        return "" + paramName;
+        return paramName;
     }
 
     @Override

modules/openapi-generator/src/main/java/org/openapitools/codegen/languages/CppTizenClientCodegen.java

@@ -71,7 +71,7 @@ public class CppTizenClientCodegen extends AbstractCppCodegen implements Codegen
         embeddedTemplateDir = templateDir = "cpp-tizen-client";
         modelPackage = "";
 
-        defaultIncludes = new HashSet<String>(
+        defaultIncludes = new HashSet<>(
                 Arrays.asList(
                         "bool",
                         "int",
@@ -79,7 +79,7 @@ public class CppTizenClientCodegen extends AbstractCppCodegen implements Codegen
                         "double",
                         "float")
         );
-        languageSpecificPrimitives = new HashSet<String>(
+        languageSpecificPrimitives = new HashSet<>(
                 Arrays.asList(
                         "bool",
                         "int",
@@ -105,7 +105,7 @@ public class CppTizenClientCodegen extends AbstractCppCodegen implements Codegen
                         "unsigned", "using", "virtual", "void", "volatile", "wchar_t", "while", "xor", "xor_eq"
                 ));
 
-        super.typeMapping = new HashMap<String, String>();
+        super.typeMapping = new HashMap<>();
 
         //typeMapping.put("Date", "DateTime");
         //typeMapping.put("DateTime", "DateTime");
@@ -128,7 +128,7 @@ public class CppTizenClientCodegen extends AbstractCppCodegen implements Codegen
         typeMapping.put("UUID", "std::string");
         typeMapping.put("URI", "std::string");
 
-        importMapping = new HashMap<String, String>();
+        importMapping = new HashMap<>();
 
         supportingFiles.clear();
         supportingFiles.add(new SupportingFile("helpers-header.mustache", sourceFolder, "Helpers.h"));
@@ -175,7 +175,7 @@ public class CppTizenClientCodegen extends AbstractCppCodegen implements Codegen
         if (languageSpecificPrimitives.contains(name)) {
             return name;
         } else {
-            return name + "";
+            return name;
         }
     }
 
@@ -200,7 +200,7 @@ public class CppTizenClientCodegen extends AbstractCppCodegen implements Codegen
         if (languageSpecificPrimitives.contains(openAPIType)) {
             return toModelName(openAPIType);
         } else {
-            return openAPIType + "";
+            return openAPIType;
         }
     }
 
@@ -295,7 +295,7 @@ public class CppTizenClientCodegen extends AbstractCppCodegen implements Codegen
         if (isReservedWord(paramName)) {
             return escapeReservedWord(paramName);
         }
-        return "" + paramName;
+        return paramName;
     }
 
     @Override

modules/openapi-generator/src/main/java/org/openapitools/codegen/languages/CppUE4ClientCodegen.java

@@ -39,14 +39,14 @@ public class CppUE4ClientCodegen extends AbstractCppCodegen {
 
     protected String unrealModuleName = "OpenAPI";
     // Will be treated as pointer
-    protected Set<String> pointerClasses = new HashSet<String>();
+    protected Set<String> pointerClasses = new HashSet<>();
     // source folder where to write the files
     protected String privateFolder = "Private";
     protected String publicFolder = "Public";
     protected String apiVersion = "1.0.0";
-    protected Map<String, String> namespaces = new HashMap<String, String>();
+    protected Map<String, String> namespaces = new HashMap<>();
     // Will be included using the <> syntax, not used in Unreal's coding convention
-    protected Set<String> systemIncludes = new HashSet<String>();
+    protected Set<String> systemIncludes = new HashSet<>();
     protected String cppNamespace = unrealModuleName;
     protected boolean optionalProjectFileFlag = true;
 
@@ -132,7 +132,7 @@ public class CppUE4ClientCodegen extends AbstractCppCodegen {
          * Language Specific Primitives.  These types will not trigger imports by
          * the client generator
          */
-        languageSpecificPrimitives = new HashSet<String>(
+        languageSpecificPrimitives = new HashSet<>(
                 Arrays.asList(
                         "bool",
                         "int32",
@@ -159,7 +159,7 @@ public class CppUE4ClientCodegen extends AbstractCppCodegen {
             supportingFiles.add(new SupportingFile("module-source.mustache", privateFolder, unrealModuleName + "Module.cpp"));
         }
 
-        super.typeMapping = new HashMap<String, String>();
+        super.typeMapping = new HashMap<>();
 
         // Maps C++ types during call to getSchemaType, see DefaultCodegen.getSchemaType and not the types/formats
         // defined in openapi specification "array" is also used explicitly in the generator for containers
@@ -188,10 +188,10 @@ public class CppUE4ClientCodegen extends AbstractCppCodegen {
         typeMapping.put("UUID", "FGuid");
         typeMapping.put("AnyType", "TSharedPtr<FJsonValue>");
 
-        importMapping = new HashMap<String, String>();
+        importMapping = new HashMap<>();
         importMapping.put("HttpFileInput", "#include \"" + modelNamePrefix + "Helpers.h\"");
 
-        namespaces = new HashMap<String, String>();
+        namespaces = new HashMap<>();
     }
 
     @Override

modules/openapi-generator/src/main/java/org/openapitools/codegen/languages/CrystalClientCodegen.java

@@ -130,7 +130,7 @@ public class CrystalClientCodegen extends DefaultCodegen {
         hideGenerationTimestamp = Boolean.TRUE;
 
         // reserved word. Ref: https://github.com/crystal-lang/crystal/wiki/Crystal-for-Rubyists#available-keywords
-        reservedWords = new HashSet<String>(
+        reservedWords = new HashSet<>(
                 Arrays.asList(
                         "abstract", "do", "if", "nil?", "select", "union",
                         "alias", "else", "in", "of", "self", "unless",
@@ -557,8 +557,8 @@ public class CrystalClientCodegen extends DefaultCodegen {
     public Map<String, Object> postProcessOperationsWithModels(Map<String, Object> objs, List<Object> allModels) {
         objs = super.postProcessOperationsWithModels(objs, allModels);
         Map<String, Object> operations = (Map<String, Object>) objs.get("operations");
-        HashMap<String, CodegenModel> modelMaps = new HashMap<String, CodegenModel>();
+        HashMap<String, CodegenModel> modelMaps = new HashMap<>();
-        HashMap<String, Integer> processedModelMaps = new HashMap<String, Integer>();
+        HashMap<String, Integer> processedModelMaps = new HashMap<>();
 
         for (Object o : allModels) {
             HashMap<String, Object> h = (HashMap<String, Object>) o;
@@ -870,7 +870,7 @@ public class CrystalClientCodegen extends DefaultCodegen {
         }
         // only process files with cr extension
         if ("cr".equals(FilenameUtils.getExtension(file.toString()))) {
-            String command = crystalPostProcessFile + " " + file.toString();
+            String command = crystalPostProcessFile + " " + file;
             try {
                 Process p = Runtime.getRuntime().exec(command);
                 int exitValue = p.waitFor();
@@ -882,7 +882,7 @@ public class CrystalClientCodegen extends DefaultCodegen {
                         while ((line = br.readLine()) != null) {
                             sb.append(line);
                         }
-                        LOGGER.error("Error running the command ({}). Exit value: {}, Error output: {}", command, exitValue, sb.toString());
+                        LOGGER.error("Error running the command ({}). Exit value: {}, Error output: {}", command, exitValue, sb);
                     }
                 } else {
                     LOGGER.info("Successfully executed: {}", command);

modules/openapi-generator/src/main/java/org/openapitools/codegen/languages/ElixirClientCodegen.java

@@ -116,7 +116,7 @@ public class ElixirClientCodegen extends DefaultCodegen implements CodegenConfig
          * Reserved words.  Override this with reserved words specific to your language
          * Ref: https://github.com/itsgreggreg/elixir_quick_reference#reserved-words
          */
-        reservedWords = new HashSet<String>(
+        reservedWords = new HashSet<>(
                 Arrays.asList(
                         "nil",
                         "true",
@@ -164,7 +164,7 @@ public class ElixirClientCodegen extends DefaultCodegen implements CodegenConfig
          * Language Specific Primitives.  These types will not trigger imports by
          * the client generator
          */
-        languageSpecificPrimitives = new HashSet<String>(
+        languageSpecificPrimitives = new HashSet<>(
                 Arrays.asList(
                         "Integer",
                         "Float",
@@ -182,7 +182,7 @@ public class ElixirClientCodegen extends DefaultCodegen implements CodegenConfig
         );
 
         // ref: https://github.com/OAI/OpenAPI-Specification/blob/master/versions/2.0.md#data-types
-        typeMapping = new HashMap<String, String>();
+        typeMapping = new HashMap<>();
         typeMapping.put("integer", "Integer");
         typeMapping.put("long", "Integer");
         typeMapping.put("number", "Float");
@@ -727,10 +727,10 @@ public class ElixirClientCodegen extends DefaultCodegen implements CodegenConfig
             }
 
             sb.append("keyword()) :: ");
-            HashSet<String> uniqueResponseTypes = new HashSet<String>();
+            HashSet<String> uniqueResponseTypes = new HashSet<>();
             for (CodegenResponse response : this.responses) {
                 ExtendedCodegenResponse exResponse = (ExtendedCodegenResponse) response;
-                StringBuilder returnEntry = new StringBuilder("");
+                StringBuilder returnEntry = new StringBuilder();
                 if (exResponse.baseType == null) {
                     returnEntry.append("nil");
                 } else if (exResponse.simpleType) {

modules/openapi-generator/src/main/java/org/openapitools/codegen/languages/ElmClientCodegen.java

@@ -328,19 +328,17 @@ public class ElmClientCodegen extends DefaultCodegen implements CodegenConfig {
 
     private boolean anyVarMatches(final List<Map<String, Object>> models, final Predicate<CodegenProperty> predicate) {
         return models.stream()
-            .map(obj -> (CodegenModel) obj.get("model"))
+                .map(obj -> (CodegenModel) obj.get("model"))
-            .flatMap(model -> model.vars.stream())
+                .flatMap(model -> model.vars.stream()).anyMatch(var -> {
-            .filter(var -> {
+                    CodegenProperty prop = var;
-                CodegenProperty prop = var;
+                    while (prop != null) {
-                while (prop != null) {
+                        if (predicate.test(prop)) {
-                    if (predicate.test(prop)) {
+                            return true;
-                        return true;
+                        }
+                        prop = prop.items;
                     }
-                    prop = prop.items;
+                    return false;
-                }
+                });
-                return false;
-            })
-            .count() > 0;
     }
 
     @Override

modules/openapi-generator/src/main/java/org/openapitools/codegen/languages/FsharpGiraffeServerCodegen.java

@@ -267,7 +267,7 @@ public class FsharpGiraffeServerCodegen extends AbstractFSharpCodegen {
         }
 
         // Converts, for example, PUT to HttpPut for controller attributes
-        operation.httpMethod = "Http" + operation.httpMethod.substring(0, 1) + operation.httpMethod.substring(1).toLowerCase(Locale.ROOT);
+        operation.httpMethod = "Http" + operation.httpMethod.charAt(0) + operation.httpMethod.substring(1).toLowerCase(Locale.ROOT);
     }
 
     @Override

modules/openapi-generator/src/main/java/org/openapitools/codegen/languages/HaskellHttpClientCodegen.java

@@ -136,8 +136,8 @@ public class HaskellHttpClientCodegen extends DefaultCodegen implements CodegenC
     protected Map<String, Map<String, Object>> uniqueParamNameTypes = new HashMap<>();
     protected Map<String, Set<String>> modelMimeTypes = new HashMap<>();
     protected Map<String, String> knownMimeDataTypes = new HashMap<>();
-    protected Set<String> typeNames = new HashSet<String>();
+    protected Set<String> typeNames = new HashSet<>();
-    protected Set<String> modelTypeNames = new HashSet<String>();
+    protected Set<String> modelTypeNames = new HashSet<>();
 
     final private static Pattern CONTAINS_JSON_MIME_PATTERN = Pattern.compile("(?i)application/.*json(;.*)?");
 
@@ -235,7 +235,7 @@ public class HaskellHttpClientCodegen extends DefaultCodegen implements CodegenC
         supportingFiles.add(new SupportingFile("tests/PropMime.mustache", "tests", "PropMime.hs"));
         supportingFiles.add(new SupportingFile("tests/Test.mustache", "tests", "Test.hs"));
 
-        languageSpecificPrimitives = new HashSet<String>(
+        languageSpecificPrimitives = new HashSet<>(
                 Arrays.asList(
                         "Bool",
                         "String",
@@ -555,7 +555,7 @@ public class HaskellHttpClientCodegen extends DefaultCodegen implements CodegenC
         }
 
         if (!additionalProperties.containsKey(PROP_BASE_MODULE)) {
-            List<String> wordsCaps = new ArrayList<String>();
+            List<String> wordsCaps = new ArrayList<>();
             for (String word : baseTitle.split(" ")) {
                 wordsCaps.add(firstLetterToUpper(word));
             }
@@ -684,7 +684,7 @@ public class HaskellHttpClientCodegen extends DefaultCodegen implements CodegenC
     public void addOperationToGroup(String tag, String resourcePath, Operation operation, CodegenOperation op, Map<String, List<CodegenOperation>> operations) {
         List<CodegenOperation> opList = operations.get(tag);
         if (opList == null || opList.isEmpty()) {
-            opList = new ArrayList<CodegenOperation>();
+            opList = new ArrayList<>();
             operations.put(tag, opList);
         }
         // check for operationId uniqueness
@@ -1454,7 +1454,7 @@ public class HaskellHttpClientCodegen extends DefaultCodegen implements CodegenC
 
         // only process files with hs extension
         if ("hs".equals(FilenameUtils.getExtension(file.toString()))) {
-            String command = haskellPostProcessFile + " " + file.toString();
+            String command = haskellPostProcessFile + " " + file;
             try {
                 Process p = Runtime.getRuntime().exec(command);
                 int exitValue = p.waitFor();

modules/openapi-generator/src/main/java/org/openapitools/codegen/languages/HaskellServantCodegen.java

@@ -169,7 +169,7 @@ public class HaskellServantCodegen extends DefaultCodegen implements CodegenConf
          * Language Specific Primitives.  These types will not trigger imports by
          * the client generator
          */
-        languageSpecificPrimitives = new HashSet<String>(
+        languageSpecificPrimitives = new HashSet<>(
                 Arrays.asList(
                         "Bool",
                         "String",
@@ -286,14 +286,14 @@ public class HaskellServantCodegen extends DefaultCodegen implements CodegenConf
         String[] words = title.split(" ");
 
         // The package name is made by appending the lowercased words of the title interspersed with dashes
-        List<String> wordsLower = new ArrayList<String>();
+        List<String> wordsLower = new ArrayList<>();
         for (String word : words) {
             wordsLower.add(word.toLowerCase(Locale.ROOT));
         }
         String cabalName = joinStrings("-", wordsLower);
 
         // The API name is made by appending the capitalized words of the title
-        List<String> wordsCaps = new ArrayList<String>();
+        List<String> wordsCaps = new ArrayList<>();
         for (String word : words) {
             wordsCaps.add(firstLetterToUpper(word));
         }
@@ -446,7 +446,7 @@ public class HaskellServantCodegen extends DefaultCodegen implements CodegenConf
     // IdType is provided by the capture params.
     private List<String> pathToServantRoute(String path, List<CodegenParameter> pathParams) {
         // Map the capture params by their names.
-        HashMap<String, String> captureTypes = new HashMap<String, String>();
+        HashMap<String, String> captureTypes = new HashMap<>();
         for (CodegenParameter param : pathParams) {
             captureTypes.put(param.baseName, param.dataType);
         }
@@ -462,7 +462,7 @@ public class HaskellServantCodegen extends DefaultCodegen implements CodegenConf
         }
 
         // Convert the path into a list of servant route components.
-        List<String> pathComponents = new ArrayList<String>();
+        List<String> pathComponents = new ArrayList<>();
         for (String piece : path.split("/")) {
             if (piece.startsWith("{") && piece.endsWith("}")) {
                 String name = piece.substring(1, piece.length() - 1);
@@ -479,7 +479,7 @@ public class HaskellServantCodegen extends DefaultCodegen implements CodegenConf
     // Extract the arguments that are passed in the route path parameters
     private List<String> pathToClientType(String path, List<CodegenParameter> pathParams) {
         // Map the capture params by their names.
-        HashMap<String, String> captureTypes = new HashMap<String, String>();
+        HashMap<String, String> captureTypes = new HashMap<>();
         for (CodegenParameter param : pathParams) {
             captureTypes.put(param.baseName, param.dataType);
         }
@@ -490,7 +490,7 @@ public class HaskellServantCodegen extends DefaultCodegen implements CodegenConf
         }
 
         // Convert the path into a list of servant route components.
-        List<String> type = new ArrayList<String>();
+        List<String> type = new ArrayList<>();
         for (String piece : path.split("/")) {
             if (piece.startsWith("{") && piece.endsWith("}")) {
                 String name = piece.substring(1, piece.length() - 1);
@@ -605,8 +605,8 @@ public class HaskellServantCodegen extends DefaultCodegen implements CodegenConf
         String name = string;
         //Check if it is a reserved word, in which case the underscore is added when property name is generated.
         if (string.startsWith("_")) {
-            if (reservedWords.contains(string.substring(1, string.length()))) {
+            if (reservedWords.contains(string.substring(1))) {
-                name = string.substring(1, string.length());
+                name = string.substring(1);
             } else if (reservedWordsMappings.containsValue(string)) {
                 name = LEADING_UNDERSCORE.matcher(string).replaceFirst("");
             }
@@ -685,7 +685,7 @@ public class HaskellServantCodegen extends DefaultCodegen implements CodegenConf
 
         // only process files with hs extension
         if ("hs".equals(FilenameUtils.getExtension(file.toString()))) {
-            String command = haskellPostProcessFile + " " + file.toString();
+            String command = haskellPostProcessFile + " " + file;
             try {
                 Process p = Runtime.getRuntime().exec(command);
                 int exitValue = p.waitFor();

modules/openapi-generator/src/main/java/org/openapitools/codegen/languages/HaskellYesodServerCodegen.java

@@ -136,7 +136,7 @@ public class HaskellYesodServerCodegen extends DefaultCodegen implements Codegen
                 )
         );
 
-        languageSpecificPrimitives = new HashSet<String>(
+        languageSpecificPrimitives = new HashSet<>(
                 Arrays.asList(
                         "Bool",
                         "Int",
@@ -359,7 +359,7 @@ public class HaskellYesodServerCodegen extends DefaultCodegen implements Codegen
 
     private List<String> pathToComponents(String path, List<CodegenParameter> pathParams) {
         // Map the capture params by their names.
-        HashMap<String, String> captureTypes = new HashMap<String, String>();
+        HashMap<String, String> captureTypes = new HashMap<>();
         for (CodegenParameter param : pathParams) {
             captureTypes.put(param.baseName, param.dataType);
         }
@@ -370,7 +370,7 @@ public class HaskellYesodServerCodegen extends DefaultCodegen implements Codegen
         }
 
         // Convert the path into a list of yesod path components.
-        List<String> components = new ArrayList<String>();
+        List<String> components = new ArrayList<>();
         for (String piece : path.split("/")) {
             if (piece.startsWith("{") && piece.endsWith("}")) {
                 String name = piece.substring(1, piece.length() - 1);
@@ -412,7 +412,7 @@ public class HaskellYesodServerCodegen extends DefaultCodegen implements Codegen
 
         List<Map<String, Object>> routes = (List<Map<String, Object>>) additionalProperties.get("routes");
         if (routes == null) {
-            routes = new ArrayList<Map<String, Object>>();
+            routes = new ArrayList<>();
             additionalProperties.put("routes", routes);
         }
 
@@ -432,10 +432,10 @@ public class HaskellYesodServerCodegen extends DefaultCodegen implements Codegen
         }
 
         if (!found) {
-            Map<String, Object> route = new HashMap<String, Object>();
+            Map<String, Object> route = new HashMap<>();
             route.put("path", path);
             route.put("resource", resource);
-            List<String> methods = new ArrayList<String>();
+            List<String> methods = new ArrayList<>();
             methods.add(op.httpMethod);
             route.put("methods", methods);
             routes.add(route);
@@ -534,8 +534,8 @@ public class HaskellYesodServerCodegen extends DefaultCodegen implements Codegen
         String name = string;
         //Check if it is a reserved word, in which case the underscore is added when property name is generated.
         if (string.startsWith("_")) {
-            if (reservedWords.contains(string.substring(1, string.length()))) {
+            if (reservedWords.contains(string.substring(1))) {
-                name = string.substring(1, string.length());
+                name = string.substring(1);
             } else if (reservedWordsMappings.containsValue(string)) {
                 name = LEADING_UNDERSCORE.matcher(string).replaceFirst("");
             }
@@ -614,7 +614,7 @@ public class HaskellYesodServerCodegen extends DefaultCodegen implements Codegen
 
         // only process files with hs extension
         if ("hs".equals(FilenameUtils.getExtension(file.toString()))) {
-            String command = haskellPostProcessFile + " " + file.toString();
+            String command = haskellPostProcessFile + " " + file;
             try {
                 Process p = Runtime.getRuntime().exec(command);
                 int exitValue = p.waitFor();

modules/openapi-generator/src/main/java/org/openapitools/codegen/languages/JMeterClientCodegen.java

@@ -133,7 +133,7 @@ public class JMeterClientCodegen extends DefaultCodegen implements CodegenConfig
         /*
          * Reserved words.  Override this with reserved words specific to your language
          */
-        reservedWords = new HashSet<String>(
+        reservedWords = new HashSet<>(
                 Arrays.asList(
                         "sample1",  // replace with static values
                         "sample2")

modules/openapi-generator/src/main/java/org/openapitools/codegen/languages/JavaCXFClientCodegen.java

@@ -70,7 +70,7 @@ public class JavaCXFClientCodegen extends AbstractJavaCodegen
         updateOption(CodegenConstants.ARTIFACT_ID, this.getArtifactId());
         updateOption(CodegenConstants.API_PACKAGE, apiPackage);
         updateOption(CodegenConstants.MODEL_PACKAGE, modelPackage);
-        updateOption(this.DATE_LIBRARY, this.getDateLibrary());
+        updateOption(DATE_LIBRARY, this.getDateLibrary());
 
         // clear model and api doc template as this codegen
         // does not support auto-generated markdown doc at the moment

modules/openapi-generator/src/main/java/org/openapitools/codegen/languages/JavaCXFExtServerCodegen.java

@@ -655,7 +655,7 @@ public class JavaCXFExtServerCodegen extends JavaCXFServerCodegen implements CXF
                     var.addTestData(randomBigDecimal);
                 }
             } else {
-                buffer.append(randomBigDecimal.toString()).append('D');
+                buffer.append(randomBigDecimal).append('D');
             }
         }
     }
@@ -1294,7 +1294,7 @@ public class JavaCXFExtServerCodegen extends JavaCXFServerCodegen implements CXF
                 if (testDataCache.root().isDirty()) {
                     ByteArrayOutputStream out = new ByteArrayOutputStream();
                     testDataCache.root().flush(out);
-                    String testDataJson = new String(out.toByteArray(), "UTF-8");
+                    String testDataJson = out.toString("UTF-8");
                     objs.put("test-data.json", testDataJson);
                     supportingFiles.add(new SupportingFile("testData.mustache", testDataFile.getAbsolutePath()));
                 }
@@ -1306,7 +1306,7 @@ public class JavaCXFExtServerCodegen extends JavaCXFServerCodegen implements CXF
                 if (testDataControlCache.root().isDirty()) {
                     ByteArrayOutputStream out = new ByteArrayOutputStream();
                     testDataControlCache.root().flush(out);
-                    String testDataControlJson = new String(out.toByteArray(), "UTF-8");
+                    String testDataControlJson = out.toString("UTF-8");
                     objs.put("test-data-control.json", testDataControlJson);
                     supportingFiles
                             .add(new SupportingFile("testDataControl.mustache", testDataControlFile.getAbsolutePath()));

modules/openapi-generator/src/main/java/org/openapitools/codegen/languages/JavaInflectorServerCodegen.java

@@ -65,7 +65,7 @@ public class JavaInflectorServerCodegen extends AbstractJavaCodegen {
         updateOption(CodegenConstants.ARTIFACT_ID, this.getArtifactId());
         updateOption(CodegenConstants.API_PACKAGE, apiPackage);
         updateOption(CodegenConstants.MODEL_PACKAGE, modelPackage);
-        updateOption(this.DATE_LIBRARY, this.getDateLibrary());
+        updateOption(DATE_LIBRARY, this.getDateLibrary());
 
         additionalProperties.put("title", title);
         // java inflector uses the jackson lib

modules/openapi-generator/src/main/java/org/openapitools/codegen/languages/JavaMicronautClientCodegen.java

@@ -116,7 +116,7 @@ public class JavaMicronautClientCodegen extends AbstractJavaCodegen implements B
                 .ifPresent(v -> cliOptions.remove(v));
 
         // Add reserved words
-        String[] reservedWordsArray = new String[]{
+        String[] reservedWordsArray = {
                 "client", "format", "queryvalue", "queryparam", "pathvariable", "header", "cookie",
                 "authorization", "body", "application"
         };

modules/openapi-generator/src/main/java/org/openapitools/codegen/languages/JavaPKMSTServerCodegen.java

@@ -471,7 +471,7 @@ public class JavaPKMSTServerCodegen extends AbstractJavaCodegen {
         // get vendor extensions
 
         Map<String, Object> vendorExt = openAPI.getInfo().getExtensions();
-        if (vendorExt != null && !vendorExt.toString().equals("")) {
+        if (vendorExt != null && !vendorExt.toString().isEmpty()) {
             if (vendorExt.containsKey("x-codegen")) {
 
                 Map<String, String> uris = (Map<String, String>) vendorExt.get("x-codegen");

modules/openapi-generator/src/main/java/org/openapitools/codegen/languages/JavaUndertowServerCodegen.java

@@ -52,7 +52,7 @@ public class JavaUndertowServerCodegen extends AbstractJavaCodegen {
         // clioOptions default redefinition need to be updated
         updateOption(CodegenConstants.INVOKER_PACKAGE, this.getInvokerPackage());
         updateOption(CodegenConstants.ARTIFACT_ID, this.getArtifactId());
-        updateOption(this.DATE_LIBRARY, this.getDateLibrary());
+        updateOption(DATE_LIBRARY, this.getDateLibrary());
 
         apiTestTemplateFiles.clear(); // TODO: add test template
 

modules/openapi-generator/src/main/java/org/openapitools/codegen/languages/JavaVertXServerCodegen.java

@@ -95,7 +95,7 @@ public class JavaVertXServerCodegen extends AbstractJavaCodegen {
         updateOption(CodegenConstants.ARTIFACT_VERSION, this.getArtifactVersion());
         updateOption(CodegenConstants.API_PACKAGE, apiPackage);
         updateOption(CodegenConstants.MODEL_PACKAGE, modelPackage);
-        updateOption(this.DATE_LIBRARY, this.getDateLibrary());
+        updateOption(DATE_LIBRARY, this.getDateLibrary());
 
         additionalProperties.put(ROOT_PACKAGE, rootPackage);
 

modules/openapi-generator/src/main/java/org/openapitools/codegen/languages/JavascriptApolloClientCodegen.java

@@ -49,7 +49,7 @@ public class JavascriptApolloClientCodegen extends DefaultCodegen implements Cod
     public static final String EMIT_JS_DOC = "emitJSDoc";
     public static final String NPM_REPOSITORY = "npmRepository";
 
-    final String[][] JAVASCRIPT_SUPPORTING_FILES = new String[][]{
+    final String[][] JAVASCRIPT_SUPPORTING_FILES = {
             new String[]{"package.mustache", "package.json"},
             // new String[]{"index.mustache", "src/index.js", },
             // new String[]{"ApiClient.mustache", "src/ApiClient.js"},
@@ -59,7 +59,7 @@ public class JavascriptApolloClientCodegen extends DefaultCodegen implements Cod
             new String[]{"travis.yml", ".travis.yml"}
     };
 
-    final String[][] JAVASCRIPT_ES6_SUPPORTING_FILES = new String[][]{
+    final String[][] JAVASCRIPT_ES6_SUPPORTING_FILES = {
             new String[]{"package.mustache", "package.json"},
             // new String[]{"index.mustache", "src/index.js"},
             // new String[]{"ApiClient.mustache", "src/ApiClient.js"},
@@ -132,10 +132,10 @@ public class JavascriptApolloClientCodegen extends DefaultCodegen implements Cod
                         "prototype", "String", "toString", "undefined", "valueOf")
         );
 
-        languageSpecificPrimitives = new HashSet<String>(
+        languageSpecificPrimitives = new HashSet<>(
                 Arrays.asList("String", "Boolean", "Number", "Array", "Object", "Date", "File", "Blob")
         );
-        defaultIncludes = new HashSet<String>(languageSpecificPrimitives);
+        defaultIncludes = new HashSet<>(languageSpecificPrimitives);
 
         instantiationTypes.put("array", "Array");
         instantiationTypes.put("list", "Array");
@@ -1127,7 +1127,7 @@ public class JavascriptApolloClientCodegen extends DefaultCodegen implements Cod
 
         // only process files with js extension
         if ("js".equals(FilenameUtils.getExtension(file.toString()))) {
-            String command = jsPostProcessFile + " " + file.toString();
+            String command = jsPostProcessFile + " " + file;
             try {
                 Process p = Runtime.getRuntime().exec(command);
                 p.waitFor();

modules/openapi-generator/src/main/java/org/openapitools/codegen/languages/JavascriptClientCodegen.java

@@ -51,7 +51,7 @@ public class JavascriptClientCodegen extends DefaultCodegen implements CodegenCo
     public static final String USE_ES6 = "useES6";
     public static final String NPM_REPOSITORY = "npmRepository";
 
-    final String[][] JAVASCRIPT_SUPPORTING_FILES = new String[][]{
+    final String[][] JAVASCRIPT_SUPPORTING_FILES = {
             new String[]{"package.mustache", "package.json"},
             // new String[]{"index.mustache", "src/index.js", },
             // new String[]{"ApiClient.mustache", "src/ApiClient.js"},
@@ -62,7 +62,7 @@ public class JavascriptClientCodegen extends DefaultCodegen implements CodegenCo
             new String[]{"gitignore.mustache", ".gitignore"}
     };
 
-    final String[][] JAVASCRIPT_ES6_SUPPORTING_FILES = new String[][]{
+    final String[][] JAVASCRIPT_ES6_SUPPORTING_FILES = {
             new String[]{"package.mustache", "package.json"},
             // new String[]{"index.mustache", "src/index.js"},
             // new String[]{"ApiClient.mustache", "src/ApiClient.js"},
@@ -135,10 +135,10 @@ public class JavascriptClientCodegen extends DefaultCodegen implements CodegenCo
                         "prototype", "String", "toString", "undefined", "valueOf")
         );
 
-        languageSpecificPrimitives = new HashSet<String>(
+        languageSpecificPrimitives = new HashSet<>(
                 Arrays.asList("String", "Boolean", "Number", "Array", "Object", "Date", "File", "Blob")
         );
-        defaultIncludes = new HashSet<String>(languageSpecificPrimitives);
+        defaultIncludes = new HashSet<>(languageSpecificPrimitives);
 
         instantiationTypes.put("array", "Array");
         instantiationTypes.put("set", "Array");
@@ -1212,7 +1212,7 @@ public class JavascriptClientCodegen extends DefaultCodegen implements CodegenCo
 
         // only process files with js extension
         if ("js".equals(FilenameUtils.getExtension(file.toString()))) {
-            String command = jsPostProcessFile + " " + file.toString();
+            String command = jsPostProcessFile + " " + file;
             try {
                 Process p = Runtime.getRuntime().exec(command);
                 p.waitFor();

modules/openapi-generator/src/main/java/org/openapitools/codegen/languages/JavascriptClosureAngularClientCodegen.java

@@ -55,16 +55,16 @@ public class JavascriptClosureAngularClientCodegen extends DefaultCodegen implem
             "short", "try", "char", "final", "interface", "static", "void",
             "class", "finally", "const", "super", "while"));
 
-        languageSpecificPrimitives = new HashSet<String>(Arrays.asList(
+        languageSpecificPrimitives = new HashSet<>(Arrays.asList(
-            "string",
+                "string",
-            "boolean",
+                "boolean",
-            "number",
+                "number",
-            "Object",
+                "Object",
-            "Blob",
+                "Blob",
-            "Date"));
+                "Date"));
         instantiationTypes.put("array", "Array");
 
-        typeMapping = new HashMap<String, String>();
+        typeMapping = new HashMap<>();
         typeMapping.put("Array", "Array");
         typeMapping.put("array", "Array");
         typeMapping.put("List", "Array");
@@ -86,11 +86,11 @@ public class JavascriptClosureAngularClientCodegen extends DefaultCodegen implem
         typeMapping.put("map", "Object");
         typeMapping.put("DateTime", "Date");
 
-        importMapping = new HashMap<String, String>();
+        importMapping = new HashMap<>();
-        defaultIncludes = new HashSet<String>(Arrays.asList(
+        defaultIncludes = new HashSet<>(Arrays.asList(
-            "Object",
+                "Object",
-            "Array",
+                "Array",
-            "Blob"
+                "Blob"
         ));
 
         typeMapping.put("binary", "string");

modules/openapi-generator/src/main/java/org/openapitools/codegen/languages/JavascriptFlowtypedClientCodegen.java

@@ -64,7 +64,7 @@ public class JavascriptFlowtypedClientCodegen extends AbstractTypeScriptClientCo
                 "Math", "NaN", "Number", "Object",
                 "prototype", "String", "toString", "undefined", "valueOf"));
 
-        languageSpecificPrimitives = new HashSet<String>(
+        languageSpecificPrimitives = new HashSet<>(
                 Arrays.asList("string", "boolean", "number", "Array", "Object", "Date", "File", "Blob")
         );
 
@@ -95,7 +95,7 @@ public class JavascriptFlowtypedClientCodegen extends AbstractTypeScriptClientCo
         typeMapping.put("UUID", "string");
         typeMapping.put("URI", "string");
 
-        defaultIncludes = new HashSet<String>(languageSpecificPrimitives);
+        defaultIncludes = new HashSet<>(languageSpecificPrimitives);
         outputFolder = "generated-code/javascript-flowtyped";
         embeddedTemplateDir = templateDir = "Javascript-Flowtyped";
 
@@ -173,14 +173,14 @@ public class JavascriptFlowtypedClientCodegen extends AbstractTypeScriptClientCo
             // name enum with model name, e.g. StatusEnum => Pet.StatusEnum
             for (CodegenProperty var : cm.vars) {
                 if (Boolean.TRUE.equals(var.isEnum)) {
-                    var.datatypeWithEnum = var.datatypeWithEnum.replace(var.enumName, cm.classname + "" + var.enumName);
+                    var.datatypeWithEnum = var.datatypeWithEnum.replace(var.enumName, cm.classname + var.enumName);
                 }
             }
             if (cm.parent != null) {
                 for (CodegenProperty var : cm.allVars) {
                     if (Boolean.TRUE.equals(var.isEnum)) {
                         var.datatypeWithEnum = var.datatypeWithEnum
-                                .replace(var.enumName, cm.classname + "" + var.enumName);
+                                .replace(var.enumName, cm.classname + var.enumName);
                     }
                 }
             }

modules/openapi-generator/src/main/java/org/openapitools/codegen/languages/K6ClientCodegen.java

@@ -141,7 +141,7 @@ public class K6ClientCodegen extends DefaultCodegen implements CodegenConfig {
                             .map(x -> quoteExample(
                                     StringEscapeUtils.escapeEcmaScript(
                                             String.valueOf(x.getValue()))))
-                            .collect(Collectors.toCollection(() -> new TreeSet<String>()));
+                            .collect(Collectors.toCollection(() -> new TreeSet<>()));
 
                     if (!exampleValues.isEmpty()) {
 
@@ -274,7 +274,7 @@ public class K6ClientCodegen extends DefaultCodegen implements CodegenConfig {
     public static final String BASE_URL = "baseURL";
     public static final String PRESERVE_LEADING_PARAM_CHAR = "preserveLeadingParamChar";
     static final Collection<String> INVOKER_PKG_SUPPORTING_FILES = Arrays.asList("script.mustache", "README.mustache");
-    static final String[][] JAVASCRIPT_SUPPORTING_FILES = new String[][]{
+    static final String[][] JAVASCRIPT_SUPPORTING_FILES = {
             new String[]{"script.mustache", "script.js"}, new String[]{"README.mustache", "README.md"}};
 
     protected String projectName;
@@ -412,7 +412,7 @@ public class K6ClientCodegen extends DefaultCodegen implements CodegenConfig {
                 List<Parameter> queryParams = new ArrayList<>();
                 List<Parameter> bodyOrFormParams = new ArrayList<>();
                 List<k6Check> k6Checks = new ArrayList<>();
-                Set<String> imports = new HashSet<String>();
+                Set<String> imports = new HashSet<>();
 
                 final Operation operation = methodOperation.getValue();
                 final PathItem.HttpMethod method = methodOperation.getKey();

modules/openapi-generator/src/main/java/org/openapitools/codegen/languages/KotlinSpringServerCodegen.java

@@ -454,7 +454,7 @@ public class KotlinSpringServerCodegen extends AbstractKotlinCodegen
                 basePath = basePath.substring(0, pos);
             }
 
-            if (basePath.equals("")) {
+            if (basePath.isEmpty()) {
                 basePath = "default";
             } else {
                 co.subresourceOperation = !co.path.isEmpty();

modules/openapi-generator/src/main/java/org/openapitools/codegen/languages/KtormSchemaCodegen.java

@@ -1055,7 +1055,7 @@ public class KtormSchemaCodegen extends AbstractKotlinCodegen {
 
         // identifier name cannot be empty
         if (escapedName.isEmpty()) {
-            throw new RuntimeException("Empty database/table/column name for property '" + name.toString() + "' not allowed");
+            throw new RuntimeException("Empty database/table/column name for property '" + name + "' not allowed");
         }
         return escapedName;
     }

modules/openapi-generator/src/main/java/org/openapitools/codegen/languages/LuaClientCodegen.java

@@ -111,13 +111,13 @@ public class LuaClientCodegen extends DefaultCodegen implements CodegenConfig {
                 )
         );
 
-        defaultIncludes = new HashSet<String>(
+        defaultIncludes = new HashSet<>(
                 Arrays.asList(
                         "map",
                         "array")
         );
 
-        languageSpecificPrimitives = new HashSet<String>(
+        languageSpecificPrimitives = new HashSet<>(
                 Arrays.asList(
                         "nil",
                         "string",
@@ -150,7 +150,7 @@ public class LuaClientCodegen extends DefaultCodegen implements CodegenConfig {
         typeMapping.put("ByteArray", "string");
         typeMapping.put("object", "TODO_OBJECT_MAPPING");
 
-        importMapping = new HashMap<String, String>();
+        importMapping = new HashMap<>();
         importMapping.put("time.Time", "time");
         importMapping.put("*os.File", "os");
         importMapping.put("os", "io/ioutil");
@@ -508,7 +508,7 @@ public class LuaClientCodegen extends DefaultCodegen implements CodegenConfig {
     }
 
     public Map<String, String> createMapping(String key, String value) {
-        Map<String, String> customImport = new HashMap<String, String>();
+        Map<String, String> customImport = new HashMap<>();
         customImport.put(key, value);
 
         return customImport;

modules/openapi-generator/src/main/java/org/openapitools/codegen/languages/MarkdownDocumentationCodegen.java

@@ -97,7 +97,7 @@ public class MarkdownDocumentationCodegen extends DefaultCodegen implements Code
     public String toParamName(String name) {
         if (reservedWords.contains(name)) {
             return escapeReservedWord(name);
-        } else if (((CharSequence) name).chars().anyMatch(character -> specialCharReplacements.keySet().contains("" + ((char) character)))) {
+        } else if (((CharSequence) name).chars().anyMatch(character -> specialCharReplacements.keySet().contains(String.valueOf((char) character)))) {
             return escape(name, specialCharReplacements, null, null);
         }
         return name;

modules/openapi-generator/src/main/java/org/openapitools/codegen/languages/MysqlSchemaCodegen.java

@@ -41,19 +41,19 @@ public class MysqlSchemaCodegen extends DefaultCodegen implements CodegenConfig
     public static final Integer ENUM_MAX_ELEMENTS = 65535;
     public static final Integer IDENTIFIER_MAX_LENGTH = 64;
 
-    protected Vector<String> mysqlNumericTypes = new Vector<String>(Arrays.asList(
+    protected Vector<String> mysqlNumericTypes = new Vector<>(Arrays.asList(
             "BIGINT", "BIT", "BOOL", "BOOLEAN", "DEC", "DECIMAL", "DOUBLE", "DOUBLE PRECISION", "FIXED", "FLOAT", "INT", "INTEGER", "MEDIUMINT", "NUMERIC", "REAL", "SMALLINT", "TINYINT"
     ));
 
-    protected Vector<String> mysqlDateAndTimeTypes = new Vector<String>(Arrays.asList(
+    protected Vector<String> mysqlDateAndTimeTypes = new Vector<>(Arrays.asList(
             "DATE", "DATETIME", "TIME", "TIMESTAMP", "YEAR"
     ));
 
-    protected Vector<String> mysqlStringTypes = new Vector<String>(Arrays.asList(
+    protected Vector<String> mysqlStringTypes = new Vector<>(Arrays.asList(
             "BINARY", "BLOB", "CHAR", "CHAR BYTE", "CHARACTER", "ENUM", "LONGBLOB", "LONGTEXT", "MEDIUMBLOB", "MEDIUMTEXT", "SET", "TEXT", "TINYBLOB", "TINYTEXT", "VARBINARY", "VARCHAR"
     ));
 
-    protected Vector<String> mysqlSpatialTypes = new Vector<String>(Arrays.asList(
+    protected Vector<String> mysqlSpatialTypes = new Vector<>(Arrays.asList(
             "GEOMETRY", "GEOMETRYCOLLECTION", "LINESTRING", "MULTILINESTRING", "MULTIPOINT", "MULTIPOLYGON", "POINT", "POLYGON"
     ));
 
@@ -125,7 +125,7 @@ public class MysqlSchemaCodegen extends DefaultCodegen implements CodegenConfig
         );
 
         // all types can be threaded as primitives except array, object and refs
-        languageSpecificPrimitives = new HashSet<String>(
+        languageSpecificPrimitives = new HashSet<>(
                 Arrays.asList(
                         "bool",
                         "boolean",
@@ -263,8 +263,8 @@ public class MysqlSchemaCodegen extends DefaultCodegen implements CodegenConfig
             String tableName = this.toTableName(modelName);
             String modelDescription = model.getDescription();
             Map<String, Object> modelVendorExtensions = model.getVendorExtensions();
-            Map<String, Object> mysqlSchema = new HashMap<String, Object>();
+            Map<String, Object> mysqlSchema = new HashMap<>();
-            Map<String, Object> tableDefinition = new HashMap<String, Object>();
+            Map<String, Object> tableDefinition = new HashMap<>();
 
             if (this.getIdentifierNamingConvention().equals("snake_case") && !modelName.equals(tableName)) {
                 // add original name in table comment
@@ -325,8 +325,8 @@ public class MysqlSchemaCodegen extends DefaultCodegen implements CodegenConfig
      */
     public void processIntegerTypeProperty(CodegenModel model, CodegenProperty property) {
         Map<String, Object> vendorExtensions = property.getVendorExtensions();
-        Map<String, Object> mysqlSchema = new HashMap<String, Object>();
+        Map<String, Object> mysqlSchema = new HashMap<>();
-        Map<String, Object> columnDefinition = new HashMap<String, Object>();
+        Map<String, Object> columnDefinition = new HashMap<>();
         ArrayList columnDataTypeArguments = new ArrayList();
         String baseName = property.getBaseName();
         String colName = this.toColumnName(baseName);
@@ -366,7 +366,7 @@ public class MysqlSchemaCodegen extends DefaultCodegen implements CodegenConfig
                 if (i > ENUM_MAX_ELEMENTS - 1) {
                     LOGGER.warn(
                             "ENUM column can have maximum of {} distinct elements, following value will be skipped: {}",
-                            ENUM_MAX_ELEMENTS.toString(), (String) enumValues.get(i));
+                            ENUM_MAX_ELEMENTS, (String) enumValues.get(i));
                     break;
                 }
                 String value = String.valueOf(enumValues.get(i));
@@ -417,8 +417,8 @@ public class MysqlSchemaCodegen extends DefaultCodegen implements CodegenConfig
      */
     public void processDecimalTypeProperty(CodegenModel model, CodegenProperty property) {
         Map<String, Object> vendorExtensions = property.getVendorExtensions();
-        Map<String, Object> mysqlSchema = new HashMap<String, Object>();
+        Map<String, Object> mysqlSchema = new HashMap<>();
-        Map<String, Object> columnDefinition = new HashMap<String, Object>();
+        Map<String, Object> columnDefinition = new HashMap<>();
         ArrayList columnDataTypeArguments = new ArrayList();
         String baseName = property.getBaseName();
         String colName = this.toColumnName(baseName);
@@ -457,7 +457,7 @@ public class MysqlSchemaCodegen extends DefaultCodegen implements CodegenConfig
                 if (i > ENUM_MAX_ELEMENTS - 1) {
                     LOGGER.warn(
                             "ENUM column can have maximum of {} distinct elements, following value will be skipped: {}",
-                            ENUM_MAX_ELEMENTS.toString(), (String) enumValues.get(i));
+                            ENUM_MAX_ELEMENTS, (String) enumValues.get(i));
                     break;
                 }
                 String value = String.valueOf(enumValues.get(i));
@@ -507,8 +507,8 @@ public class MysqlSchemaCodegen extends DefaultCodegen implements CodegenConfig
      */
     public void processBooleanTypeProperty(CodegenModel model, CodegenProperty property) {
         Map<String, Object> vendorExtensions = property.getVendorExtensions();
-        Map<String, Object> mysqlSchema = new HashMap<String, Object>();
+        Map<String, Object> mysqlSchema = new HashMap<>();
-        Map<String, Object> columnDefinition = new HashMap<String, Object>();
+        Map<String, Object> columnDefinition = new HashMap<>();
         ArrayList columnDataTypeArguments = new ArrayList();
         String baseName = property.getBaseName();
         String colName = this.toColumnName(baseName);
@@ -562,8 +562,8 @@ public class MysqlSchemaCodegen extends DefaultCodegen implements CodegenConfig
      */
     public void processStringTypeProperty(CodegenModel model, CodegenProperty property) {
         Map<String, Object> vendorExtensions = property.getVendorExtensions();
-        Map<String, Object> mysqlSchema = new HashMap<String, Object>();
+        Map<String, Object> mysqlSchema = new HashMap<>();
-        Map<String, Object> columnDefinition = new HashMap<String, Object>();
+        Map<String, Object> columnDefinition = new HashMap<>();
         ArrayList columnDataTypeArguments = new ArrayList();
         String baseName = property.getBaseName();
         String colName = this.toColumnName(baseName);
@@ -601,7 +601,7 @@ public class MysqlSchemaCodegen extends DefaultCodegen implements CodegenConfig
                 if (i > ENUM_MAX_ELEMENTS - 1) {
                     LOGGER.warn(
                             "ENUM column can have maximum of {} distinct elements, following value will be skipped: {}",
-                            ENUM_MAX_ELEMENTS.toString(), (String) enumValues.get(i));
+                            ENUM_MAX_ELEMENTS, (String) enumValues.get(i));
                     break;
                 }
                 String value = String.valueOf(enumValues.get(i));
@@ -645,8 +645,8 @@ public class MysqlSchemaCodegen extends DefaultCodegen implements CodegenConfig
      */
     public void processDateTypeProperty(CodegenModel model, CodegenProperty property) {
         Map<String, Object> vendorExtensions = property.getVendorExtensions();
-        Map<String, Object> mysqlSchema = new HashMap<String, Object>();
+        Map<String, Object> mysqlSchema = new HashMap<>();
-        Map<String, Object> columnDefinition = new HashMap<String, Object>();
+        Map<String, Object> columnDefinition = new HashMap<>();
         String baseName = property.getBaseName();
         String colName = this.toColumnName(baseName);
         String dataType = property.getDataType();
@@ -698,8 +698,8 @@ public class MysqlSchemaCodegen extends DefaultCodegen implements CodegenConfig
      */
     public void processJsonTypeProperty(CodegenModel model, CodegenProperty property) {
         Map<String, Object> vendorExtensions = property.getVendorExtensions();
-        Map<String, Object> mysqlSchema = new HashMap<String, Object>();
+        Map<String, Object> mysqlSchema = new HashMap<>();
-        Map<String, Object> columnDefinition = new HashMap<String, Object>();
+        Map<String, Object> columnDefinition = new HashMap<>();
         String baseName = property.getBaseName();
         String colName = this.toColumnName(baseName);
         String dataType = property.getDataType();
@@ -755,8 +755,8 @@ public class MysqlSchemaCodegen extends DefaultCodegen implements CodegenConfig
      */
     public void processUnknownTypeProperty(CodegenModel model, CodegenProperty property) {
         Map<String, Object> vendorExtensions = property.getVendorExtensions();
-        Map<String, Object> mysqlSchema = new HashMap<String, Object>();
+        Map<String, Object> mysqlSchema = new HashMap<>();
-        Map<String, Object> columnDefinition = new HashMap<String, Object>();
+        Map<String, Object> columnDefinition = new HashMap<>();
         String baseName = property.getBaseName();
         String colName = this.toColumnName(baseName);
         Boolean required = property.getRequired();
@@ -806,7 +806,7 @@ public class MysqlSchemaCodegen extends DefaultCodegen implements CodegenConfig
      * @return generated codegen property
      */
     public HashMap<String, Object> toCodegenMysqlDataTypeArgument(Object value) {
-        HashMap<String, Object> arg = new HashMap<String, Object>();
+        HashMap<String, Object> arg = new HashMap<>();
         if (value instanceof String) {
             arg.put("isString", true);
             arg.put("isFloat", false);
@@ -838,7 +838,7 @@ public class MysqlSchemaCodegen extends DefaultCodegen implements CodegenConfig
      * @return generated codegen property
      */
     public HashMap<String, Object> toCodegenMysqlDataTypeDefault(String defaultValue, String mysqlDataType) {
-        HashMap<String, Object> defaultMap = new HashMap<String, Object>();
+        HashMap<String, Object> defaultMap = new HashMap<>();
         if (defaultValue == null || defaultValue.toUpperCase(Locale.ROOT).equals("NULL")) {
             defaultMap.put("defaultValue", "NULL");
             defaultMap.put("isString", false);
@@ -1076,7 +1076,7 @@ public class MysqlSchemaCodegen extends DefaultCodegen implements CodegenConfig
 
         // identifier name cannot be empty
         if (escapedName.isEmpty()) {
-            throw new RuntimeException("Empty database/table/column name for property '" + name.toString() + "' not allowed");
+            throw new RuntimeException("Empty database/table/column name for property '" + name + "' not allowed");
         }
         return escapedName;
     }

modules/openapi-generator/src/main/java/org/openapitools/codegen/languages/NimClientCodegen.java

@@ -117,13 +117,13 @@ public class NimClientCodegen extends DefaultCodegen implements CodegenConfig {
                 )
         );
 
-        defaultIncludes = new HashSet<String>(
+        defaultIncludes = new HashSet<>(
                 Arrays.asList(
                         "array"
                 )
         );
 
-        languageSpecificPrimitives = new HashSet<String>(
+        languageSpecificPrimitives = new HashSet<>(
                 Arrays.asList(
                         "int",
                         "int8",

modules/openapi-generator/src/main/java/org/openapitools/codegen/languages/NodeJSExpressServerCodegen.java

@@ -439,7 +439,7 @@ public class NodeJSExpressServerCodegen extends DefaultCodegen implements Codege
 
         // only process files with js extension
         if ("js".equals(FilenameUtils.getExtension(file.toString()))) {
-            String command = jsPostProcessFile + " " + file.toString();
+            String command = jsPostProcessFile + " " + file;
             try {
                 Process p = Runtime.getRuntime().exec(command);
                 p.waitFor();

modules/openapi-generator/src/main/java/org/openapitools/codegen/languages/OCamlClientCodegen.java

@@ -672,7 +672,7 @@ public class OCamlClientCodegen extends DefaultCodegen implements CodegenConfig
     public String toEnumValueName(String name) {
         if (reservedWords.contains(name)) {
             return escapeReservedWord(name);
-        } else if (((CharSequence) name).chars().anyMatch(character -> specialCharReplacements.keySet().contains("" + ((char) character)))) {
+        } else if (((CharSequence) name).chars().anyMatch(character -> specialCharReplacements.keySet().contains(String.valueOf((char) character)))) {
             return escape(name, specialCharReplacements, Collections.singletonList("_"), null);
         } else {
             return name;
@@ -812,7 +812,7 @@ public class OCamlClientCodegen extends DefaultCodegen implements CodegenConfig
         }
         // only process files with ml or mli extension
         if ("ml".equals(FilenameUtils.getExtension(file.toString())) || "mli".equals(FilenameUtils.getExtension(file.toString()))) {
-            String command = ocamlPostProcessFile + " " + file.toString();
+            String command = ocamlPostProcessFile + " " + file;
             try {
                 Process p = Runtime.getRuntime().exec(command);
                 int exitValue = p.waitFor();

modules/openapi-generator/src/main/java/org/openapitools/codegen/languages/ObjcClientCodegen.java

@@ -43,7 +43,7 @@ public class ObjcClientCodegen extends DefaultCodegen implements CodegenConfig {
     public static final String DEFAULT_LICENSE = "Proprietary";
     public static final String CORE_DATA = "coreData";
 
-    protected Set<String> foundationClasses = new HashSet<String>();
+    protected Set<String> foundationClasses = new HashSet<>();
     protected String podName = "OpenAPIClient";
     protected String podVersion = "1.0.0";
     protected String classPrefix = "OAI";
@@ -60,7 +60,7 @@ public class ObjcClientCodegen extends DefaultCodegen implements CodegenConfig {
 
     protected boolean generateCoreData = false;
 
-    protected Set<String> advancedMappingTypes = new HashSet<String>();
+    protected Set<String> advancedMappingTypes = new HashSet<>();
 
     public ObjcClientCodegen() {
         super();
@@ -185,9 +185,9 @@ public class ObjcClientCodegen extends DefaultCodegen implements CodegenConfig {
                         "description", "class"
                 ));
 
-        importMapping = new HashMap<String, String>();
+        importMapping = new HashMap<>();
 
-        foundationClasses = new HashSet<String>(
+        foundationClasses = new HashSet<>(
                 Arrays.asList(
                         "NSNumber",
                         "NSObject",

modules/openapi-generator/src/main/java/org/openapitools/codegen/languages/PerlClientCodegen.java

@@ -614,7 +614,7 @@ public class PerlClientCodegen extends DefaultCodegen implements CodegenConfig {
         if ("t".equals(FilenameUtils.getExtension(file.toString())) ||
                 "pm".equals(FilenameUtils.getExtension(file.toString())) ||
                 "pl".equals(FilenameUtils.getExtension(file.toString()))) {
-            String command = perlTidyPath + " -b -bext='/' " + file.toString();
+            String command = perlTidyPath + " -b -bext='/' " + file;
             try {
                 Process p = Runtime.getRuntime().exec(command);
                 int exitValue = p.waitFor();

modules/openapi-generator/src/main/java/org/openapitools/codegen/languages/PhpSilexServerCodegen.java

@@ -90,7 +90,7 @@ public class PhpSilexServerCodegen extends DefaultCodegen implements CodegenConf
         additionalProperties.put(CodegenConstants.ARTIFACT_VERSION, artifactVersion);
 
         // ref: http://php.net/manual/en/language.types.intro.php
-        languageSpecificPrimitives = new HashSet<String>(
+        languageSpecificPrimitives = new HashSet<>(
                 Arrays.asList(
                         "boolean",
                         "int",
@@ -108,7 +108,7 @@ public class PhpSilexServerCodegen extends DefaultCodegen implements CodegenConf
         instantiationTypes.put("map", "map");
 
         // ref: https://github.com/OAI/OpenAPI-Specification/blob/master/versions/2.0.md#data-types
-        typeMapping = new HashMap<String, String>();
+        typeMapping = new HashMap<>();
         typeMapping.put("integer", "int");
         typeMapping.put("long", "int");
         typeMapping.put("float", "float");

modules/openapi-generator/src/main/java/org/openapitools/codegen/languages/PhpSymfonyServerCodegen.java

@@ -113,7 +113,7 @@ public class PhpSymfonyServerCodegen extends AbstractPhpCodegen implements Codeg
         outputFolder = "generated-code" + File.separator + "php";
         apiTemplateFiles.put("api_controller.mustache", ".php");
         modelTestTemplateFiles.put("testing/model_test.mustache", ".php");
-        apiTestTemplateFiles = new HashMap<String, String>();
+        apiTestTemplateFiles = new HashMap<>();
         apiTestTemplateFiles.put("testing/api_test.mustache", ".php");
         embeddedTemplateDir = templateDir = "php-symfony";
 
@@ -139,7 +139,7 @@ public class PhpSymfonyServerCodegen extends AbstractPhpCodegen implements Codeg
         );
 
         // ref: http://php.net/manual/en/language.types.intro.php
-        languageSpecificPrimitives = new HashSet<String>(
+        languageSpecificPrimitives = new HashSet<>(
                 Arrays.asList(
                         "bool",
                         "int",
@@ -157,7 +157,7 @@ public class PhpSymfonyServerCodegen extends AbstractPhpCodegen implements Codeg
                 )
         );
 
-        defaultIncludes = new HashSet<String>(
+        defaultIncludes = new HashSet<>(
                 Arrays.asList(
                         "\\DateTime",
                         "UploadedFile"
@@ -167,13 +167,13 @@ public class PhpSymfonyServerCodegen extends AbstractPhpCodegen implements Codeg
         variableNamingConvention = "camelCase";
 
         // provide primitives to mustache template
-        List sortedLanguageSpecificPrimitives = new ArrayList(languageSpecificPrimitives);
+        List<String> sortedLanguageSpecificPrimitives = new ArrayList<>(languageSpecificPrimitives);
         Collections.sort(sortedLanguageSpecificPrimitives);
         String primitives = "'" + StringUtils.join(sortedLanguageSpecificPrimitives, "', '") + "'";
         additionalProperties.put("primitives", primitives);
 
         // ref: https://github.com/OAI/OpenAPI-Specification/blob/master/versions/2.0.md#data-types
-        typeMapping = new HashMap<String, String>();
+        typeMapping = new HashMap<>();
         typeMapping.put("integer", "int");
         typeMapping.put("long", "int");
         typeMapping.put("decimal", "float");
@@ -370,13 +370,13 @@ public class PhpSymfonyServerCodegen extends AbstractPhpCodegen implements Codeg
         // Type-hintable primitive types
         // ref: http://php.net/manual/en/functions.arguments.php#functions.arguments.type-declaration
         if (phpLegacySupport) {
-            typeHintable = new HashSet<String>(
+            typeHintable = new HashSet<>(
                     Arrays.asList(
                             "array"
                     )
             );
         } else {
-            typeHintable = new HashSet<String>(
+            typeHintable = new HashSet<>(
                     Arrays.asList(
                             "array",
                             "bool",
@@ -396,7 +396,7 @@ public class PhpSymfonyServerCodegen extends AbstractPhpCodegen implements Codeg
         operations.put("controllerName", toControllerName((String) operations.get("pathPrefix")));
         operations.put("symfonyService", toSymfonyService((String) operations.get("pathPrefix")));
 
-        List<CodegenSecurity> authMethods = new ArrayList<CodegenSecurity>();
+        List<CodegenSecurity> authMethods = new ArrayList<>();
         List<CodegenOperation> operationList = (List<CodegenOperation>) operations.get("operation");
 
         for (CodegenOperation op : operationList) {

modules/openapi-generator/src/main/java/org/openapitools/codegen/languages/PowerShellClientCodegen.java

@@ -109,7 +109,7 @@ public class PowerShellClientCodegen extends DefaultCodegen implements CodegenCo
         modelPackage = packageName + File.separator + "Model";
 
         // https://blogs.msdn.microsoft.com/powershell/2010/01/07/how-objects-are-sent-to-and-from-remote-sessions/
-        languageSpecificPrimitives = new HashSet<String>(Arrays.asList(
+        languageSpecificPrimitives = new HashSet<>(Arrays.asList(
                 "Byte",
                 "SByte",
                 "Byte[]",
@@ -136,9 +136,9 @@ public class PowerShellClientCodegen extends DefaultCodegen implements CodegenCo
                 "Version"
         ));
 
-        commonVerbs = new HashMap<String, String>();
+        commonVerbs = new HashMap<>();
 
-        Map<String, List<String>> verbMappings = new HashMap<String, List<String>>();
+        Map<String, List<String>> verbMappings = new HashMap<>();
 
         // common
         verbMappings.put("Add", Arrays.asList("Append", "Attach", "Concatenate", "Insert"));
@@ -266,7 +266,7 @@ public class PowerShellClientCodegen extends DefaultCodegen implements CodegenCo
             }
         }
 
-        powershellVerbs = new HashSet<String>(Arrays.asList(
+        powershellVerbs = new HashSet<>(Arrays.asList(
                 "Add",
                 "Clear",
                 "Close",
@@ -368,9 +368,9 @@ public class PowerShellClientCodegen extends DefaultCodegen implements CodegenCo
                 "Use"
         ));
 
-        methodNames = new HashSet<String>();
+        methodNames = new HashSet<>();
 
-        nullablePrimitives = new HashSet<String>(Arrays.asList(
+        nullablePrimitives = new HashSet<>(Arrays.asList(
                 "System.Nullable[Byte]",
                 "System.Nullable[SByte]",
                 "System.Nullable[Int16]",
@@ -386,7 +386,7 @@ public class PowerShellClientCodegen extends DefaultCodegen implements CodegenCo
         ));
 
         // list of reserved words - must be in lower case
-        reservedWords = new HashSet<String>(Arrays.asList(
+        reservedWords = new HashSet<>(Arrays.asList(
                 // https://richardspowershellblog.wordpress.com/2009/05/02/powershell-reserved-words/
                 "begin",
                 "break",
@@ -456,7 +456,7 @@ public class PowerShellClientCodegen extends DefaultCodegen implements CodegenCo
                 "true"
         ));
 
-        paramNameReservedWords = new HashSet<String>(Arrays.asList(
+        paramNameReservedWords = new HashSet<>(Arrays.asList(
                 "args",
                 "error",
                 "executioncontext",
@@ -480,7 +480,7 @@ public class PowerShellClientCodegen extends DefaultCodegen implements CodegenCo
                 "true"
         ));
 
-        defaultIncludes = new HashSet<String>(Arrays.asList(
+        defaultIncludes = new HashSet<>(Arrays.asList(
                 "Byte",
                 "SByte",
                 "Byte[]",
@@ -507,7 +507,7 @@ public class PowerShellClientCodegen extends DefaultCodegen implements CodegenCo
                 "Version"
         ));
 
-        typeMapping = new HashMap<String, String>();
+        typeMapping = new HashMap<>();
         typeMapping.put("string", "String");
         typeMapping.put("boolean", "Boolean");
         typeMapping.put("integer", "Int32");
@@ -1012,8 +1012,8 @@ public class PowerShellClientCodegen extends DefaultCodegen implements CodegenCo
     @Override
     public Map<String, Object> postProcessOperationsWithModels(Map<String, Object> objs, List<Object> allModels) {
         Map<String, Object> operations = (Map<String, Object>) objs.get("operations");
-        HashMap<String, CodegenModel> modelMaps = new HashMap<String, CodegenModel>();
+        HashMap<String, CodegenModel> modelMaps = new HashMap<>();
-        HashMap<String, Integer> processedModelMaps = new HashMap<String, Integer>();
+        HashMap<String, Integer> processedModelMaps = new HashMap<>();
 
         for (Object o : allModels) {
             HashMap<String, Object> h = (HashMap<String, Object>) o;
@@ -1185,10 +1185,10 @@ public class PowerShellClientCodegen extends DefaultCodegen implements CodegenCo
             if (codegenParameter.items.isModel) {
                 String modelExample = constructExampleCode(codegenParameter.items, modelMaps, processedModelMap, requiredOnly);
                 if (!StringUtils.isEmpty(modelExample)) {
-                    example.append(modelExample + "\n");
+                    example.append(modelExample).append("\n");
                 }
 
-                example.append("$" + codegenParameter.paramName + " = @{ key_example = $" + codegenParameter.items.dataType + " }");
+                example.append("$").append(codegenParameter.paramName).append(" = @{ key_example = $").append(codegenParameter.items.dataType).append(" }");
             } else {
                 example.append("@{ key_example = ");
                 example.append(constructExampleCode(codegenParameter.items, modelMaps, processedModelMap, requiredOnly));
@@ -1280,7 +1280,7 @@ public class PowerShellClientCodegen extends DefaultCodegen implements CodegenCo
             if (codegenProperty.isModel) {
                 String modelExample = constructExampleCode(codegenProperty, modelMaps, processedModelMap, requiredOnly);
                 if (!StringUtils.isEmpty(modelExample)) {
-                    example.append(modelExample + "\n");
+                    example.append(modelExample).append("\n");
                 }
 
                 propertyExamples.add("-" + codegenProperty.name + " " + "$" + codegenProperty.dataType);
@@ -1293,26 +1293,26 @@ public class PowerShellClientCodegen extends DefaultCodegen implements CodegenCo
                 }
 
                 if (!StringUtils.isEmpty(modelExample)) {
-                    example.append(modelExample + "\n");
+                    example.append(modelExample).append("\n");
                 }
 
                 propertyExamples.add("-" + codegenProperty.name + " " + "$" + codegenProperty.complexType);
             } else if (codegenProperty.isArray && codegenProperty.items.isString) {
                 if (codegenProperty.items.isEnum || (codegenProperty.items.allowableValues != null && !codegenProperty.items.allowableValues.isEmpty())) {
                     example.append(constructEnumExample(codegenProperty.items.allowableValues));
-                    propertyExamples.add("-" + codegenProperty.name + " " + example.toString());
+                    propertyExamples.add("-" + codegenProperty.name + " " + example);
                 } else {
                     StringBuilder stringArrayPropertyValue = new StringBuilder();
                     String genericStringExample = codegenProperty.items.name + "_example";
 
                     stringArrayPropertyValue.append(constructStringExample(codegenProperty.name, codegenProperty.items.example, genericStringExample));
 
-                    propertyExamples.add("-" + codegenProperty.name + " " + stringArrayPropertyValue.toString());
+                    propertyExamples.add("-" + codegenProperty.name + " " + stringArrayPropertyValue);
                 }
             } else if (codegenProperty.isMap && codegenProperty.items.isModel) {
                 String modelExample = constructExampleCode(codegenProperty.items, modelMaps, processedModelMap, requiredOnly);
                 if (!StringUtils.isEmpty(modelExample)) {
-                    example.append(modelExample + "\n");
+                    example.append(modelExample).append("\n");
                 }
 
                 propertyExamples.add("-" + codegenProperty.name + " " + "@{ key_example = " + "$" + codegenProperty.complexType + " }");
@@ -1327,7 +1327,7 @@ public class PowerShellClientCodegen extends DefaultCodegen implements CodegenCo
         } else {
             example.append(codegenModel.name);
         }
-        example.append(" = " + this.modelsCmdletVerb + "-");
+        example.append(" = ").append(this.modelsCmdletVerb).append("-");
         if (this.useClassNameInModelsExamples) {
             example.append(codegenModel.classname);
         } else {
@@ -1353,7 +1353,7 @@ public class PowerShellClientCodegen extends DefaultCodegen implements CodegenCo
             codegenExample.equals("null") ||
             codegenExample.equals(genericStringExample)
         ) {
-            example.append("My" + codegenName);
+            example.append("My").append(codegenName);
         } else {
             example.append(codegenExample);
         }
@@ -1369,7 +1369,7 @@ public class PowerShellClientCodegen extends DefaultCodegen implements CodegenCo
         example.append("\"");
 
         List<Object> enumValues = (List<Object>) allowableValues.get("values");
-        example.append(String.valueOf(enumValues.get(0)));
+        example.append(enumValues.get(0));
 
         example.append("\"");
 
@@ -1474,7 +1474,7 @@ public class PowerShellClientCodegen extends DefaultCodegen implements CodegenCo
 
         // only process files with ps extension
         if ("ps".equals(FilenameUtils.getExtension(file.toString()))) {
-            String command = powershellPostProcessFile + " " + file.toString();
+            String command = powershellPostProcessFile + " " + file;
             try {
                 Process p = Runtime.getRuntime().exec(command);
                 int exitValue = p.waitFor();

modules/openapi-generator/src/main/java/org/openapitools/codegen/languages/ProtobufSchemaCodegen.java

@@ -86,13 +86,13 @@ public class ProtobufSchemaCodegen extends DefaultCodegen implements CodegenConf
         modelPackage = "messages";
         apiPackage = "services";
 
-        defaultIncludes = new HashSet<String>(
+        defaultIncludes = new HashSet<>(
                 Arrays.asList(
                         "map",
                         "array")
         );
 
-        languageSpecificPrimitives = new HashSet<String>(
+        languageSpecificPrimitives = new HashSet<>(
                 Arrays.asList(
                         "map",
                         "array",

modules/openapi-generator/src/main/java/org/openapitools/codegen/languages/PythonClientCodegen.java

@@ -611,12 +611,12 @@ public class PythonClientCodegen extends PythonLegacyClientCodegen {
         ComposedSchema cs = (ComposedSchema) schema;
 
         // these are the properties that are from properties in self cs or cs allOf
-        Map<String, Schema> selfProperties = new LinkedHashMap<String, Schema>();
+        Map<String, Schema> selfProperties = new LinkedHashMap<>();
-        List<String> selfRequired = new ArrayList<String>();
+        List<String> selfRequired = new ArrayList<>();
 
         // these are the properties that are from properties in cs oneOf or cs anyOf
-        Map<String, Schema> otherProperties = new LinkedHashMap<String, Schema>();
+        Map<String, Schema> otherProperties = new LinkedHashMap<>();
-        List<String> otherRequired = new ArrayList<String>();
+        List<String> otherRequired = new ArrayList<>();
 
         List<Schema> oneOfanyOfSchemas = new ArrayList<>();
         List<Schema> oneOf = cs.getOneOf();
@@ -631,7 +631,7 @@ public class PythonClientCodegen extends PythonLegacyClientCodegen {
             Schema refSchema = ModelUtils.getReferencedSchema(this.openAPI, sc);
             addProperties(otherProperties, otherRequired, refSchema);
         }
-        Set<String> otherRequiredSet = new HashSet<String>(otherRequired);
+        Set<String> otherRequiredSet = new HashSet<>(otherRequired);
 
         List<Schema> allOf = cs.getAllOf();
         if ((schema.getProperties() != null && !schema.getProperties().isEmpty()) || allOf != null) {
@@ -641,7 +641,7 @@ public class PythonClientCodegen extends PythonLegacyClientCodegen {
         if (result.discriminator != null) {
             selfRequired.add(result.discriminator.getPropertyBaseName());
         }
-        Set<String> selfRequiredSet = new HashSet<String>(selfRequired);
+        Set<String> selfRequiredSet = new HashSet<>(selfRequired);
 
         List<CodegenProperty> reqVars = result.getRequiredVars();
         List<CodegenProperty> reqVarsThatMustBeOptional = new ArrayList<>();
@@ -668,7 +668,7 @@ public class PythonClientCodegen extends PythonLegacyClientCodegen {
     protected void addParentContainer(CodegenModel model, String name, Schema schema) {
         super.addParentContainer(model, name, schema);
 
-        List<String> referencedModelNames = new ArrayList<String>();
+        List<String> referencedModelNames = new ArrayList<>();
         model.dataType = getTypeString(schema, "", "", referencedModelNames);
     }
 
@@ -688,7 +688,7 @@ public class PythonClientCodegen extends PythonLegacyClientCodegen {
         if (cm.requiredVars.size() > 0 && (cm.oneOf.size() > 0 || cm.anyOf.size() > 0)) {
             fixComposedSchemaRequiredVars(sc, cm);
         }
-        ArrayList<List<CodegenProperty>> listOfLists = new ArrayList<List<CodegenProperty>>();
+        ArrayList<List<CodegenProperty>> listOfLists = new ArrayList<>();
         listOfLists.add(cm.requiredVars);
         listOfLists.add(cm.optionalVars);
         for (List<CodegenProperty> cpList : listOfLists) {
@@ -940,7 +940,7 @@ public class PythonClientCodegen extends PythonLegacyClientCodegen {
             // store it in codegenModel.additionalPropertiesType.
             // The 'addProps' may be a reference, getTypeDeclaration will resolve
             // the reference.
-            List<String> referencedModelNames = new ArrayList<String>();
+            List<String> referencedModelNames = new ArrayList<>();
             getTypeString(addProps, "", "", referencedModelNames);
             if (referencedModelNames.size() != 0) {
                 // Models that are referenced in the 'additionalPropertiesType' keyword
@@ -1235,7 +1235,7 @@ public class PythonClientCodegen extends PythonLegacyClientCodegen {
             String itemModelName = getModelName(itemSchema);
             if (objExample instanceof Iterable && itemModelName == null) {
                 // If the example is already a list, return it directly instead of wrongly wrap it in another list
-                return fullPrefix + objExample.toString() + closeChars;
+                return fullPrefix + objExample + closeChars;
             }
             Set<Schema> newSeenSchemas = new HashSet<>(seenSchemas);
             newSeenSchemas.add(schema);
@@ -1493,7 +1493,7 @@ public class PythonClientCodegen extends PythonLegacyClientCodegen {
     protected Map<String, Schema> getModelNameToSchemaCache() {
         if (modelNameToSchemaCache == null) {
             // Create a cache to efficiently lookup schema based on model name.
-            Map<String, Schema> m = new HashMap<String, Schema>();
+            Map<String, Schema> m = new HashMap<>();
             ModelUtils.getSchemas(openAPI).forEach((key, schema) -> {
                 m.put(toModelName(key), schema);
             });

modules/openapi-generator/src/main/java/org/openapitools/codegen/languages/RClientCodegen.java

@@ -738,7 +738,7 @@ public class RClientCodegen extends DefaultCodegen implements CodegenConfig {
                     return "\"" + codegenProperty.example + "\"";
                 } else {
                     if (Boolean.TRUE.equals(codegenProperty.isEnum)) { // enum
-                        return "\"" + String.valueOf(((List<Object>) codegenProperty.allowableValues.get("values")).get(0)) + "\"";
+                        return "\"" + ((List<Object>) codegenProperty.allowableValues.get("values")).get(0) + "\"";
                     } else {
                         return "\"" + codegenProperty.name + "_example\"";
                     }

modules/openapi-generator/src/main/java/org/openapitools/codegen/languages/RustClientCodegen.java

@@ -124,13 +124,13 @@ public class RustClientCodegen extends DefaultCodegen implements CodegenConfig {
                 )
         );
 
-        defaultIncludes = new HashSet<String>(
+        defaultIncludes = new HashSet<>(
                 Arrays.asList(
                         "map",
                         "array")
         );
 
-        languageSpecificPrimitives = new HashSet<String>(
+        languageSpecificPrimitives = new HashSet<>(
                 Arrays.asList(
                         "i8", "i16", "i32", "i64",
                         "u8", "u16", "u32", "u64",

modules/openapi-generator/src/main/java/org/openapitools/codegen/languages/RustServerCodegen.java

@@ -53,7 +53,7 @@ public class RustServerCodegen extends DefaultCodegen implements CodegenConfig {
 
     private final Logger LOGGER = LoggerFactory.getLogger(RustServerCodegen.class);
 
-    private HashMap<String, String> modelXmlNames = new HashMap<String, String>();
+    private Map<String, String> modelXmlNames = new HashMap<String, String>();
 
     private static final String NO_FORMAT = "%%NO_FORMAT";
 
@@ -160,13 +160,13 @@ public class RustServerCodegen extends DefaultCodegen implements CodegenConfig {
                 )
         );
 
-        defaultIncludes = new HashSet<String>(
+        defaultIncludes = new HashSet<>(
                 Arrays.asList(
                         "map",
                         "array")
         );
 
-        languageSpecificPrimitives = new HashSet<String>(
+        languageSpecificPrimitives = new HashSet<>(
                 Arrays.asList(
                         "bool",
                         "char",
@@ -341,7 +341,7 @@ public class RustServerCodegen extends DefaultCodegen implements CodegenConfig {
         additionalProperties.put("serverHost", url.getHost());
         additionalProperties.put("serverPort", URLPathUtils.getPort(url, serverPort));
 
-        if (packageVersion == null || "".equals(packageVersion)) {
+        if (packageVersion == null || packageVersion.isEmpty()) {
             List<String> versionComponents = new ArrayList<>(Arrays.asList(info.getVersion().split("[.]")));
             if (versionComponents.size() < 1) {
                 versionComponents.add("1");
@@ -1087,7 +1087,7 @@ public class RustServerCodegen extends DefaultCodegen implements CodegenConfig {
 
     @Override
     public boolean isDataTypeFile(final String dataType) {
-        return dataType != null && dataType.equals(typeMapping.get("File").toString());
+        return dataType != null && dataType.equals(typeMapping.get("File"));
     }
 
     /**
@@ -1176,7 +1176,7 @@ public class RustServerCodegen extends DefaultCodegen implements CodegenConfig {
             }
             return datatype;
         } else if (p instanceof FileSchema) {
-            return typeMapping.get("File").toString();
+            return typeMapping.get("File");
         }
 
         return super.getTypeDeclaration(p);
@@ -1314,7 +1314,7 @@ public class RustServerCodegen extends DefaultCodegen implements CodegenConfig {
         // If we have callbacks, add the callbacks module, otherwise remove it
         boolean hasCallbacks = haveCallbacks(bundle);
         bundle.put("hasCallbacks", hasCallbacks);
-        SupportingFile[] callbackFiles = new SupportingFile[]{
+        SupportingFile[] callbackFiles = {
                 new SupportingFile("client-callbacks.mustache", "src/client", "callbacks.rs"),
                 new SupportingFile("server-callbacks.mustache", "src/server", "callbacks.rs"),
                 new SupportingFile("example-client-server.mustache", "examples/client", "server.rs")
@@ -1674,12 +1674,12 @@ public class RustServerCodegen extends DefaultCodegen implements CodegenConfig {
                 Process p = Runtime.getRuntime().exec(new String[]{commandPrefix, file.toString()});
                 int exitValue = p.waitFor();
                 if (exitValue != 0) {
-                    LOGGER.error("Error running the command ({} {}). Exit code: {}", commandPrefix, file.toString(), exitValue);
+                    LOGGER.error("Error running the command ({} {}). Exit code: {}", commandPrefix, file, exitValue);
                 } else {
-                    LOGGER.info("Successfully executed: {} {}", commandPrefix, file.toString());
+                    LOGGER.info("Successfully executed: {} {}", commandPrefix, file);
                 }
             } catch (InterruptedException | IOException e) {
-                LOGGER.error("Error running the command ({} ()). Exception: {}", commandPrefix, file.toString(), e.getMessage());
+                LOGGER.error("Error running the command ({} ()). Exception: {}", commandPrefix, file, e.getMessage());
                 // Restore interrupted state
                 Thread.currentThread().interrupt();
             }

modules/openapi-generator/src/main/java/org/openapitools/codegen/languages/ScalaFinchServerCodegen.java

@@ -87,7 +87,7 @@ public class ScalaFinchServerCodegen extends DefaultCodegen implements CodegenCo
                         "native")
         );
 
-        defaultIncludes = new HashSet<String>(
+        defaultIncludes = new HashSet<>(
                 Arrays.asList("double",
                         "Int",
                         "Long",
@@ -107,7 +107,7 @@ public class ScalaFinchServerCodegen extends DefaultCodegen implements CodegenCo
                         "Map")
         );
 
-        typeMapping = new HashMap<String, String>();
+        typeMapping = new HashMap<>();
         typeMapping.put("string", "String");
         typeMapping.put("boolean", "Boolean");
         typeMapping.put("integer", "Int");
@@ -158,7 +158,7 @@ public class ScalaFinchServerCodegen extends DefaultCodegen implements CodegenCo
         supportingFiles.add(new SupportingFile("endpoint.mustache", sourceFolder, "endpoint.scala"));
         supportingFiles.add(new SupportingFile("errors.mustache", sourceFolder, "errors.scala"));
 
-        languageSpecificPrimitives = new HashSet<String>(
+        languageSpecificPrimitives = new HashSet<>(
                 Arrays.asList(
                         "String",
                         "Boolean",
@@ -175,7 +175,7 @@ public class ScalaFinchServerCodegen extends DefaultCodegen implements CodegenCo
         instantiationTypes.put("array", "ArrayList");
         instantiationTypes.put("map", "HashMap");
 
-        importMapping = new HashMap<String, String>();
+        importMapping = new HashMap<>();
         importMapping.put("UUID", "java.util.UUID");
         importMapping.put("URI", "java.net.URI");
         importMapping.put("File", "java.io.File");

modules/openapi-generator/src/main/java/org/openapitools/codegen/languages/ScalaSttpClientCodegen.java

@@ -246,7 +246,7 @@ public class ScalaSttpClientCodegen extends AbstractScalaCodegen implements Code
      *
      * @param models processed models to be further processed
      */
-    @SuppressWarnings({"unchecked"})
+    @SuppressWarnings("unchecked")
     private void postProcessUpdateImports(final Map<String, Object> models) {
         final String prefix = modelPackage() + ".";
         Map<String, Object> enumRefs = new HashMap<String, Object>();

modules/openapi-generator/src/main/java/org/openapitools/codegen/languages/ScalatraServerCodegen.java

@@ -57,7 +57,7 @@ public class ScalatraServerCodegen extends AbstractScalaCodegen implements Codeg
         apiPackage = "org.openapitools.server.api";
         modelPackage = "org.openapitools.server.model";
 
-        defaultIncludes = new HashSet<String>(
+        defaultIncludes = new HashSet<>(
                 Arrays.asList("double",
                         "Int",
                         "Long",
@@ -118,7 +118,7 @@ public class ScalatraServerCodegen extends AbstractScalaCodegen implements Codeg
         supportingFiles.add(new SupportingFile("project/plugins.sbt", "project", "plugins.sbt"));
         supportingFiles.add(new SupportingFile("sbt", "", "sbt"));
 
-        importMapping = new HashMap<String, String>();
+        importMapping = new HashMap<>();
         importMapping.put("UUID", "java.util.UUID");
         importMapping.put("URI", "java.net.URI");
         importMapping.put("File", "java.io.File");

modules/openapi-generator/src/main/java/org/openapitools/codegen/languages/SpringCodegen.java

@@ -575,7 +575,7 @@ public class SpringCodegen extends AbstractJavaCodegen
                 basePath = basePath.substring(0, pos);
             }
 
-            if ("".equals(basePath)) {
+            if (basePath.isEmpty()) {
                 basePath = "default";
             } else {
                 co.subresourceOperation = !co.path.isEmpty();

modules/openapi-generator/src/main/java/org/openapitools/codegen/languages/StaticHtml2Generator.java

@@ -67,7 +67,7 @@ public class StaticHtml2Generator extends DefaultCodegen implements CodegenConfi
         outputFolder = "docs";
         embeddedTemplateDir = templateDir = "htmlDocs2";
 
-        defaultIncludes = new HashSet<String>();
+        defaultIncludes = new HashSet<>();
 
         cliOptions.add(new CliOption("appName", "short name of the application"));
         cliOptions.add(new CliOption("appDescription", "description of the application"));
@@ -100,10 +100,10 @@ public class StaticHtml2Generator extends DefaultCodegen implements CodegenConfi
         additionalProperties.put(CodegenConstants.ARTIFACT_VERSION, artifactVersion);
 
         supportingFiles.add(new SupportingFile("index.mustache", "", "index.html"));
-        reservedWords = new HashSet<String>();
+        reservedWords = new HashSet<>();
 
-        languageSpecificPrimitives = new HashSet<String>();
+        languageSpecificPrimitives = new HashSet<>();
-        importMapping = new HashMap<String, String>();
+        importMapping = new HashMap<>();
     }
 
     @Override

modules/openapi-generator/src/main/java/org/openapitools/codegen/languages/StaticHtmlGenerator.java

@@ -54,7 +54,7 @@ public class StaticHtmlGenerator extends DefaultCodegen implements CodegenConfig
         outputFolder = "docs";
         embeddedTemplateDir = templateDir = "htmlDocs";
 
-        defaultIncludes = new HashSet<String>();
+        defaultIncludes = new HashSet<>();
 
         cliOptions.add(new CliOption("appName", "short name of the application"));
         cliOptions.add(new CliOption("appDescription", "description of the application"));
@@ -79,10 +79,10 @@ public class StaticHtmlGenerator extends DefaultCodegen implements CodegenConfig
         additionalProperties.put(CodegenConstants.ARTIFACT_VERSION, artifactVersion);
 
         supportingFiles.add(new SupportingFile("index.mustache", "", "index.html"));
-        reservedWords = new HashSet<String>();
+        reservedWords = new HashSet<>();
 
-        languageSpecificPrimitives = new HashSet<String>();
+        languageSpecificPrimitives = new HashSet<>();
-        importMapping = new HashMap<String, String>();
+        importMapping = new HashMap<>();
     }
 
     /**
@@ -196,7 +196,7 @@ public class StaticHtmlGenerator extends DefaultCodegen implements CodegenConfig
     public String toVarName(String name) {
         if (reservedWords.contains(name)) {
             return escapeReservedWord(name);
-        } else if (((CharSequence) name).chars().anyMatch(character -> specialCharReplacements.keySet().contains("" + ((char) character)))) {
+        } else if (((CharSequence) name).chars().anyMatch(character -> specialCharReplacements.keySet().contains(String.valueOf((char) character)))) {
             return escape(name, specialCharReplacements, Arrays.asList("_"), null);
         } else {
             return name;

modules/openapi-generator/src/main/java/org/openapitools/codegen/languages/Swift4Codegen.java

@@ -790,7 +790,7 @@ public class Swift4Codegen extends DefaultCodegen implements CodegenConfig {
     public String toEnumValue(String value, String datatype) {
         // for string, array of string
         if ("String".equals(datatype) || "[String]".equals(datatype) || "[String:String]".equals(datatype)) {
-            return "\"" + String.valueOf(value) + "\"";
+            return "\"" + value + "\"";
         } else {
             return String.valueOf(value);
         }
@@ -963,7 +963,7 @@ public class Swift4Codegen extends DefaultCodegen implements CodegenConfig {
         }
         // only process files with swift extension
         if ("swift".equals(FilenameUtils.getExtension(file.toString()))) {
-            String command = swiftPostProcessFile + " " + file.toString();
+            String command = swiftPostProcessFile + " " + file;
             try {
                 Process p = Runtime.getRuntime().exec(command);
                 int exitValue = p.waitFor();

modules/openapi-generator/src/main/java/org/openapitools/codegen/languages/Swift5ClientCodegen.java

@@ -735,7 +735,7 @@ public class Swift5ClientCodegen extends DefaultCodegen implements CodegenConfig
                 // In Java, we need to be creative to get the Timestamp in Microseconds as a long.
                 Instant instant = ((OffsetDateTime) p.getDefault()).toInstant();
                 long epochMicro = TimeUnit.SECONDS.toMicros(instant.getEpochSecond()) + (instant.get(ChronoField.MICRO_OF_SECOND));
-                return "Date(timeIntervalSince1970: " + String.valueOf(epochMicro) + ".0 / 1_000_000)";
+                return "Date(timeIntervalSince1970: " + epochMicro + ".0 / 1_000_000)";
             } else if (ModelUtils.isStringSchema(p)) {
                 return "\"" + escapeText((String) p.getDefault()) + "\"";
             }
@@ -955,7 +955,7 @@ public class Swift5ClientCodegen extends DefaultCodegen implements CodegenConfig
     public String toEnumValue(String value, String datatype) {
         // for string, array of string
         if ("String".equals(datatype) || "[String]".equals(datatype) || "[String: String]".equals(datatype)) {
-            return "\"" + String.valueOf(value) + "\"";
+            return "\"" + value + "\"";
         } else {
             return String.valueOf(value);
         }
@@ -1115,7 +1115,7 @@ public class Swift5ClientCodegen extends DefaultCodegen implements CodegenConfig
         }
         // only process files with swift extension
         if ("swift".equals(FilenameUtils.getExtension(file.toString()))) {
-            String command = swiftPostProcessFile + " " + file.toString();
+            String command = swiftPostProcessFile + " " + file;
             try {
                 Process p = Runtime.getRuntime().exec(command);
                 int exitValue = p.waitFor();
@@ -1146,7 +1146,7 @@ public class Swift5ClientCodegen extends DefaultCodegen implements CodegenConfig
         List<CodegenOperation> operations = (List<CodegenOperation>) objectMap.get("operation");
         for (CodegenOperation operation : operations) {
             for (CodegenParameter cp : operation.allParams) {
-                cp.vendorExtensions.put("x-swift-example", constructExampleCode(cp, modelMaps, new HashSet<String>()));
+                cp.vendorExtensions.put("x-swift-example", constructExampleCode(cp, modelMaps, new HashSet<>()));
             }
         }
         return objs;

modules/openapi-generator/src/main/java/org/openapitools/codegen/languages/TypeScriptAngularClientCodegen.java

@@ -577,7 +577,7 @@ public class TypeScriptAngularClientCodegen extends AbstractTypeScriptClientCode
      * Parse imports
      */
     private Set<String> parseImports(CodegenModel cm) {
-        Set<String> newImports = new HashSet<String>();
+        Set<String> newImports = new HashSet<>();
         if (cm.imports.size() > 0) {
             for (String name : cm.imports) {
                 if (name.indexOf(" | ") >= 0) {

modules/openapi-generator/src/main/java/org/openapitools/codegen/languages/TypeScriptClientCodegen.java

@@ -146,13 +146,13 @@ public class TypeScriptClientCodegen extends DefaultCodegen implements CodegenCo
                 "Map"
         ));
 
-        languageGenericTypes = new HashSet<String>(Arrays.asList(
+        languageGenericTypes = new HashSet<>(Arrays.asList(
                 "Array"
         ));
 
         instantiationTypes.put("array", "Array");
 
-        typeMapping = new HashMap<String, String>();
+        typeMapping = new HashMap<>();
         typeMapping.put("Array", "Array");
         typeMapping.put("array", "Array");
         typeMapping.put("List", "Array");
@@ -185,7 +185,7 @@ public class TypeScriptClientCodegen extends DefaultCodegen implements CodegenCo
         cliOptions.add(new CliOption(NPM_VERSION, "The version of your npm package. If not provided, using the version from the OpenAPI specification file.").defaultValue(this.getNpmVersion()));
         cliOptions.add(new CliOption(NPM_REPOSITORY, "Use this property to set an url your private npmRepo in the package.json"));
         cliOptions.add(CliOption.newBoolean(SNAPSHOT,
-                "When setting this property to true, the version will be suffixed with -SNAPSHOT." + this.SNAPSHOT_SUFFIX_FORMAT.get().toPattern(),
+                "When setting this property to true, the version will be suffixed with -SNAPSHOT." + SNAPSHOT_SUFFIX_FORMAT.get().toPattern(),
                 false));
 
         cliOptions.add(new CliOption(CodegenConstants.MODEL_PROPERTY_NAMING, CodegenConstants.MODEL_PROPERTY_NAMING_DESC).defaultValue("camelCase"));
@@ -339,7 +339,7 @@ public class TypeScriptClientCodegen extends DefaultCodegen implements CodegenCo
      * @return TypeScript return type
      */
     private String getReturnType(List<CodegenResponse> responses) {
-        Set<String> returnTypes = new HashSet<String>();
+        Set<String> returnTypes = new HashSet<>();
         for (CodegenResponse response: responses) {
             if (response.is2xx) {
                 if (response.dataType != null) {
@@ -424,7 +424,7 @@ public class TypeScriptClientCodegen extends DefaultCodegen implements CodegenCo
     }
 
     protected String toTypescriptTypeName(final String name, String safePrefix) {
-        ArrayList<String> exceptions = new ArrayList<String>(Arrays.asList("\\|", " "));
+        ArrayList<String> exceptions = new ArrayList<>(Arrays.asList("\\|", " "));
         String sanName = sanitizeName(name, "(?![| ])\\W", exceptions);
 
         sanName = camelize(sanName);
@@ -507,7 +507,7 @@ public class TypeScriptClientCodegen extends DefaultCodegen implements CodegenCo
             if (!isFirst) {
                 b.append(" | ");
             }
-            b.append(toEnumValue(value.toString(), dataType));
+            b.append(toEnumValue(value, dataType));
             isFirst = false;
         }
         return b.toString();
@@ -1220,7 +1220,7 @@ public class TypeScriptClientCodegen extends DefaultCodegen implements CodegenCo
             String itemModelName = getModelName(itemSchema);
             if (objExample instanceof Iterable && itemModelName == null) {
                 // If the example is already a list, return it directly instead of wrongly wrap it in another list
-                return fullPrefix + objExample.toString() + closeChars;
+                return fullPrefix + objExample + closeChars;
             }
             Set<Schema> newSeenSchemas = new HashSet<>(seenSchemas);
             newSeenSchemas.add(schema);

modules/openapi-generator/src/main/java/org/openapitools/codegen/languages/TypeScriptFetchClientCodegen.java

@@ -186,8 +186,8 @@ public class TypeScriptFetchClientCodegen extends AbstractTypeScriptClientCodege
         }
         return "id".equals(name) ||
                 "ids".equals(name) ||
-                (name.length() >= 3 && name.substring(name.length() - 2).equals("Id")) ||
+                (name.length() >= 3 && name.endsWith("Id")) ||
-                (name.length() >= 4 && name.substring(name.length() - 3).equals("Ids"));
+                (name.length() >= 4 && name.endsWith("Ids"));
     }
 
     @Override
@@ -488,7 +488,7 @@ public class TypeScriptFetchClientCodegen extends AbstractTypeScriptClientCodege
                                 op.returnPassthrough = null;
                             }
                         }
-                    } else if (this.getDetectPassthroughModelsWithSuffixAndField() != null && op.returnBaseType.length() > this.getPassthroughSuffix().length() && op.returnBaseType.substring(op.returnBaseType.length() - this.getPassthroughSuffix().length()).equals(this.getPassthroughSuffix())) {
+                    } else if (this.getDetectPassthroughModelsWithSuffixAndField() != null && op.returnBaseType.length() > this.getPassthroughSuffix().length() && op.returnBaseType.endsWith(this.getPassthroughSuffix())) {
                         boolean foundMatch = false;
                         for (CodegenProperty var : cm.vars) {
                             if (var.name.equals(this.getPassthroughField())) {
@@ -635,7 +635,7 @@ public class TypeScriptFetchClientCodegen extends AbstractTypeScriptClientCodege
                         cm.returnPassthrough = null;
                     }
                 }
-            } else if (this.getDetectPassthroughModelsWithSuffixAndField() != null && cm.name.length() > this.getPassthroughSuffix().length() && cm.name.substring(cm.name.length() - this.getPassthroughSuffix().length()).equals(this.getPassthroughSuffix())) {
+            } else if (this.getDetectPassthroughModelsWithSuffixAndField() != null && cm.name.length() > this.getPassthroughSuffix().length() && cm.name.endsWith(this.getPassthroughSuffix())) {
                 boolean foundMatch = false;
                 for (CodegenProperty var : cm.vars) {
                     if (var.name.equals(this.getPassthroughField())) {

modules/openapi-generator/src/main/java/org/openapitools/codegen/languages/TypeScriptNestjsClientCodegen.java

@@ -387,14 +387,12 @@ public class TypeScriptNestjsClientCodegen extends AbstractTypeScriptClientCodeg
      * Parse imports
      */
     private Set<String> parseImports(CodegenModel cm) {
-        Set<String> newImports = new HashSet<String>();
+        Set<String> newImports = new HashSet<>();
         if (cm.imports.size() > 0) {
             for (String name : cm.imports) {
                 if (name.indexOf(" | ") >= 0) {
                     String[] parts = name.split(" \\| ");
-                    for (String s : parts) {
+                    newImports.addAll(Arrays.asList(parts));
-                        newImports.add(s);
-                    }
                 } else {
                     newImports.add(name);
                 }

modules/openapi-generator/src/main/java/org/openapitools/codegen/languages/TypeScriptNodeClientCodegen.java

@@ -103,7 +103,7 @@ public class TypeScriptNodeClientCodegen extends AbstractTypeScriptClientCodegen
     @Override
     protected void handleMethodResponse(Operation operation, Map<String, Schema> schemas, CodegenOperation op,
                                         ApiResponse methodResponse) {
-        handleMethodResponse(operation, schemas, op, methodResponse, Collections.<String, String>emptyMap());
+        handleMethodResponse(operation, schemas, op, methodResponse, Collections.emptyMap());
     }
 
     @Override

modules/openapi-generator/src/main/java/org/openapitools/codegen/templating/HandlebarsEngineAdapter.java

@@ -42,10 +42,10 @@ import java.util.Map;
 
 public class HandlebarsEngineAdapter extends AbstractTemplatingEngineAdapter {
      final Logger LOGGER = LoggerFactory.getLogger(HandlebarsEngineAdapter.class);
-    private final String[] extensions = new String[]{"handlebars", "hbs"};
+    private final String[] extensions = {"handlebars", "hbs"};
 
     // We use this as a simple lookup for valid file name extensions. This adapter will inspect .mustache (built-in) and infer the relevant handlebars filename
-    private final String[] canCompileFromExtensions = new String[]{".handlebars",".hbs",".mustache"};
+    private final String[] canCompileFromExtensions = {".handlebars",".hbs",".mustache"};
     private boolean infiniteLoops = false;
     private boolean prettyPrint = false;
 
@@ -92,7 +92,7 @@ public class HandlebarsEngineAdapter extends AbstractTemplatingEngineAdapter {
         return tmpl.apply(context);
     }
 
-    @SuppressWarnings({"java:S108"})
+    @SuppressWarnings("java:S108")
     public TemplateSource findTemplate(TemplatingExecutor generator, String templateFile) {
         String[] possibilities = getModifiedFileLocation(templateFile);
         for (String file : possibilities) {

modules/openapi-generator/src/main/java/org/openapitools/codegen/templating/MustacheEngineAdapter.java

@@ -43,7 +43,7 @@ public class MustacheEngineAdapter implements TemplatingEngineAdapter {
         return "mustache";
     }
 
-    private final String[] extensions = new String[]{"mustache"};
+    private final String[] extensions = {"mustache"};
     Mustache.Compiler compiler = Mustache.compiler();
 
     /**
@@ -65,7 +65,7 @@ public class MustacheEngineAdapter implements TemplatingEngineAdapter {
         return tmpl.execute(bundle);
     }
 
-    @SuppressWarnings({"java:S108"}) // catch-all is expected, and is later thrown
+    @SuppressWarnings("java:S108") // catch-all is expected, and is later thrown
     public Reader findTemplate(TemplatingExecutor generator, String name) {
         for (String extension : extensions) {
             final String templateName = name + "." + extension;

modules/openapi-generator/src/main/java/org/openapitools/codegen/utils/ModelUtils.java

@@ -1073,7 +1073,7 @@ public class ModelUtils {
      */
     public static Schema unaliasSchema(OpenAPI openAPI,
                                        Schema schema) {
-        return unaliasSchema(openAPI, schema, Collections.<String, String>emptyMap());
+        return unaliasSchema(openAPI, schema, Collections.emptyMap());
     }
 
     /**
@@ -1258,7 +1258,7 @@ public class ModelUtils {
         } else if (composed.getOneOf() != null && !composed.getOneOf().isEmpty()) {
             return composed.getOneOf();
         } else {
-            return Collections.<Schema>emptyList();
+            return Collections.emptyList();
         }
     }
 

modules/openapi-generator/src/main/java/org/openapitools/codegen/utils/OneOfImplementorAdditionalData.java

@@ -119,10 +119,7 @@ public class OneOfImplementorAdditionalData {
         }
 
         // Add oneOf-containing models properties - we need to properly set the hasMore values to make rendering correct
-        for (int i = 0; i < additionalProps.size(); i++) {
+        implcm.vars.addAll(additionalProps);
-            CodegenProperty var = additionalProps.get(i);
-            implcm.vars.add(var);
-        }
 
         // Add imports
         for (Map<String, String> oneImport : additionalImports) {

modules/openapi-generator/src/main/java/org/openapitools/codegen/utils/StringUtils.java

@@ -153,7 +153,7 @@ public class StringUtils {
 
             m = camelizeSlashPattern.matcher(word);
             while (m.find()) {
-                word = m.replaceFirst("" + Character.toUpperCase(m.group(1).charAt(0)) + m.group(1).substring(1)/*.toUpperCase()*/);
+                word = m.replaceFirst(Character.toUpperCase(m.group(1).charAt(0)) + m.group(1).substring(1)/*.toUpperCase()*/);
                 m = camelizeSlashPattern.matcher(word);
             }
 
@@ -256,7 +256,7 @@ public class StringUtils {
         EscapedNameOptions ns = new EscapedNameOptions(name, replacementMap.keySet(), charactersToAllow, appendToReplacement);
         return escapedWordsCache.get(ns, wordToEscape -> {
             String result = name.chars().mapToObj(c -> {
-                String character = "" + (char) c;
+                String character = String.valueOf((char) c);
                 if (charactersToAllow != null && charactersToAllow.contains(character)) {
                     return character;
                 } else if (replacementMap.containsKey(character)) {
@@ -264,7 +264,7 @@ public class StringUtils {
                 } else {
                     return character;
                 }
-            }).reduce( (c1, c2) -> "" + c1 + c2).orElse(null);
+            }).reduce( (c1, c2) -> c1 + c2).orElse(null);
 
             if (result != null) return result;
             throw new RuntimeException("Word '" + name + "' could not be escaped.");

modules/openapi-generator/src/test/java/org/openapitools/codegen/DefaultCodegenTest.java

@@ -2425,7 +2425,7 @@ public class DefaultCodegenTest {
         Schema sc = openAPI.getComponents().getSchemas().get(modelName);
         CodegenModel cm = codegen.fromModel(modelName, sc);
 
-        final Set<CodegenDiscriminator.MappedModel> expectedMappedModels = new HashSet<>(Arrays.asList(new CodegenDiscriminator.MappedModel("UserSleep", "UserSleep")));
+        final Set<CodegenDiscriminator.MappedModel> expectedMappedModels = Sets.newHashSet(new CodegenDiscriminator.MappedModel("UserSleep", "UserSleep"));
         final Set<CodegenDiscriminator.MappedModel> mappedModels = cm.getDiscriminator().getMappedModels();
         assertEquals(mappedModels, expectedMappedModels);
 

modules/openapi-generator/src/test/java/org/openapitools/codegen/TestUtils.java

@@ -116,12 +116,12 @@ public class TestUtils {
 
     public static void ensureContainsFile(List<File> generatedFiles, File root, String filename) {
         Path path = root.toPath().resolve(filename);
-        assertTrue(generatedFiles.contains(path.toFile()), "File '" + path.toAbsolutePath().toString() + "' was not found in the list of generated files");
+        assertTrue(generatedFiles.contains(path.toFile()), "File '" + path.toAbsolutePath() + "' was not found in the list of generated files");
     }
 
     public static void ensureDoesNotContainsFile(List<File> generatedFiles, File root, String filename) {
         Path path = root.toPath().resolve(filename);
-        assertFalse(generatedFiles.contains(path.toFile()), "File '" + path.toAbsolutePath().toString() + "' was found in the list of generated files");
+        assertFalse(generatedFiles.contains(path.toFile()), "File '" + path.toAbsolutePath() + "' was found in the list of generated files");
     }
 
     public static void validateJavaSourceFiles(Map<String, String> fileMap) {
@@ -167,7 +167,7 @@ public class TestUtils {
             for (String line : lines)
                 assertTrue(file.contains(linearize(line)), "File does not contain line [" + line + "]");
         } catch (IOException e) {
-            fail("Unable to evaluate file " + path.toString());
+            fail("Unable to evaluate file " + path);
         }
     }
 
@@ -180,7 +180,7 @@ public class TestUtils {
         try {
             generatedFile = new String(Files.readAllBytes(path), StandardCharsets.UTF_8);
         } catch (IOException e) {
-            fail("Unable to evaluate file " + path.toString());
+            fail("Unable to evaluate file " + path);
         }
         String file = linearize(generatedFile);
         assertNotNull(file);