Merge remote-tracking branch 'origin/3.4.x' into 4.0.x

2026-03-19 10:09:08 +00:00 · 2018-10-26 18:41:58 +08:00
parent 30062afc7c 9422dea149
commit 4a47acce19
755 changed files with 23905 additions and 2474 deletions
--- a/modules/openapi-generator/src/main/java/org/openapitools/codegen/CodegenConstants.java
+++ b/modules/openapi-generator/src/main/java/org/openapitools/codegen/CodegenConstants.java
@@ -278,4 +278,5 @@ public class CodegenConstants {
    public static final String ENABLE_POST_PROCESS_FILE = "enablePostProcessFile";
    public static final String ENABLE_POST_PROCESS_FILE_DESC = "Enable post-processing file using environment variables.";

+    public static final String OPEN_API_SPEC_NAME = "openAPISpecName";
 }
--- a/modules/openapi-generator/src/main/java/org/openapitools/codegen/CodegenParameter.java
+++ b/modules/openapi-generator/src/main/java/org/openapitools/codegen/CodegenParameter.java
@@ -25,13 +25,13 @@ import java.util.Map;
 public class CodegenParameter {
    public boolean isFormParam, isQueryParam, isPathParam, isHeaderParam,
            isCookieParam, isBodyParam, hasMore, isContainer,
-            secondaryParam, isCollectionFormatMulti, isPrimitiveType;
+            secondaryParam, isCollectionFormatMulti, isPrimitiveType, isModel;
    public String baseName, paramName, dataType, datatypeWithEnum, dataFormat,
          collectionFormat, description, unescapedDescription, baseType, defaultValue, enumName;

    public String example; // example value (x-example)
    public String jsonSchema;
-    public boolean isString, isNumeric, isInteger, isLong, isNumber, isFloat, isDouble, isByteArray, isBinary, isBoolean, isDate, isDateTime, isUuid;
+    public boolean isString, isNumeric, isInteger, isLong, isNumber, isFloat, isDouble, isByteArray, isBinary, isBoolean, isDate, isDateTime, isUuid, isEmail;
    public boolean isListContainer, isMapContainer;
    public boolean isFile;
    public boolean isEnum;
@@ -110,6 +110,7 @@ public class CodegenParameter {
        output.collectionFormat = this.collectionFormat;
        output.isCollectionFormatMulti = this.isCollectionFormatMulti;
        output.isPrimitiveType = this.isPrimitiveType;
+        output.isModel = this.isModel;
        output.description = this.description;
        output.unescapedDescription = this.unescapedDescription;
        output.baseType = this.baseType;
@@ -165,6 +166,7 @@ public class CodegenParameter {
        output.isDate = this.isDate;
        output.isDateTime = this.isDateTime;
        output.isUuid = this.isUuid;
+        output.isEmail = this.isEmail;
        output.isListContainer = this.isListContainer;
        output.isMapContainer = this.isMapContainer;

@@ -201,6 +203,8 @@ public class CodegenParameter {
            return false;
        if (isPrimitiveType != that.isPrimitiveType)
            return false;
+        if (isModel != that.isModel)
+            return false;
        if (baseName != null ? !baseName.equals(that.baseName) : that.baseName != null)
            return false;
        if (paramName != null ? !paramName.equals(that.paramName) : that.paramName != null)
@@ -253,6 +257,8 @@ public class CodegenParameter {
            return false;
        if (isUuid != that.isUuid)
            return false;
+        if (isEmail != that.isEmail)
+            return false;
        if (isListContainer != that.isListContainer)
            return false;
        if (isMapContainer != that.isMapContainer)
@@ -312,6 +318,7 @@ public class CodegenParameter {
        result = 31 * result + (secondaryParam ? 13:31);
        result = 31 * result + (isCollectionFormatMulti ? 13:31);
        result = 31 * result + (isPrimitiveType ? 13:31);
+        result = 31 * result + (isModel ? 13:31);
        result = 31 * result + (baseName != null ? baseName.hashCode() : 0);
        result = 31 * result + (paramName != null ? paramName.hashCode() : 0);
        result = 31 * result + (dataType != null ? dataType.hashCode() : 0);
@@ -338,6 +345,7 @@ public class CodegenParameter {
        result = 31 * result + (isDate ? 13:31);
        result = 31 * result + (isDateTime ? 13:31);
        result = 31 * result + (isUuid ? 13:31);
+        result = 31 * result + (isEmail ? 13:31);
        result = 31 * result + (isListContainer ? 13:31);
        result = 31 * result + (isMapContainer ? 13:31);
        result = 31 * result + (isFile ? 13:31);
@@ -378,6 +386,7 @@ public class CodegenParameter {
                ", secondaryParam=" + secondaryParam +
                ", isCollectionFormatMulti=" + isCollectionFormatMulti +
                ", isPrimitiveType=" + isPrimitiveType +
+                ", isModel=" + isModel +
                ", baseName='" + baseName + '\'' +
                ", paramName='" + paramName + '\'' +
                ", dataType='" + dataType + '\'' +
@@ -404,6 +413,7 @@ public class CodegenParameter {
                ", isDate=" + isDate +
                ", isDateTime=" + isDateTime +
                ", isUuid=" + isUuid +
+                ", isEmail=" + isEmail +
                ", isListContainer=" + isListContainer +
                ", isMapContainer=" + isMapContainer +
                ", isFile=" + isFile +
--- a/modules/openapi-generator/src/main/java/org/openapitools/codegen/CodegenProperty.java
+++ b/modules/openapi-generator/src/main/java/org/openapitools/codegen/CodegenProperty.java
@@ -55,8 +55,8 @@ public class CodegenProperty implements Cloneable {
    public boolean exclusiveMaximum;
    public boolean hasMore, required, secondaryParam;
    public boolean hasMoreNonReadOnly; // for model constructor, true if next property is not readonly
-    public boolean isPrimitiveType, isContainer, isNotContainer;
-    public boolean isString, isNumeric, isInteger, isLong, isNumber, isFloat, isDouble, isByteArray, isBinary, isFile, isBoolean, isDate, isDateTime, isUuid;
+    public boolean isPrimitiveType, isModel, isContainer, isNotContainer;
+    public boolean isString, isNumeric, isInteger, isLong, isNumber, isFloat, isDouble, isByteArray, isBinary, isFile, isBoolean, isDate, isDateTime, isUuid, isEmail;
    public boolean isListContainer, isMapContainer;
    public boolean isEnum;
    public boolean isReadOnly;
@@ -438,6 +438,7 @@ public class CodegenProperty implements Cloneable {
        result = prime * result + (isEnum ? 1231 : 1237);
        result = prime * result + ((isNotContainer ? 13:31));
        result = prime * result + ((isPrimitiveType  ? 13:31));
+        result = prime * result + ((isModel  ? 13:31));
        result = prime * result + ((isReadOnly  ? 13:31));
        result = prime * result + ((isWriteOnly  ? 13:31));
        result = prime * result + ((isNullable  ? 13:31));
@@ -472,6 +473,7 @@ public class CodegenProperty implements Cloneable {
        result = prime * result + ((isDate  ? 13:31));
        result = prime * result + ((isDateTime ? 13:31));
        result = prime * result + ((isUuid ? 13:31));
+        result = prime * result + ((isEmail ? 13:31));
        result = prime * result + ((isMapContainer ? 13:31));
        result = prime * result + ((isListContainer  ? 13:31));
        result = prime * result + Objects.hashCode(isInherited);
@@ -579,6 +581,9 @@ public class CodegenProperty implements Cloneable {
        if (this.isPrimitiveType != other.isPrimitiveType) {
            return false;
        }
+        if (this.isModel != other.isModel) {
+            return false;
+        }
        if (this.isContainer != other.isContainer) {
            return false;
        }
@@ -649,6 +654,9 @@ public class CodegenProperty implements Cloneable {
        if (this.isUuid != other.isUuid) {
            return false;
        }
+        if (this.isEmail != other.isEmail) {
+            return false;
+        }
        if (this.isBinary != other.isBinary) {
            return false;
        }
@@ -759,6 +767,7 @@ public class CodegenProperty implements Cloneable {
                ", secondaryParam=" + secondaryParam +
                ", hasMoreNonReadOnly=" + hasMoreNonReadOnly +
                ", isPrimitiveType=" + isPrimitiveType +
+                ", isModel=" + isModel +
                ", isContainer=" + isContainer +
                ", isNotContainer=" + isNotContainer +
                ", isString=" + isString +
@@ -775,6 +784,7 @@ public class CodegenProperty implements Cloneable {
                ", isDate=" + isDate +
                ", isDateTime=" + isDateTime +
                ", isUuid=" + isUuid +
+                ", isEmail=" + isEmail +
                ", isListContainer=" + isListContainer +
                ", isMapContainer=" + isMapContainer +
                ", isEnum=" + isEnum +
--- a/modules/openapi-generator/src/main/java/org/openapitools/codegen/CodegenResponse.java
+++ b/modules/openapi-generator/src/main/java/org/openapitools/codegen/CodegenResponse.java
@@ -30,7 +30,7 @@ public class CodegenResponse {
    public List<Map<String, Object>> examples;
    public String dataType, baseType, containerType;
    public boolean hasHeaders;
-    public boolean isString, isNumeric, isInteger, isLong, isNumber, isFloat, isDouble, isByteArray, isBoolean, isDate, isDateTime, isUuid;
+    public boolean isString, isNumeric, isInteger, isLong, isNumber, isFloat, isDouble, isByteArray, isBoolean, isDate, isDateTime, isUuid, isEmail;
    public boolean isDefault;
    public boolean simpleType;
    public boolean primitiveType;
--- a/modules/openapi-generator/src/main/java/org/openapitools/codegen/DefaultCodegen.java
+++ b/modules/openapi-generator/src/main/java/org/openapitools/codegen/DefaultCodegen.java
@@ -1895,6 +1895,9 @@ public class DefaultCodegen implements CodegenConfig {
                // keep isString to true to make it backward compatible
                property.isString = true;
                property.isUuid = true;
+            } else if (ModelUtils.isEmailSchema(p)) {
+                property.isString = true;
+                property.isEmail = true;
            } else {
                property.isString = true;
            }
@@ -2175,6 +2178,7 @@ public class DefaultCodegen implements CodegenConfig {
            property.isPrimitiveType = true;
        } else {
            property.complexType = property.baseType;
+            property.isModel = true;
        }
    }

@@ -2578,8 +2582,9 @@ public class DefaultCodegen implements CodegenConfig {
            }

            r.dataType = cp.dataType;
-
-            if (Boolean.TRUE.equals(cp.isString) && Boolean.TRUE.equals(cp.isUuid)) {
+            if (Boolean.TRUE.equals(cp.isString) && Boolean.TRUE.equals(cp.isEmail)) {
+                r.isEmail = true;
+            } else if (Boolean.TRUE.equals(cp.isString) && Boolean.TRUE.equals(cp.isUuid)) {
                r.isUuid = true;
            } else if (Boolean.TRUE.equals(cp.isByteArray)) {
                r.isByteArray = true;
@@ -3840,8 +3845,9 @@ public class DefaultCodegen implements CodegenConfig {
            LOGGER.error("Codegen Property cannot be null.");
            return;
        }
-
-        if (Boolean.TRUE.equals(property.isUuid) && Boolean.TRUE.equals(property.isString)) {
+        if (Boolean.TRUE.equals(property.isEmail) && Boolean.TRUE.equals(property.isString)) {
+            parameter.isEmail = true;
+        } else if (Boolean.TRUE.equals(property.isUuid) && Boolean.TRUE.equals(property.isString)) {
            parameter.isUuid = true;
        } else if (Boolean.TRUE.equals(property.isByteArray)) {
            parameter.isByteArray = true;
@@ -4515,6 +4521,9 @@ public class DefaultCodegen implements CodegenConfig {
                schema.setName(name);
                codegenModel = fromModel(name, schema, schemas);
            }
+            if (codegenModel != null) {
+                codegenParameter.isModel = true;
+            }

            if (codegenModel != null && !codegenModel.emptyVars) {
                if (StringUtils.isEmpty(bodyParameterName)) {
--- a/modules/openapi-generator/src/main/java/org/openapitools/codegen/InlineModelResolver.java
+++ b/modules/openapi-generator/src/main/java/org/openapitools/codegen/InlineModelResolver.java
@@ -500,6 +500,7 @@ public class InlineModelResolver {
        model.setExample(example);
        model.setName(object.getName());
        model.setXml(xml);
+        model.setRequired(object.getRequired());
        if (properties != null) {
            flattenProperties(properties, path);
            model.setProperties(properties);
@@ -545,6 +546,9 @@ public class InlineModelResolver {

    public void copyVendorExtensions(Schema source, Schema target) {
        Map<String, Object> vendorExtensions = source.getExtensions();
+        if (vendorExtensions == null) {
+             return;
+        }
        for (String extName : vendorExtensions.keySet()) {
            target.addExtension(extName, vendorExtensions.get(extName));
        }
--- a/modules/openapi-generator/src/main/java/org/openapitools/codegen/config/CodegenConfigurator.java
+++ b/modules/openapi-generator/src/main/java/org/openapitools/codegen/config/CodegenConfigurator.java
@@ -549,7 +549,6 @@ public class CodegenConfigurator implements Serializable {
        final List<AuthorizationValue> authorizationValues = AuthParser.parse(auth);
        ParseOptions options = new ParseOptions();
        options.setResolve(true);
-        options.setFlatten(true);
        SwaggerParseResult result = new OpenAPIParser().readLocation(inputSpec, authorizationValues, options);

        Set<String> validationMessages = new HashSet<>(result.getMessages());
--- a/modules/openapi-generator/src/main/java/org/openapitools/codegen/languages/AbstractJavaCodegen.java
+++ b/modules/openapi-generator/src/main/java/org/openapitools/codegen/languages/AbstractJavaCodegen.java
@@ -27,6 +27,7 @@ import io.swagger.v3.oas.models.media.Schema;
 import io.swagger.v3.oas.models.media.StringSchema;
 import io.swagger.v3.parser.util.SchemaTypeUtil;

+import org.apache.commons.io.FilenameUtils;
 import org.apache.commons.lang3.BooleanUtils;
 import org.apache.commons.lang3.StringUtils;
 import org.openapitools.codegen.CliOption;
@@ -212,6 +213,10 @@ public abstract class AbstractJavaCodegen extends DefaultCodegen implements Code
    public void processOpts() {
        super.processOpts();

+        if (StringUtils.isEmpty(System.getenv("JAVA_POST_PROCESS_FILE"))) {
+            LOGGER.info("Environment variable JAVA_POST_PROCESS_FILE not defined so the Java code may not be properly formatted. To define it, try 'export JAVA_POST_PROCESS_FILE=\"/usr/local/bin/clang-format -i\"' (Linux/Mac)");
+        }
+
        if (additionalProperties.containsKey(SUPPORT_JAVA6)) {
            this.setSupportJava6(Boolean.valueOf(additionalProperties.get(SUPPORT_JAVA6).toString()));
        }
@@ -226,7 +231,6 @@ public abstract class AbstractJavaCodegen extends DefaultCodegen implements Code
            this.setBooleanGetterPrefix(additionalProperties.get(BOOLEAN_GETTER_PREFIX).toString());
        }
        additionalProperties.put(BOOLEAN_GETTER_PREFIX, booleanGetterPrefix);
-
        if (additionalProperties.containsKey(USE_NULL_FOR_UNKNOWN_ENUM_VALUE)) {
            this.setUseNullForUnknownEnumValue(Boolean.valueOf(additionalProperties.get(USE_NULL_FOR_UNKNOWN_ENUM_VALUE).toString()));
        }
@@ -1382,6 +1386,35 @@ public abstract class AbstractJavaCodegen extends DefaultCodegen implements Code
        return tag;
    }

+    @Override
+    public void postProcessFile(File file, String fileType) {
+        if (file == null) {
+            return;
+        }
+
+        String javaPostProcessFile = System.getenv("JAVA_POST_PROCESS_FILE");
+        if (StringUtils.isEmpty(javaPostProcessFile)) {
+            return; // skip if JAVA_POST_PROCESS_FILE env variable is not defined
+        }
+
+        // only process files with hs extension
+        if ("java".equals(FilenameUtils.getExtension(file.toString()))) {
+            String command = javaPostProcessFile + " " + file.toString();
+            try {
+                Process p = Runtime.getRuntime().exec(command);
+                p.waitFor();
+                int exitValue = p.exitValue();
+                if (exitValue != 0) {
+                    LOGGER.error("Error running the command ({}). Exit value: {}", command, exitValue);
+                } else {
+                    LOGGER.info("Successfully executed: " + command);
+                }
+            } catch (Exception e) {
+                LOGGER.error("Error running the command ({}). Exception: {}", command, e.getMessage());
+            }
+        }
+    }
+
    public void setParentGroupId(final String parentGroupId) {
        this.parentGroupId = parentGroupId;
    }
--- a/modules/openapi-generator/src/main/java/org/openapitools/codegen/languages/CppPistacheServerCodegen.java
+++ b/modules/openapi-generator/src/main/java/org/openapitools/codegen/languages/CppPistacheServerCodegen.java
@@ -82,8 +82,7 @@ public class CppPistacheServerCodegen extends AbstractCppCodegen {
        apiTemplateFiles.put("api-header.mustache", ".h");
        apiTemplateFiles.put("api-source.mustache", ".cpp");
        apiTemplateFiles.put("api-impl-header.mustache", ".h");
-        apiTemplateFiles.put("api-impl-source.mustache", ".cpp");
-        apiTemplateFiles.put("main-api-server.mustache", ".cpp");
+        apiTemplateFiles.put("api-impl-source.mustache", ".cpp");        

        embeddedTemplateDir = templateDir = "cpp-pistache-server";

@@ -97,6 +96,7 @@ public class CppPistacheServerCodegen extends AbstractCppCodegen {
        supportingFiles.add(new SupportingFile("modelbase-source.mustache", "model", modelNamePrefix + "ModelBase.cpp"));
        supportingFiles.add(new SupportingFile("helpers-header.mustache", "model", modelNamePrefix + "Helpers.h"));
        supportingFiles.add(new SupportingFile("helpers-source.mustache", "model", modelNamePrefix + "Helpers.cpp"));
+        supportingFiles.add(new SupportingFile("main-api-server.mustache", "", modelNamePrefix + "main-api-server.cpp"));
        supportingFiles.add(new SupportingFile("cmake.mustache", "", "CMakeLists.txt"));
        supportingFiles.add(new SupportingFile("README.mustache", "", "README.md"));

@@ -139,6 +139,7 @@ public class CppPistacheServerCodegen extends AbstractCppCodegen {
            supportingFiles.add(new SupportingFile("modelbase-source.mustache", "model", modelNamePrefix + "ModelBase.cpp"));
            supportingFiles.add(new SupportingFile("helpers-header.mustache", "model", modelNamePrefix + "Helpers.h"));
            supportingFiles.add(new SupportingFile("helpers-source.mustache", "model", modelNamePrefix + "Helpers.cpp"));
+            supportingFiles.add(new SupportingFile("main-api-server.mustache", "", modelNamePrefix + "main-api-server.cpp"));
            supportingFiles.add(new SupportingFile("cmake.mustache", "", "CMakeLists.txt"));
            supportingFiles.add(new SupportingFile("README.mustache", "", "README.md"));
        }
@@ -291,10 +292,6 @@ public class CppPistacheServerCodegen extends AbstractCppCodegen {
            int ix = result.lastIndexOf(File.separatorChar);
            result = result.substring(0, ix) + result.substring(ix, result.length() - 4) + "Impl.cpp";
            result = result.replace(apiFileFolder(), implFileFolder());
-        } else if (templateName.endsWith("api-server.mustache")) {
-            int ix = result.lastIndexOf(File.separatorChar);
-            result = result.substring(0, ix) + result.substring(ix, result.length() - 4) + "MainServer.cpp";
-            result = result.replace(apiFileFolder(), outputFolder);
        }
        return result;
    }
--- a/modules/openapi-generator/src/main/java/org/openapitools/codegen/languages/CppRestSdkClientCodegen.java
+++ b/modules/openapi-generator/src/main/java/org/openapitools/codegen/languages/CppRestSdkClientCodegen.java
@@ -38,6 +38,7 @@ import java.util.Arrays;
 import java.util.Collection;
 import java.util.HashMap;
 import java.util.HashSet;
+import java.util.List;
 import java.util.Locale;
 import java.util.Map;
 import java.util.Set;
@@ -154,7 +155,7 @@ public class CppRestSdkClientCodegen extends AbstractCppCodegen {
        typeMapping.put("map", "std::map");
        typeMapping.put("file", "HttpContent");
        typeMapping.put("object", "Object");
-        typeMapping.put("binary", "std::string");
+        typeMapping.put("binary", "utility::string_t");
        typeMapping.put("number", "double");
        typeMapping.put("UUID", "utility::string_t");
        typeMapping.put("ByteArray", "utility::string_t");
@@ -249,6 +250,7 @@ public class CppRestSdkClientCodegen extends AbstractCppCodegen {

            if (methodResponse != null) {
                Schema response = ModelUtils.getSchemaFromResponse(methodResponse);
+                response = ModelUtils.unaliasSchema(openAPI.getComponents().getSchemas(), response);
                if (response != null) {
                    CodegenProperty cm = fromProperty("response", response);
                    op.vendorExtensions.put("x-codegen-response", cm);
@@ -276,6 +278,24 @@ public class CppRestSdkClientCodegen extends AbstractCppCodegen {
        }
    }

+    // override with any special post-processing
+    @SuppressWarnings("unchecked")
+    @Override
+    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");
+        for (CodegenOperation op : operationList) {
+            for(String hdr : op.imports) {
+                if(importMapping.containsKey(hdr)) {
+                    continue;
+                }
+                operations.put("hasModelImport", true);
+                break;
+            }
+        }
+        return objs;
+    }
+    
    protected boolean isFileSchema(CodegenProperty property) {
        return property.baseType.equals("HttpContent");
    }
--- a/modules/openapi-generator/src/main/java/org/openapitools/codegen/languages/ElmClientCodegen.java
+++ b/modules/openapi-generator/src/main/java/org/openapitools/codegen/languages/ElmClientCodegen.java
@@ -59,8 +59,10 @@ public class ElmClientCodegen extends DefaultCodegen implements CodegenConfig {
    private static final Logger LOGGER = LoggerFactory.getLogger(ElmClientCodegen.class);
    private Set<String> customPrimitives = new HashSet<String>();
    private ElmVersion elmVersion = ElmVersion.ELM_019;
+    private Boolean elmPrefixCustomTypeVariants = false;

    private static final String ELM_VERSION = "elmVersion";
+    private static final String ELM_PREFIX_CUSTOM_TYPE_VARIANTS = "elmPrefixCustomTypeVariants";
    private static final String ENCODER = "elmEncoder";
    private static final String DECODER = "elmDecoder";
    private static final String DISCRIMINATOR_NAME = "discriminatorName";
@@ -162,13 +164,14 @@ public class ElmClientCodegen extends DefaultCodegen implements CodegenConfig {
        supportedVersions.put("0.19", "Elm 0.19");
        elmVersion.setEnum(supportedVersions);
        cliOptions.add(elmVersion);
+        final CliOption elmPrefixCustomTypeVariants = CliOption.newBoolean(ELM_PREFIX_CUSTOM_TYPE_VARIANTS, "Prefix custom type variants");
+        cliOptions.add(elmPrefixCustomTypeVariants);
    }

    @Override
    public void processOpts() {
        super.processOpts();

-
        if (additionalProperties.containsKey(ELM_VERSION)) {
            final String version = (String) additionalProperties.get(ELM_VERSION);
            if ("0.18".equals(version)) {
@@ -178,6 +181,10 @@ public class ElmClientCodegen extends DefaultCodegen implements CodegenConfig {
            }
        }

+        if (additionalProperties.containsKey(ELM_PREFIX_CUSTOM_TYPE_VARIANTS)) {
+            elmPrefixCustomTypeVariants = Boolean.TRUE.equals(Boolean.valueOf(additionalProperties.get(ELM_PREFIX_CUSTOM_TYPE_VARIANTS).toString()));
+        }
+
        if (StringUtils.isEmpty(System.getenv("ELM_POST_PROCESS_FILE"))) {
            if (elmVersion.equals(ElmVersion.ELM_018)) { // 0.18
                LOGGER.info("Environment variable ELM_POST_PROCESS_FILE not defined so the Elm code may not be properly formatted. To define it, try `export ELM_POST_PROCESS_FILE=\"/usr/local/bin/elm-format --elm-version={} --yes\"` (Linux/Mac)", "0.18");
@@ -188,7 +195,7 @@ public class ElmClientCodegen extends DefaultCodegen implements CodegenConfig {

        switch (elmVersion) {
            case ELM_018:
-                LOGGER.info("Elm version = 0.18");
+                LOGGER.info("Elm version: 0.18");
                additionalProperties.put("isElm018", true);
                supportingFiles.add(new SupportingFile("DateOnly018.mustache", "src", "DateOnly.elm"));
                supportingFiles.add(new SupportingFile("DateTime018.mustache", "src", "DateTime.elm"));
@@ -196,7 +203,7 @@ public class ElmClientCodegen extends DefaultCodegen implements CodegenConfig {
                supportingFiles.add(new SupportingFile("Main018.mustache", "src", "Main.elm"));
                break;
            case ELM_019:
-                LOGGER.info("Elm version = 0.19");
+                LOGGER.info("Elm version: 0.19");
                additionalProperties.put("isElm019", true);
                supportingFiles.add(new SupportingFile("DateOnly.mustache", "src", "DateOnly.elm"));
                supportingFiles.add(new SupportingFile("DateTime.mustache", "src", "DateTime.elm"));
@@ -590,6 +597,28 @@ public class ElmClientCodegen extends DefaultCodegen implements CodegenConfig {
        addEncoderAndDecoder(parameter.vendorExtensions, parameter.dataType, isPrimitiveType ? DataTypeExposure.PRIMITIVE : DataTypeExposure.EXTERNAL);
    }

+    @Override
+    public void updateCodegenPropertyEnum(final CodegenProperty property) {
+        super.updateCodegenPropertyEnum(property);
+        if (!elmPrefixCustomTypeVariants) {
+            return;
+        }
+
+        final Map<String, Object> allowableValues = property.allowableValues;
+        if (allowableValues == null) {
+            return;
+        }
+
+        final List<Map<String, Object>> enumVars = (ArrayList<Map<String, Object>>) allowableValues.get("enumVars");
+        if (enumVars == null) {
+            return;
+        }
+        final String prefix = toEnumName(property);
+        for (Map<String, Object> enumVar : enumVars) {
+            enumVar.put("name", prefix + enumVar.get("name"));
+        }
+    }
+
    private boolean isPrimitiveDataType(String dataType) {
        return languageSpecificPrimitives.contains(dataType);
    }
--- a/modules/openapi-generator/src/main/java/org/openapitools/codegen/languages/ErlangServerCodegen.java
+++ b/modules/openapi-generator/src/main/java/org/openapitools/codegen/languages/ErlangServerCodegen.java
@@ -40,6 +40,7 @@ public class ErlangServerCodegen extends DefaultCodegen implements CodegenConfig
    protected String apiVersion = "1.0.0";
    protected String apiPath = "src";
    protected String packageName = "openapi";
+    protected String openApiSpecName = "openapi";

    public ErlangServerCodegen() {
        super();
@@ -47,13 +48,6 @@ public class ErlangServerCodegen extends DefaultCodegen implements CodegenConfig
        // set the output folder here
        outputFolder = "generated-code/erlang-server";

-        if (additionalProperties.containsKey(CodegenConstants.PACKAGE_NAME)) {
-            setPackageName((String) additionalProperties.get(CodegenConstants.PACKAGE_NAME));
-        } else {
-            additionalProperties.put(CodegenConstants.PACKAGE_NAME, packageName);
-        }
-        ;
-
        /**
         * Models.  You can write model files using the modelTemplateFiles map.
         * if you want to create one template for file, you can do so here.
@@ -117,6 +111,27 @@ public class ErlangServerCodegen extends DefaultCodegen implements CodegenConfig
        cliOptions.clear();
        cliOptions.add(new CliOption(CodegenConstants.PACKAGE_NAME, "Erlang package name (convention: lowercase).")
                .defaultValue(this.packageName));
+
+        cliOptions.add(new CliOption(CodegenConstants.OPEN_API_SPEC_NAME, "Openapi Spec Name.")
+                .defaultValue(this.openApiSpecName));
+    }
+
+    @Override
+    public void processOpts() {
+        super.processOpts();
+
+        if (additionalProperties.containsKey(CodegenConstants.PACKAGE_NAME)) {
+            setPackageName((String) additionalProperties.get(CodegenConstants.PACKAGE_NAME));
+        } else {
+            additionalProperties.put(CodegenConstants.PACKAGE_NAME, packageName);
+        }
+
+        if (additionalProperties.containsKey(CodegenConstants.OPEN_API_SPEC_NAME)) {
+            setOpenApiSpecName((String) additionalProperties.get(CodegenConstants.OPEN_API_SPEC_NAME));
+        } else {
+            additionalProperties.put(CodegenConstants.OPEN_API_SPEC_NAME, openApiSpecName);
+        }
+
        /**
         * Additional Properties.  These values can be passed to the templates and
         * are available in models, apis, and supporting files
@@ -135,7 +150,7 @@ public class ErlangServerCodegen extends DefaultCodegen implements CodegenConfig
        supportingFiles.add(new SupportingFile("server.mustache", "", toSourceFilePath("server", "erl")));
        supportingFiles.add(new SupportingFile("utils.mustache", "", toSourceFilePath("utils", "erl")));
        supportingFiles.add(new SupportingFile("auth.mustache", "", toSourceFilePath("auth", "erl")));
-        supportingFiles.add(new SupportingFile("openapi.mustache", "", toPrivFilePath("openapi", "json")));
+        supportingFiles.add(new SupportingFile("openapi.mustache", "", toPrivFilePath(this.openApiSpecName, "json")));
        supportingFiles.add(new SupportingFile("default_logic_handler.mustache", "", toSourceFilePath("default_logic_handler", "erl")));
        supportingFiles.add(new SupportingFile("logic_handler.mustache", "", toSourceFilePath("logic_handler", "erl")));
        writeOptional(outputFolder, new SupportingFile("README.mustache", "", "README.md"));
@@ -254,6 +269,10 @@ public class ErlangServerCodegen extends DefaultCodegen implements CodegenConfig
        this.packageName = packageName;
    }

+    public void setOpenApiSpecName(String openApiSpecName) {
+        this.openApiSpecName = openApiSpecName;
+    }
+
    protected String toHandlerName(String name) {
        return toModuleName(name) + "_handler";
    }
--- a/modules/openapi-generator/src/main/java/org/openapitools/codegen/languages/JavaClientCodegen.java
+++ b/modules/openapi-generator/src/main/java/org/openapitools/codegen/languages/JavaClientCodegen.java
@@ -269,10 +269,13 @@ public class JavaClientCodegen extends AbstractJavaCodegen
            apiDocTemplateFiles.remove("api_doc.mustache");
        }

-        if (!(FEIGN.equals(getLibrary()) || RESTTEMPLATE.equals(getLibrary()) || usesAnyRetrofitLibrary() || GOOGLE_API_CLIENT.equals(getLibrary()) || REST_ASSURED.equals(getLibrary()))) {
+        if (!(FEIGN.equals(getLibrary()) || RESTTEMPLATE.equals(getLibrary()) || usesAnyRetrofitLibrary() || GOOGLE_API_CLIENT.equals(getLibrary()) || REST_ASSURED.equals(getLibrary()) || WEBCLIENT.equals(getLibrary()))) {
            supportingFiles.add(new SupportingFile("apiException.mustache", invokerFolder, "ApiException.java"));
            supportingFiles.add(new SupportingFile("Configuration.mustache", invokerFolder, "Configuration.java"));
            supportingFiles.add(new SupportingFile("Pair.mustache", invokerFolder, "Pair.java"));
+        }
+
+        if (!(FEIGN.equals(getLibrary()) || RESTTEMPLATE.equals(getLibrary()) || usesAnyRetrofitLibrary() || GOOGLE_API_CLIENT.equals(getLibrary()) || REST_ASSURED.equals(getLibrary()))) {
            supportingFiles.add(new SupportingFile("auth/Authentication.mustache", authFolder, "Authentication.java"));
        }

--- a/modules/openapi-generator/src/main/java/org/openapitools/codegen/languages/RustClientCodegen.java
+++ b/modules/openapi-generator/src/main/java/org/openapitools/codegen/languages/RustClientCodegen.java
@@ -17,27 +17,17 @@

 package org.openapitools.codegen.languages;

+import com.google.common.base.Strings;
 import io.swagger.v3.oas.models.media.ArraySchema;
 import io.swagger.v3.oas.models.media.Schema;
-import org.apache.commons.lang3.StringUtils;
-import org.openapitools.codegen.CliOption;
-import org.openapitools.codegen.CodegenConfig;
-import org.openapitools.codegen.CodegenConstants;
-import org.openapitools.codegen.CodegenOperation;
-import org.openapitools.codegen.CodegenProperty;
-import org.openapitools.codegen.CodegenType;
-import org.openapitools.codegen.DefaultCodegen;
-import org.openapitools.codegen.SupportingFile;
+import org.openapitools.codegen.*;
 import org.openapitools.codegen.utils.ModelUtils;
+import org.openapitools.codegen.utils.StringUtils;
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;

 import java.io.File;
-import java.util.Arrays;
-import java.util.HashSet;
-import java.util.List;
-import java.util.Locale;
-import java.util.Map;
+import java.util.*;


 public class RustClientCodegen extends DefaultCodegen implements CodegenConfig {
@@ -45,6 +35,9 @@ public class RustClientCodegen extends DefaultCodegen implements CodegenConfig {
    public static final String PACKAGE_NAME = "packageName";
    public static final String PACKAGE_VERSION = "packageVersion";

+    public static final String HYPER_LIBRARY = "hyper";
+    public static final String REQWEST_LIBRARY = "reqwest";
+
    protected String packageName = "openapi";
    protected String packageVersion = "1.0.0";
    protected String apiDocPath = "docs/";
@@ -68,7 +61,6 @@ public class RustClientCodegen extends DefaultCodegen implements CodegenConfig {
        super();
        outputFolder = "generated-code/rust";
        modelTemplateFiles.put("model.mustache", ".rs");
-        apiTemplateFiles.put("api.mustache", ".rs");

        modelDocTemplateFiles.put("model_doc.mustache", ".md");
        apiDocTemplateFiles.put("api_doc.mustache", ".md");
@@ -141,6 +133,15 @@ public class RustClientCodegen extends DefaultCodegen implements CodegenConfig {
        cliOptions.add(new CliOption(CodegenConstants.HIDE_GENERATION_TIMESTAMP, CodegenConstants.HIDE_GENERATION_TIMESTAMP_DESC)
                .defaultValue(Boolean.TRUE.toString()));

+        supportedLibraries.put(HYPER_LIBRARY, "HTTP client: Hyper.");
+        supportedLibraries.put(REQWEST_LIBRARY, "HTTP client: Reqwest.");
+
+        CliOption libraryOption = new CliOption(CodegenConstants.LIBRARY, "library template (sub-template) to use.");
+        libraryOption.setEnum(supportedLibraries);
+        // set hyper as the default
+        libraryOption.setDefault(HYPER_LIBRARY);
+        cliOptions.add(libraryOption);
+        setLibrary(HYPER_LIBRARY);
    }

    @Override
@@ -165,21 +166,34 @@ public class RustClientCodegen extends DefaultCodegen implements CodegenConfig {
        additionalProperties.put("apiDocPath", apiDocPath);
        additionalProperties.put("modelDocPath", modelDocPath);

+        if ( HYPER_LIBRARY.equals(getLibrary())){
+            additionalProperties.put(HYPER_LIBRARY, "true");
+        } else if (REQWEST_LIBRARY.equals(getLibrary())) {
+            additionalProperties.put(REQWEST_LIBRARY, "true");
+        } else {
+            LOGGER.error("Unknown library option (-l/--library): {}", getLibrary());
+        }
+
+        apiTemplateFiles.put(getLibrary() + "/api.mustache", ".rs");
+
        modelPackage = packageName;
        apiPackage = packageName;

        supportingFiles.add(new SupportingFile("README.mustache", "", "README.md"));
        supportingFiles.add(new SupportingFile("git_push.sh.mustache", "", "git_push.sh"));
        supportingFiles.add(new SupportingFile("gitignore.mustache", "", ".gitignore"));
-        supportingFiles.add(new SupportingFile("configuration.mustache", apiFolder, "configuration.rs"));
        supportingFiles.add(new SupportingFile(".travis.yml", "", ".travis.yml"));
-
-        supportingFiles.add(new SupportingFile("api_mod.mustache", apiFolder, "mod.rs"));
-        supportingFiles.add(new SupportingFile("client.mustache", apiFolder, "client.rs"));
-        supportingFiles.add(new SupportingFile("request.rs", apiFolder, "request.rs"));
        supportingFiles.add(new SupportingFile("model_mod.mustache", modelFolder, "mod.rs"));
-        supportingFiles.add(new SupportingFile("lib.rs", "src", "lib.rs"));
+        supportingFiles.add(new SupportingFile("lib.mustache", "src", "lib.rs"));
        supportingFiles.add(new SupportingFile("Cargo.mustache", "", "Cargo.toml"));
+
+        if (HYPER_LIBRARY.equals(getLibrary())) {
+            supportingFiles.add(new SupportingFile("request.rs", apiFolder, "request.rs"));
+        }
+
+        supportingFiles.add(new SupportingFile(getLibrary() + "/configuration.mustache", apiFolder, "configuration.rs"));
+        supportingFiles.add(new SupportingFile(getLibrary() + "/client.mustache", apiFolder, "client.rs"));
+        supportingFiles.add(new SupportingFile(getLibrary() + "/api_mod.mustache", apiFolder, "mod.rs"));
    }

    @Override
@@ -209,7 +223,7 @@ public class RustClientCodegen extends DefaultCodegen implements CodegenConfig {
            return name;

        // snake_case, e.g. PetId => pet_id
-        name = org.openapitools.codegen.utils.StringUtils.underscore(name);
+        name = StringUtils.underscore(name);

        // for reserved word or word starting with number, append _
        if (isReservedWord(name))
@@ -231,16 +245,17 @@ public class RustClientCodegen extends DefaultCodegen implements CodegenConfig {
    public String toModelName(String name) {
        // camelize the model name
        // phone_number => PhoneNumber
-        return org.openapitools.codegen.utils.StringUtils.camelize(toModelFilename(name));
+        return StringUtils.camelize(toModelFilename(name));
    }

    @Override
    public String toModelFilename(String name) {
-        if (!StringUtils.isEmpty(modelNamePrefix)) {
+
+        if (!Strings.isNullOrEmpty(modelNamePrefix)) {
            name = modelNamePrefix + "_" + name;
        }

-        if (!StringUtils.isEmpty(modelNameSuffix)) {
+        if (!Strings.isNullOrEmpty(modelNameSuffix)) {
            name = name + "_" + modelNameSuffix;
        }

@@ -258,7 +273,7 @@ public class RustClientCodegen extends DefaultCodegen implements CodegenConfig {
            name = "model_" + name; // e.g. 200Response => Model200Response (after camelize)
        }

-        return org.openapitools.codegen.utils.StringUtils.underscore(name);
+        return StringUtils.underscore(name);
    }

    @Override
@@ -267,7 +282,7 @@ public class RustClientCodegen extends DefaultCodegen implements CodegenConfig {
        name = name.replaceAll("-", "_"); // FIXME: a parameter should not be assigned. Also declare the methods parameters as 'final'.

        // e.g. PetApi.rs => pet_api.rs
-        return org.openapitools.codegen.utils.StringUtils.underscore(name) + "_api";
+        return StringUtils.underscore(name) + "_api";
    }

    @Override
@@ -340,11 +355,11 @@ public class RustClientCodegen extends DefaultCodegen implements CodegenConfig {

        // method name cannot use reserved keyword, e.g. return
        if (isReservedWord(sanitizedOperationId)) {
-            LOGGER.warn(operationId + " (reserved word) cannot be used as method name. Renamed to " + org.openapitools.codegen.utils.StringUtils.underscore("call_" + operationId));
+            LOGGER.warn(operationId + " (reserved word) cannot be used as method name. Renamed to " + StringUtils.underscore("call_" + operationId));
            sanitizedOperationId = "call_" + sanitizedOperationId;
        }

-        return org.openapitools.codegen.utils.StringUtils.underscore(sanitizedOperationId);
+        return StringUtils.underscore(sanitizedOperationId);
    }

    @Override
@@ -353,9 +368,15 @@ public class RustClientCodegen extends DefaultCodegen implements CodegenConfig {
        Map<String, Object> objectMap = (Map<String, Object>) objs.get("operations");
        @SuppressWarnings("unchecked")
        List<CodegenOperation> operations = (List<CodegenOperation>) objectMap.get("operation");
+        Set<String> headerKeys = new HashSet<>();
        for (CodegenOperation operation : operations) {
-            // http method verb conversion (e.g. PUT => Put)
-            operation.httpMethod = org.openapitools.codegen.utils.StringUtils.camelize(operation.httpMethod.toLowerCase(Locale.ROOT));
+            // http method verb conversion, depending on client library (e.g. Hyper: PUT => Put, Reqwest: PUT => put)
+            if (HYPER_LIBRARY.equals(getLibrary())) {
+                operation.httpMethod = StringUtils.camelize(operation.httpMethod.toLowerCase(Locale.ROOT));
+            } else if (REQWEST_LIBRARY.equals(getLibrary())) {
+                operation.httpMethod = operation.httpMethod.toLowerCase(Locale.ROOT);
+            }
+
            // update return type to conform to rust standard
            /*
            if (operation.returnType != null) {
@@ -407,6 +428,9 @@ public class RustClientCodegen extends DefaultCodegen implements CodegenConfig {
            }*/
        }

+        additionalProperties.put("headerKeys", headerKeys);
+        additionalProperties.putIfAbsent("authHeaderKey", "api-key");
+
        return objs;
    }

--- a/modules/openapi-generator/src/main/java/org/openapitools/codegen/languages/SpringCodegen.java
+++ b/modules/openapi-generator/src/main/java/org/openapitools/codegen/languages/SpringCodegen.java
@@ -34,6 +34,7 @@ import org.openapitools.codegen.CodegenType;
 import org.openapitools.codegen.SupportingFile;
 import org.openapitools.codegen.languages.features.BeanValidationFeatures;
 import org.openapitools.codegen.languages.features.OptionalFeatures;
+import org.openapitools.codegen.languages.features.PerformBeanValidationFeatures;
 import org.openapitools.codegen.utils.URLPathUtils;
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
@@ -51,7 +52,8 @@ import java.util.stream.Collectors;


 public class SpringCodegen extends AbstractJavaCodegen
-        implements BeanValidationFeatures, OptionalFeatures {
+        implements BeanValidationFeatures, PerformBeanValidationFeatures,
+        OptionalFeatures {
    private static final Logger LOGGER = LoggerFactory.getLogger(SpringCodegen.class);

    public static final String TITLE = "title";
@@ -74,6 +76,7 @@ public class SpringCodegen extends AbstractJavaCodegen
    public static final String IMPLICIT_HEADERS = "implicitHeaders";
    public static final String OPENAPI_DOCKET_CONFIG = "swaggerDocketConfig";
    public static final String API_FIRST = "apiFirst";
+    public static final String HATEOAS = "hateoas";

    protected String title = "OpenAPI Spring";
    protected String configPackage = "org.openapitools.configuration";
@@ -88,11 +91,13 @@ public class SpringCodegen extends AbstractJavaCodegen
    protected String responseWrapper = "";
    protected boolean useTags = false;
    protected boolean useBeanValidation = true;
+    protected boolean performBeanValidation = false;
    protected boolean implicitHeaders = false;
    protected boolean openapiDocketConfig = false;
    protected boolean apiFirst = false;
    protected boolean useOptional = false;
    protected boolean virtualService = false;
+    protected boolean hateoas = false;

    public SpringCodegen() {
        super();
@@ -120,10 +125,12 @@ public class SpringCodegen extends AbstractJavaCodegen
        cliOptions.add(CliOption.newBoolean(VIRTUAL_SERVICE, "Generates the virtual service. For more details refer - https://github.com/elan-venture/virtualan/wiki"));
        cliOptions.add(CliOption.newBoolean(USE_TAGS, "use tags for creating interface and controller classnames", useTags));
        cliOptions.add(CliOption.newBoolean(USE_BEANVALIDATION, "Use BeanValidation API annotations", useBeanValidation));
+        cliOptions.add(CliOption.newBoolean(PERFORM_BEANVALIDATION, "Use Bean Validation Impl. to perform BeanValidation", performBeanValidation));
        cliOptions.add(CliOption.newBoolean(IMPLICIT_HEADERS, "Use of @ApiImplicitParams for headers.", implicitHeaders));
        cliOptions.add(CliOption.newBoolean(OPENAPI_DOCKET_CONFIG, "Generate Spring OpenAPI Docket configuration class.", openapiDocketConfig));
        cliOptions.add(CliOption.newBoolean(API_FIRST, "Generate the API from the OAI spec at server compile time (API first approach)", apiFirst));
        cliOptions.add(CliOption.newBoolean(USE_OPTIONAL,"Use Optional container for optional parameters", useOptional));
+        cliOptions.add(CliOption.newBoolean(HATEOAS, "Use Spring HATEOAS library to allow adding HATEOAS links", hateoas));

        supportedLibraries.put(SPRING_BOOT, "Spring-boot Server application using the SpringFox integration.");
        supportedLibraries.put(SPRING_MVC_LIBRARY, "Spring-MVC Server application using the SpringFox integration.");
@@ -245,6 +252,11 @@ public class SpringCodegen extends AbstractJavaCodegen
        }
        writePropertyBack(USE_BEANVALIDATION, useBeanValidation);

+        if (additionalProperties.containsKey(PERFORM_BEANVALIDATION)) {
+            this.setPerformBeanValidation(convertPropertyToBoolean(PERFORM_BEANVALIDATION));
+        }
+        writePropertyBack(PERFORM_BEANVALIDATION, performBeanValidation);
+
        if (additionalProperties.containsKey(USE_OPTIONAL)) {
            this.setUseOptional(convertPropertyToBoolean(USE_OPTIONAL));
        }
@@ -260,6 +272,10 @@ public class SpringCodegen extends AbstractJavaCodegen
        if (additionalProperties.containsKey(API_FIRST)) {
            this.setApiFirst(Boolean.valueOf(additionalProperties.get(API_FIRST).toString()));
        }
+        
+        if (additionalProperties.containsKey(HATEOAS)) {
+            this.setHateoas(Boolean.valueOf(additionalProperties.get(HATEOAS).toString()));
+        }

        typeMapping.put("file", "Resource");
        importMapping.put("Resource", "org.springframework.core.io.Resource");
@@ -700,6 +716,10 @@ public class SpringCodegen extends AbstractJavaCodegen
    public void setApiFirst(boolean apiFirst) {
        this.apiFirst = apiFirst;
    }
+    
+    public void setHateoas(boolean hateoas) {
+        this.hateoas = hateoas;
+    }

    @Override
    public void postProcessModelProperty(CodegenModel model, CodegenProperty property) {
@@ -750,6 +770,10 @@ public class SpringCodegen extends AbstractJavaCodegen
        this.useBeanValidation = useBeanValidation;
    }

+    public void setPerformBeanValidation(boolean performBeanValidation) {
+        this.performBeanValidation = performBeanValidation;
+    }
+
    @Override
    public void setUseOptional(boolean useOptional) {
        this.useOptional = useOptional;
--- a/modules/openapi-generator/src/main/java/org/openapitools/codegen/languages/StaticHtmlGenerator.java
+++ b/modules/openapi-generator/src/main/java/org/openapitools/codegen/languages/StaticHtmlGenerator.java
@@ -69,7 +69,7 @@ public class StaticHtmlGenerator extends DefaultCodegen implements CodegenConfig

        additionalProperties.put("appName", "OpenAPI Sample");
        additionalProperties.put("appDescription", "A sample OpenAPI server");
-        additionalProperties.put("infoUrl", "https//openapi-generator.tech");
+        additionalProperties.put("infoUrl", "https://openapi-generator.tech");
        additionalProperties.put("infoEmail", "team@openapitools.org");
        additionalProperties.put("licenseInfo", "All rights reserved");
        additionalProperties.put("licenseUrl", "http://apache.org/licenses/LICENSE-2.0.html");
--- a/modules/openapi-generator/src/main/java/org/openapitools/codegen/utils/ModelUtils.java
+++ b/modules/openapi-generator/src/main/java/org/openapitools/codegen/utils/ModelUtils.java
@@ -20,6 +20,7 @@ package org.openapitools.codegen.utils;
 import io.swagger.v3.oas.models.OpenAPI;
 import io.swagger.v3.oas.models.Operation;
 import io.swagger.v3.oas.models.PathItem;
+import io.swagger.v3.oas.models.callbacks.Callback;
 import io.swagger.v3.oas.models.headers.Header;
 import io.swagger.v3.oas.models.media.ArraySchema;
 import io.swagger.v3.oas.models.media.BinarySchema;
@@ -167,40 +168,56 @@ public class ModelUtils {

        if (paths != null) {
            for (PathItem path : paths.values()) {
-                List<Operation> allOperations = path.readOperations();
-                if (allOperations != null) {
-                    for (Operation operation : allOperations) {
-                        //Params:
-                        if (operation.getParameters() != null) {
-                            for (Parameter p : operation.getParameters()) {
-                                Parameter parameter = getReferencedParameter(openAPI, p);
-                                if (parameter.getSchema() != null) {
-                                    visitSchema(openAPI, parameter.getSchema(), null, visitedSchemas, visitor);
-                                }
-                            }
-                        }
+                visitPathItem(path, openAPI, visitor, visitedSchemas);
+            }
+        }
+    }

-                        //RequestBody:
-                        RequestBody requestBody = getReferencedRequestBody(openAPI, operation.getRequestBody());
-                        if (requestBody != null && requestBody.getContent() != null) {
-                            for (Entry<String, MediaType> e : requestBody.getContent().entrySet()) {
+    private static void visitPathItem(PathItem pathItem, OpenAPI openAPI, OpenAPISchemaVisitor visitor, List<String> visitedSchemas) {
+        List<Operation> allOperations = pathItem.readOperations();
+        if (allOperations != null) {
+            for (Operation operation : allOperations) {
+                //Params:
+                if (operation.getParameters() != null) {
+                    for (Parameter p : operation.getParameters()) {
+                        Parameter parameter = getReferencedParameter(openAPI, p);
+                        if (parameter.getSchema() != null) {
+                            visitSchema(openAPI, parameter.getSchema(), null, visitedSchemas, visitor);
+                        }
+                    }
+                }
+
+                //RequestBody:
+                RequestBody requestBody = getReferencedRequestBody(openAPI, operation.getRequestBody());
+                if (requestBody != null && requestBody.getContent() != null) {
+                    for (Entry<String, MediaType> e : requestBody.getContent().entrySet()) {
+                        if (e.getValue().getSchema() != null) {
+                            visitSchema(openAPI, e.getValue().getSchema(), e.getKey(), visitedSchemas, visitor);
+                        }
+                    }
+                }
+
+                //Responses:
+                if (operation.getResponses() != null) {
+                    for (ApiResponse r : operation.getResponses().values()) {
+                        ApiResponse apiResponse = getReferencedApiResponse(openAPI, r);
+                        if (apiResponse != null && apiResponse.getContent() != null) {
+                            for (Entry<String, MediaType> e : apiResponse.getContent().entrySet()) {
                                if (e.getValue().getSchema() != null) {
                                    visitSchema(openAPI, e.getValue().getSchema(), e.getKey(), visitedSchemas, visitor);
                                }
                            }
                        }
+                    }
+                }

-                        //Responses:
-                        if (operation.getResponses() != null) {
-                            for (ApiResponse r : operation.getResponses().values()) {
-                                ApiResponse apiResponse = getReferencedApiResponse(openAPI, r);
-                                if (apiResponse != null && apiResponse.getContent() != null) {
-                                    for (Entry<String, MediaType> e : apiResponse.getContent().entrySet()) {
-                                        if (e.getValue().getSchema() != null) {
-                                            visitSchema(openAPI, e.getValue().getSchema(), e.getKey(), visitedSchemas, visitor);
-                                        }
-                                    }
-                                }
+                //Callbacks:
+                if (operation.getCallbacks() != null) {
+                    for (Callback c : operation.getCallbacks().values()) {
+                        Callback callback = getReferencedCallback(openAPI, c);
+                        if (callback != null) {
+                            for (PathItem p : callback.values()) {
+                                visitPathItem(p, openAPI, visitor, visitedSchemas);
                            }
                        }
                    }
@@ -603,6 +620,35 @@ public class ModelUtils {
        return null;
    }

+    /**
+     * If a Callback contains a reference to an other Callback with '$ref', returns the referenced Callback if it is found or the actual Callback in the other cases.
+     *
+     * @param openAPI   specification being checked
+     * @param callback potentially containing a '$ref'
+     * @return callback without '$ref'
+     */
+    public static Callback getReferencedCallback(OpenAPI openAPI, Callback callback) {
+        if (callback != null && StringUtils.isNotEmpty(callback.get$ref())) {
+            String name = getSimpleRef(callback.get$ref());
+            Callback referencedCallback = getCallback(openAPI, name);
+            if (referencedCallback != null) {
+                return referencedCallback;
+            }
+        }
+        return callback;
+    }
+
+    public static Callback getCallback(OpenAPI openAPI, String name) {
+        if (name == null) {
+            return null;
+        }
+        
+        if (openAPI != null && openAPI.getComponents() != null && openAPI.getComponents().getCallbacks() != null) {
+            return openAPI.getComponents().getCallbacks().get(name);
+        }
+        return null;
+    }
+
    /**
     * Return the first defined Schema for a RequestBody
     *
--- a/modules/openapi-generator/src/main/java/org/openapitools/codegen/utils/URLPathUtils.java
+++ b/modules/openapi-generator/src/main/java/org/openapitools/codegen/utils/URLPathUtils.java
@@ -168,7 +168,7 @@ public class URLPathUtils {
     */
    public static String getHost(OpenAPI openAPI) {
        if (openAPI.getServers() != null && openAPI.getServers().size() > 0) {
-            return sanitizeUrl(openAPI.getServers().get(0).getUrl());
+            return sanitizeUrl(getServerURL(openAPI.getServers().get(0)).toString());
        }
        return LOCAL_HOST;
    }