[Java] Replace "useNullForUnknownEnumValue" option with the nullable attribute (#3455)

* add nullable support to enum

* update test spec with nullable enum

* update samples

* update samples

bin/java-petstore-jersey1.sh

@@ -27,7 +27,7 @@ fi
 
 # if you've executed sbt assembly previously it will use that instead.
 export JAVA_OPTS="${JAVA_OPTS} -Xmx1024M -DloggerPath=conf/log4j.properties"
-ags="generate --artifact-id petstore-java-client-jersey1 -t modules/openapi-generator/src/main/resources/Java -i modules/openapi-generator/src/test/resources/2_0/petstore-with-fake-endpoints-models-for-testing.yaml -g java -o samples/client/petstore/java/jersey1 --additional-properties hideGenerationTimestamp=true --library=jersey1 --additional-properties useNullForUnknownEnumValue=true $@"
+ags="generate --artifact-id petstore-java-client-jersey1 -t modules/openapi-generator/src/main/resources/Java -i modules/openapi-generator/src/test/resources/2_0/petstore-with-fake-endpoints-models-for-testing.yaml -g java -o samples/client/petstore/java/jersey1 --additional-properties hideGenerationTimestamp=true --library=jersey1 $@"
 
 echo "Removing files and folders under samples/client/petstore/java/jersey1/src/main"
 rm -rf samples/client/petstore/java/jersey1/src/main

bin/java-petstore-jersey2.json

@@ -1,7 +1,4 @@
 {
     "library": "jersey2",
-    "artifactId": "petstore-jersey2",
-        "additionalProperties" : {
-            "useNullForUnknownEnumValue" : true
-        }
+    "artifactId": "petstore-jersey2"
 }

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

@@ -61,7 +61,7 @@ public class CodegenModel {
     public Set<String> allMandatory = new TreeSet<String>(); // with parent's required properties
 
     public Set<String> imports = new TreeSet<String>();
-    public boolean hasVars, emptyVars, hasMoreModels, hasEnums, isEnum, hasRequired, hasOptional, isArrayModel, hasChildren, isMapModel;
+    public boolean hasVars, emptyVars, hasMoreModels, hasEnums, isEnum, isNullable, hasRequired, hasOptional, isArrayModel, hasChildren, isMapModel;
     public boolean hasOnlyReadOnly = true; // true if all properties are read-only
     public ExternalDocumentation externalDocumentation;
 
@@ -118,6 +118,7 @@ public class CodegenModel {
                 .append("hasMoreModels", hasMoreModels)
                 .append("hasEnums", hasEnums)
                 .append("isEnum", isEnum)
+                .append("isNullable", isEnum)
                 .append("hasRequired", hasRequired)
                 .append("hasOptional", hasOptional)
                 .append("isArrayModel", isArrayModel)

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

@@ -1572,7 +1572,7 @@ public class DefaultCodegen implements CodegenConfig {
         } else if (ModelUtils.isURISchema(schema)) {
             return "URI";
         } else if (ModelUtils.isStringSchema(schema)) {
-            if(typeMapping.containsKey(schema.getFormat())) {
+            if (typeMapping.containsKey(schema.getFormat())) {
                 // If the format matches a typeMapping (supplied with the --typeMappings flag)
                 // then treat the format as a primitive type.
                 // This allows the typeMapping flag to add a new custom type which can then
@@ -1884,19 +1884,16 @@ public class DefaultCodegen implements CodegenConfig {
             if (ModelUtils.isMapSchema(schema)) {
                 addAdditionPropertiesToCodeGenModel(m, schema);
                 m.isMapModel = true;
-            }
-            else if (ModelUtils.isIntegerSchema(schema)) { // integer type
+            } else if (ModelUtils.isIntegerSchema(schema)) { // integer type
                 m.isNumeric = Boolean.TRUE;
                 if (ModelUtils.isLongSchema(schema)) { // int64/long format
                     m.isLong = Boolean.TRUE;
                 } else { // int32 format
                     m.isInteger = Boolean.TRUE;
                 }
-            }
-            else if (ModelUtils.isStringSchema(schema)) {
+            } else if (ModelUtils.isStringSchema(schema)) {
                 m.isString = Boolean.TRUE;
-            }
-            else if (ModelUtils.isNumberSchema(schema)) {
+            } else if (ModelUtils.isNumberSchema(schema)) {
                 m.isNumeric = Boolean.TRUE;
                 if (ModelUtils.isFloatSchema(schema)) { // float
                     m.isFloat = Boolean.TRUE;
@@ -1907,6 +1904,10 @@ public class DefaultCodegen implements CodegenConfig {
                 }
             }
 
+            if (Boolean.TRUE.equals(schema.getNullable())) {
+                m.isNullable = Boolean.TRUE;
+            }
+
             // passing null to allProperties and allRequired as there's no parent
             addVars(m, unaliasPropertySchema(schema.getProperties()), schema.getRequired(), null, null);
         }
@@ -3018,7 +3019,7 @@ public class DefaultCodegen implements CodegenConfig {
         }
 
         Schema s;
-        if(parameter.getSchema() != null) {
+        if (parameter.getSchema() != null) {
             s = parameter.getSchema();
         } else if (parameter.getContent() != null) {
             Content content = parameter.getContent();
@@ -4942,7 +4943,7 @@ public class DefaultCodegen implements CodegenConfig {
     }
 
     protected void removeOption(String key) {
-        for(int i = 0; i < cliOptions.size(); i++) {
+        for (int i = 0; i < cliOptions.size(); i++) {
             if (key.equals(cliOptions.get(i).getOpt())) {
                 cliOptions.remove(i);
                 break;

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

@@ -52,7 +52,6 @@ public abstract class AbstractJavaCodegen extends DefaultCodegen implements Code
     public static final String SUPPORT_JAVA6 = "supportJava6";
     public static final String DISABLE_HTML_ESCAPING = "disableHtmlEscaping";
     public static final String BOOLEAN_GETTER_PREFIX = "booleanGetterPrefix";
-    public static final String USE_NULL_FOR_UNKNOWN_ENUM_VALUE = "useNullForUnknownEnumValue";
 
     protected String dateLibrary = "threetenbp";
     protected boolean supportAsync = false;
@@ -86,7 +85,6 @@ public abstract class AbstractJavaCodegen extends DefaultCodegen implements Code
     protected boolean supportJava6 = false;
     protected boolean disableHtmlEscaping = false;
     protected String booleanGetterPrefix = "get";
-    protected boolean useNullForUnknownEnumValue = false;
     protected String parentGroupId = "";
     protected String parentArtifactId = "";
     protected String parentVersion = "";
@@ -220,10 +218,6 @@ 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()));
-        }
-        additionalProperties.put(USE_NULL_FOR_UNKNOWN_ENUM_VALUE, useNullForUnknownEnumValue);
 
         if (additionalProperties.containsKey(CodegenConstants.INVOKER_PACKAGE)) {
             this.setInvokerPackage((String) additionalProperties.get(CodegenConstants.INVOKER_PACKAGE));
@@ -1405,10 +1399,6 @@ public abstract class AbstractJavaCodegen extends DefaultCodegen implements Code
         this.booleanGetterPrefix = booleanGetterPrefix;
     }
 
-    public void setUseNullForUnknownEnumValue(boolean useNullForUnknownEnumValue) {
-        this.useNullForUnknownEnumValue = useNullForUnknownEnumValue;
-    }
-
     @Override
     public String escapeQuotationMark(String input) {
         // remove " to avoid code injection

modules/openapi-generator/src/main/resources/Java/modelEnum.mustache

@@ -53,7 +53,7 @@ public enum {{#datatypeWithEnum}}{{{.}}}{{/datatypeWithEnum}}{{^datatypeWithEnum
         return b;
       }
     }
-    {{#useNullForUnknownEnumValue}}return null;{{/useNullForUnknownEnumValue}}{{^useNullForUnknownEnumValue}}throw new IllegalArgumentException("Unexpected value '" + value + "'");{{/useNullForUnknownEnumValue}}
+    {{#isNullable}}return null;{{/isNullable}}{{^isNullable}}throw new IllegalArgumentException("Unexpected value '" + value + "'");{{/isNullable}}
   }
 {{#gson}}
 

modules/openapi-generator/src/main/resources/Java/modelInnerEnum.mustache

@@ -44,7 +44,7 @@
           return b;
         }
       }
-      {{#useNullForUnknownEnumValue}}return null;{{/useNullForUnknownEnumValue}}{{^useNullForUnknownEnumValue}}throw new IllegalArgumentException("Unexpected value '" + value + "'");{{/useNullForUnknownEnumValue}}
+      {{#isNullable}}return null;{{/isNullable}}{{^isNullable}}throw new IllegalArgumentException("Unexpected value '" + value + "'");{{/isNullable}}
     }
 {{#gson}}
 

modules/openapi-generator/src/main/resources/JavaInflector/enumClass.mustache

@@ -39,6 +39,6 @@
           return b;
         }
       }
-      {{#useNullForUnknownEnumValue}}return null;{{/useNullForUnknownEnumValue}}{{^useNullForUnknownEnumValue}}throw new IllegalArgumentException("Unexpected value '" + text + "'");{{/useNullForUnknownEnumValue}}
+      {{#isNullable}}return null;{{/isNullable}}{{^isNullable}}throw new IllegalArgumentException("Unexpected value '" + text + "'");{{/isNullable}}
     }
   }

modules/openapi-generator/src/main/resources/JavaInflector/enumOuterClass.mustache

@@ -37,6 +37,6 @@ public enum {{#datatypeWithEnum}}{{{.}}}{{/datatypeWithEnum}}{{^datatypeWithEnum
         return b;
       }
     }
-    {{#useNullForUnknownEnumValue}}return null;{{/useNullForUnknownEnumValue}}{{^useNullForUnknownEnumValue}}throw new IllegalArgumentException("Unexpected value '" + text + "'");{{/useNullForUnknownEnumValue}}
+    {{#isNullable}}return null;{{/isNullable}}{{^isNullable}}throw new IllegalArgumentException("Unexpected value '" + text + "'");{{/isNullable}}
   }
 }

modules/openapi-generator/src/main/resources/JavaJaxRS/cxf-cdi/enumClass.mustache

@@ -28,6 +28,6 @@ public enum {{#datatypeWithEnum}}{{{.}}}{{/datatypeWithEnum}}{{^datatypeWithEnum
                 return b;
             }
         }
-        {{#useNullForUnknownEnumValue}}return null;{{/useNullForUnknownEnumValue}}{{^useNullForUnknownEnumValue}}throw new IllegalArgumentException("Unexpected value '" + value + "'");{{/useNullForUnknownEnumValue}}
+        {{#isNullable}}return null;{{/isNullable}}{{^isNullable}}throw new IllegalArgumentException("Unexpected value '" + value + "'");{{/isNullable}}
     }
 }

modules/openapi-generator/src/main/resources/JavaJaxRS/cxf-ext/enumClass.mustache

@@ -28,6 +28,6 @@ public enum {{datatypeWithEnum}} {
                 return b;
             }
         }
-        {{#useNullForUnknownEnumValue}}return null;{{/useNullForUnknownEnumValue}}{{^useNullForUnknownEnumValue}}throw new IllegalArgumentException("Unexpected value '" + value + "'");{{/useNullForUnknownEnumValue}}
+        {{#isNullable}}return null;{{/isNullable}}{{^isNullable}}throw new IllegalArgumentException("Unexpected value '" + value + "'");{{/isNullable}}
     }
 }

modules/openapi-generator/src/main/resources/JavaJaxRS/cxf-ext/enumOuterClass.mustache

@@ -42,7 +42,7 @@ public enum {{#datatypeWithEnum}}{{{.}}}{{/datatypeWithEnum}}{{^datatypeWithEnum
         return b;
       }
     }
-    {{#useNullForUnknownEnumValue}}return null;{{/useNullForUnknownEnumValue}}{{^useNullForUnknownEnumValue}}throw new IllegalArgumentException("Unexpected value '" + value + "'");{{/useNullForUnknownEnumValue}}
+    {{#isNullable}}return null;{{/isNullable}}{{^isNullable}}throw new IllegalArgumentException("Unexpected value '" + value + "'");{{/isNullable}}
   }
   
 }

modules/openapi-generator/src/main/resources/JavaJaxRS/cxf/enumClass.mustache

@@ -28,6 +28,6 @@ public enum {{datatypeWithEnum}} {
                 return b;
             }
         }
-        {{#useNullForUnknownEnumValue}}return null;{{/useNullForUnknownEnumValue}}{{^useNullForUnknownEnumValue}}throw new IllegalArgumentException("Unexpected value '" + value + "'");{{/useNullForUnknownEnumValue}}
+        {{#isNullable}}return null;{{/isNullable}}{{^isNullable}}throw new IllegalArgumentException("Unexpected value '" + value + "'");{{/isNullable}}
     }
 }

modules/openapi-generator/src/main/resources/JavaJaxRS/cxf/enumOuterClass.mustache

@@ -42,7 +42,7 @@ public enum {{#datatypeWithEnum}}{{{.}}}{{/datatypeWithEnum}}{{^datatypeWithEnum
         return b;
       }
     }
-    {{#useNullForUnknownEnumValue}}return null;{{/useNullForUnknownEnumValue}}{{^useNullForUnknownEnumValue}}throw new IllegalArgumentException("Unexpected value '" + value + "'");{{/useNullForUnknownEnumValue}}
+    {{#isNullable}}return null;{{/isNullable}}{{^isNullable}}throw new IllegalArgumentException("Unexpected value '" + value + "'");{{/isNullable}}
   }
   
 }

modules/openapi-generator/src/main/resources/JavaJaxRS/enumClass.mustache

@@ -49,6 +49,6 @@
           return b;
         }
       }
-      {{#useNullForUnknownEnumValue}}return null;{{/useNullForUnknownEnumValue}}{{^useNullForUnknownEnumValue}}throw new IllegalArgumentException("Unexpected value '" + value + "'");{{/useNullForUnknownEnumValue}}
+      {{#isNullable}}return null;{{/isNullable}}{{^isNullable}}throw new IllegalArgumentException("Unexpected value '" + value + "'");{{/isNullable}}
     }
   }

modules/openapi-generator/src/main/resources/JavaJaxRS/enumOuterClass.mustache

@@ -47,6 +47,6 @@ public enum {{#datatypeWithEnum}}{{{.}}}{{/datatypeWithEnum}}{{^datatypeWithEnum
         return b;
       }
     }
-    {{#useNullForUnknownEnumValue}}return null;{{/useNullForUnknownEnumValue}}{{^useNullForUnknownEnumValue}}throw new IllegalArgumentException("Unexpected value '" + value + "'");{{/useNullForUnknownEnumValue}}
+    {{#isNullable}}return null;{{/isNullable}}{{^isNullable}}throw new IllegalArgumentException("Unexpected value '" + value + "'");{{/isNullable}}
   }
 }

modules/openapi-generator/src/main/resources/JavaJaxRS/modelEnum.mustache

@@ -45,7 +45,7 @@ public enum {{#datatypeWithEnum}}{{{.}}}{{/datatypeWithEnum}}{{^datatypeWithEnum
         return b;
       }
     }
-    {{#useNullForUnknownEnumValue}}return null;{{/useNullForUnknownEnumValue}}{{^useNullForUnknownEnumValue}}throw new IllegalArgumentException("Unexpected value '" + value + "'");{{/useNullForUnknownEnumValue}}
+    {{#isNullable}}return null;{{/isNullable}}{{^isNullable}}throw new IllegalArgumentException("Unexpected value '" + value + "'");{{/isNullable}}
   }
 {{/jackson}}
 }

modules/openapi-generator/src/main/resources/JavaJaxRS/spec/enumClass.mustache

@@ -28,6 +28,6 @@ public enum {{datatypeWithEnum}} {
                 return b;
             }
         }
-        {{#useNullForUnknownEnumValue}}return null;{{/useNullForUnknownEnumValue}}{{^useNullForUnknownEnumValue}}throw new IllegalArgumentException("Unexpected value '" + value + "'");{{/useNullForUnknownEnumValue}}
+        {{#isNullable}}return null;{{/isNullable}}{{^isNullable}}throw new IllegalArgumentException("Unexpected value '" + value + "'");{{/isNullable}}
     }
 }

modules/openapi-generator/src/main/resources/JavaJaxRS/spec/enumOuterClass.mustache

@@ -38,6 +38,6 @@ public enum {{#datatypeWithEnum}}{{{.}}}{{/datatypeWithEnum}}{{^datatypeWithEnum
         return b;
       }
     }
-    {{#useNullForUnknownEnumValue}}return null;{{/useNullForUnknownEnumValue}}{{^useNullForUnknownEnumValue}}throw new IllegalArgumentException("Unexpected value '" + value + "'");{{/useNullForUnknownEnumValue}}
+    {{#isNullable}}return null;{{/isNullable}}{{^isNullable}}throw new IllegalArgumentException("Unexpected value '" + value + "'");{{/isNullable}}
   }
 }

modules/openapi-generator/src/main/resources/JavaPlayFramework/enumClass.mustache

@@ -39,6 +39,6 @@
           return b;
         }
       }
-      {{#useNullForUnknownEnumValue}}return null;{{/useNullForUnknownEnumValue}}{{^useNullForUnknownEnumValue}}throw new IllegalArgumentException("Unexpected value '" + value + "'");{{/useNullForUnknownEnumValue}}
+      {{#isNullable}}return null;{{/isNullable}}{{^isNullable}}throw new IllegalArgumentException("Unexpected value '" + value + "'");{{/isNullable}}
     }
   }

modules/openapi-generator/src/main/resources/JavaPlayFramework/enumOuterClass.mustache

@@ -37,6 +37,6 @@ public enum {{#datatypeWithEnum}}{{{.}}}{{/datatypeWithEnum}}{{^datatypeWithEnum
         return b;
       }
     }
-    {{#useNullForUnknownEnumValue}}return null;{{/useNullForUnknownEnumValue}}{{^useNullForUnknownEnumValue}}throw new IllegalArgumentException("Unexpected value '" + value + "'");{{/useNullForUnknownEnumValue}}
+    {{#isNullable}}return null;{{/isNullable}}{{^isNullable}}throw new IllegalArgumentException("Unexpected value '" + value + "'");{{/isNullable}}
   }
 }

modules/openapi-generator/src/main/resources/JavaSpring/enumClass.mustache

@@ -39,6 +39,6 @@
           return b;
         }
       }
-      {{#useNullForUnknownEnumValue}}return null;{{/useNullForUnknownEnumValue}}{{^useNullForUnknownEnumValue}}throw new IllegalArgumentException("Unexpected value '" + value + "'");{{/useNullForUnknownEnumValue}}
+      {{#isNullable}}return null;{{/isNullable}}{{^isNullable}}throw new IllegalArgumentException("Unexpected value '" + value + "'");{{/isNullable}}
     }
   }

modules/openapi-generator/src/main/resources/JavaSpring/enumOuterClass.mustache

@@ -37,6 +37,6 @@ public enum {{#datatypeWithEnum}}{{{.}}}{{/datatypeWithEnum}}{{^datatypeWithEnum
         return b;
       }
     }
-    {{#useNullForUnknownEnumValue}}return null;{{/useNullForUnknownEnumValue}}{{^useNullForUnknownEnumValue}}throw new IllegalArgumentException("Unexpected value '" + value + "'");{{/useNullForUnknownEnumValue}}
+    {{#isNullable}}return null;{{/isNullable}}{{^isNullable}}throw new IllegalArgumentException("Unexpected value '" + value + "'");{{/isNullable}}
   }
 }

modules/openapi-generator/src/main/resources/JavaVertXServer/enumOuterClass.mustache

@@ -31,6 +31,6 @@ public enum {{#datatypeWithEnum}}{{{.}}}{{/datatypeWithEnum}}{{^datatypeWithEnum
         return b;
       }
     }
-    {{#useNullForUnknownEnumValue}}return null;{{/useNullForUnknownEnumValue}}{{^useNullForUnknownEnumValue}}throw new IllegalArgumentException("Unexpected value '" + value + "'");{{/useNullForUnknownEnumValue}}
+    {{#isNullable}}return null;{{/isNullable}}{{^isNullable}}throw new IllegalArgumentException("Unexpected value '" + value + "'");{{/isNullable}}
   }
 }

modules/openapi-generator/src/main/resources/java-msf4j-server/enumClass.mustache

@@ -39,6 +39,6 @@
           return b;
         }
       }
-      {{#useNullForUnknownEnumValue}}return null;{{/useNullForUnknownEnumValue}}{{^useNullForUnknownEnumValue}}throw new IllegalArgumentException("Unexpected value '" + text + "'");{{/useNullForUnknownEnumValue}}
+      {{#isNullable}}return null;{{/isNullable}}{{^isNullable}}throw new IllegalArgumentException("Unexpected value '" + text + "'");{{/isNullable}}
     }
   }

modules/openapi-generator/src/main/resources/java-msf4j-server/enumOuterClass.mustache

@@ -37,6 +37,6 @@ public enum {{#datatypeWithEnum}}{{{.}}}{{/datatypeWithEnum}}{{^datatypeWithEnum
         return b;
       }
     }
-    {{#useNullForUnknownEnumValue}}return null;{{/useNullForUnknownEnumValue}}{{^useNullForUnknownEnumValue}}throw new IllegalArgumentException("Unexpected value '" + text + "'");{{/useNullForUnknownEnumValue}}
+    {{#isNullable}}return null;{{/isNullable}}{{^isNullable}}throw new IllegalArgumentException("Unexpected value '" + text + "'");{{/isNullable}}
   }
 }

modules/openapi-generator/src/main/resources/java-pkmst/enumClass.mustache

@@ -39,6 +39,6 @@
           return b;
         }
       }
-      {{#useNullForUnknownEnumValue}}return null;{{/useNullForUnknownEnumValue}}{{^useNullForUnknownEnumValue}}throw new IllegalArgumentException("Unexpected value '" + text + "'");{{/useNullForUnknownEnumValue}}
+      {{#isNullable}}return null;{{/isNullable}}{{^isNullable}}throw new IllegalArgumentException("Unexpected value '" + text + "'");{{/isNullable}}
     }
   }

modules/openapi-generator/src/main/resources/java-pkmst/enumOuterClass.mustache

@@ -37,6 +37,6 @@ public enum {{#datatypeWithEnum}}{{{.}}}{{/datatypeWithEnum}}{{^datatypeWithEnum
         return b;
       }
     }
-    {{#useNullForUnknownEnumValue}}return null;{{/useNullForUnknownEnumValue}}{{^useNullForUnknownEnumValue}}throw new IllegalArgumentException("Unexpected value '" + text + "'");{{/useNullForUnknownEnumValue}}
+    {{#isNullable}}return null;{{/isNullable}}{{^isNullable}}throw new IllegalArgumentException("Unexpected value '" + text + "'");{{/isNullable}}
   }
 }

modules/openapi-generator/src/main/resources/java-undertow-server/enumOuterClass.mustache

@@ -37,6 +37,6 @@ if (String.valueOf(b.value).equals(text)) {
 return b;
 }
 }
-{{#useNullForUnknownEnumValue}}return null;{{/useNullForUnknownEnumValue}}{{^useNullForUnknownEnumValue}}throw new IllegalArgumentException("Unexpected value '" + text + "'");{{/useNullForUnknownEnumValue}}
+{{#isNullable}}return null;{{/isNullable}}{{^isNullable}}throw new IllegalArgumentException("Unexpected value '" + text + "'");{{/isNullable}}
 }
 }

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

@@ -129,7 +129,6 @@ public class AbstractJavaCodegenTest {
         Assert.assertEquals(codegen.getInvokerPackage(), "org.openapitools");
         Assert.assertEquals(codegen.additionalProperties().get(CodegenConstants.INVOKER_PACKAGE), "org.openapitools");
         Assert.assertEquals(codegen.additionalProperties().get(AbstractJavaCodegen.BOOLEAN_GETTER_PREFIX), "get");
-        Assert.assertEquals(codegen.additionalProperties().get(AbstractJavaCodegen.USE_NULL_FOR_UNKNOWN_ENUM_VALUE), Boolean.FALSE);
     }
 
     @Test
@@ -140,7 +139,6 @@ public class AbstractJavaCodegenTest {
         codegen.setApiPackage("xyz.yyyyy.zzzzzzz.api");
         codegen.setInvokerPackage("xyz.yyyyy.zzzzzzz.invoker");
         codegen.setBooleanGetterPrefix("is");
-        codegen.setUseNullForUnknownEnumValue(true);
         codegen.processOpts();
 
         Assert.assertEquals(codegen.additionalProperties().get(CodegenConstants.HIDE_GENERATION_TIMESTAMP), Boolean.TRUE);
@@ -152,7 +150,6 @@ public class AbstractJavaCodegenTest {
         Assert.assertEquals(codegen.getInvokerPackage(), "xyz.yyyyy.zzzzzzz.invoker");
         Assert.assertEquals(codegen.additionalProperties().get(CodegenConstants.INVOKER_PACKAGE), "xyz.yyyyy.zzzzzzz.invoker");
         Assert.assertEquals(codegen.additionalProperties().get(AbstractJavaCodegen.BOOLEAN_GETTER_PREFIX), "is");
-        Assert.assertEquals(codegen.additionalProperties().get(AbstractJavaCodegen.USE_NULL_FOR_UNKNOWN_ENUM_VALUE), Boolean.TRUE);
     }
 
     @Test
@@ -163,7 +160,6 @@ public class AbstractJavaCodegenTest {
         codegen.additionalProperties().put(CodegenConstants.API_PACKAGE, "xyz.yyyyy.api.oooooo");
         codegen.additionalProperties().put(CodegenConstants.INVOKER_PACKAGE, "xyz.yyyyy.invoker.oooooo");
         codegen.additionalProperties().put(AbstractJavaCodegen.BOOLEAN_GETTER_PREFIX, "getBoolean");
-        codegen.additionalProperties().put(AbstractJavaCodegen.USE_NULL_FOR_UNKNOWN_ENUM_VALUE, "true");
         codegen.processOpts();
 
         Assert.assertEquals(codegen.additionalProperties().get(CodegenConstants.HIDE_GENERATION_TIMESTAMP), Boolean.FALSE);
@@ -175,7 +171,6 @@ public class AbstractJavaCodegenTest {
         Assert.assertEquals(codegen.getInvokerPackage(), "xyz.yyyyy.invoker.oooooo");
         Assert.assertEquals(codegen.additionalProperties().get(CodegenConstants.INVOKER_PACKAGE), "xyz.yyyyy.invoker.oooooo");
         Assert.assertEquals(codegen.additionalProperties().get(AbstractJavaCodegen.BOOLEAN_GETTER_PREFIX), "getBoolean");
-        Assert.assertEquals(codegen.additionalProperties().get(AbstractJavaCodegen.USE_NULL_FOR_UNKNOWN_ENUM_VALUE), Boolean.TRUE);
     }
 
     @Test

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

@@ -133,11 +133,6 @@ public class JavaJAXRSCXFExtServerCodegenTest extends JavaJaxrsBaseTest {
             return useMultipartFeature;
         }
 
-        // AbstractJavaCodegen.USE_NULL_FOR_UNKNOWN_ENUM_VALUE
-        public boolean isUseNullForUnknownEnumValue() {
-            return useNullForUnknownEnumValue;
-        }
-
         // SpringFeatures.USE_SPRING_ANNOTATION_CONFIG
         public boolean isUseSpringAnnotationConfig() {
             return useSpringAnnotationConfig;
@@ -253,7 +248,6 @@ public class JavaJAXRSCXFExtServerCodegenTest extends JavaJaxrsBaseTest {
         additionalProperties.put(AbstractJavaCodegen.JAVA8_MODE, "true");
         additionalProperties.put(AbstractJavaCodegen.SUPPORT_ASYNC, "true");
         additionalProperties.put(AbstractJavaCodegen.SUPPORT_JAVA6, "false");
-        additionalProperties.put(AbstractJavaCodegen.USE_NULL_FOR_UNKNOWN_ENUM_VALUE, "true");
         additionalProperties.put(AbstractJavaCodegen.WITH_XML, "true");
         // Options processed by AbstractJavaJAXRSServerCodegen
         additionalProperties.put(CodegenConstants.IMPL_FOLDER, "myimpl");
@@ -328,7 +322,6 @@ public class JavaJAXRSCXFExtServerCodegenTest extends JavaJaxrsBaseTest {
         assertEquals(testerCodegen.isFullJavaUtil(), true);
         assertEquals(testerCodegen.isJava8Mode(), true);
         assertEquals(testerCodegen.isSupportAsync(), true);
-        assertEquals(testerCodegen.isUseNullForUnknownEnumValue(), true);
         assertEquals(testerCodegen.isWithXml(), true);
         // Options processed by AbstractJavaJAXRSServerCodegen
         assertEquals(testerCodegen.getImplFolder(), "myimpl");
@@ -581,7 +574,6 @@ public class JavaJAXRSCXFExtServerCodegenTest extends JavaJaxrsBaseTest {
         assertNull(additionalProperties.get(AbstractJavaCodegen.JAVA8_MODE));
         assertNull(additionalProperties.get(AbstractJavaCodegen.SUPPORT_ASYNC));
         assertEquals(additionalProperties.get(AbstractJavaCodegen.SUPPORT_JAVA6), Boolean.FALSE);
-        assertEquals(additionalProperties.get(AbstractJavaCodegen.USE_NULL_FOR_UNKNOWN_ENUM_VALUE), false);
         assertEquals(additionalProperties.get(AbstractJavaCodegen.WITH_XML), false);
         // Options processed by AbstractJavaJAXRSServerCodegen
         assertNull(additionalProperties.get(CodegenConstants.IMPL_FOLDER));

modules/openapi-generator/src/test/resources/3_0/petstore-with-fake-endpoints-models-for-testing.yaml

@@ -1580,6 +1580,7 @@ components:
               - fish
               - crab
     OuterEnum:
+      nullable: true
       type: string
       enum:
         - placed

samples/client/petstore/java/jersey1/src/main/java/org/openapitools/client/model/EnumArrays.java

@@ -59,7 +59,7 @@ public class EnumArrays {
           return b;
         }
       }
-      return null;
+      throw new IllegalArgumentException("Unexpected value '" + value + "'");
     }
   }
 
@@ -97,7 +97,7 @@ public class EnumArrays {
           return b;
         }
       }
-      return null;
+      throw new IllegalArgumentException("Unexpected value '" + value + "'");
     }
   }
 

samples/client/petstore/java/jersey1/src/main/java/org/openapitools/client/model/EnumClass.java

@@ -53,7 +53,7 @@ public enum EnumClass {
         return b;
       }
     }
-    return null;
+    throw new IllegalArgumentException("Unexpected value '" + value + "'");
   }
 }
 

samples/client/petstore/java/jersey1/src/main/java/org/openapitools/client/model/EnumTest.java

@@ -60,7 +60,7 @@ public class EnumTest {
           return b;
         }
       }
-      return null;
+      throw new IllegalArgumentException("Unexpected value '" + value + "'");
     }
   }
 
@@ -100,7 +100,7 @@ public class EnumTest {
           return b;
         }
       }
-      return null;
+      throw new IllegalArgumentException("Unexpected value '" + value + "'");
     }
   }
 
@@ -138,7 +138,7 @@ public class EnumTest {
           return b;
         }
       }
-      return null;
+      throw new IllegalArgumentException("Unexpected value '" + value + "'");
     }
   }
 
@@ -176,7 +176,7 @@ public class EnumTest {
           return b;
         }
       }
-      return null;
+      throw new IllegalArgumentException("Unexpected value '" + value + "'");
     }
   }
 

samples/client/petstore/java/jersey1/src/main/java/org/openapitools/client/model/MapTest.java

@@ -63,7 +63,7 @@ public class MapTest {
           return b;
         }
       }
-      return null;
+      throw new IllegalArgumentException("Unexpected value '" + value + "'");
     }
   }
 

samples/client/petstore/java/jersey1/src/main/java/org/openapitools/client/model/Order.java

@@ -72,7 +72,7 @@ public class Order {
           return b;
         }
       }
-      return null;
+      throw new IllegalArgumentException("Unexpected value '" + value + "'");
     }
   }
 

samples/client/petstore/java/jersey1/src/main/java/org/openapitools/client/model/OuterEnum.java

@@ -53,7 +53,7 @@ public enum OuterEnum {
         return b;
       }
     }
-    return null;
+    throw new IllegalArgumentException("Unexpected value '" + value + "'");
   }
 }
 

samples/client/petstore/java/jersey1/src/main/java/org/openapitools/client/model/Pet.java

@@ -78,7 +78,7 @@ public class Pet {
           return b;
         }
       }
-      return null;
+      throw new IllegalArgumentException("Unexpected value '" + value + "'");
     }
   }
 

samples/openapi3/client/petstore/python/petstore_api/models/enum_test.py

@@ -72,7 +72,6 @@ class EnumTest(object):
             self.enum_integer = enum_integer
         if enum_number is not None:
             self.enum_number = enum_number
-        if outer_enum is not None:
         self.outer_enum = outer_enum
         if outer_enum_integer is not None:
             self.outer_enum_integer = outer_enum_integer

samples/server/petstore/jaxrs-jersey/src/gen/java/org/openapitools/model/OuterEnum.java

@@ -55,7 +55,7 @@ public enum OuterEnum {
         return b;
       }
     }
-    throw new IllegalArgumentException("Unexpected value '" + value + "'");
+    return null;
   }
 }