[Java] Feature/wrapped types and default values

bin/configs/spring-boot-oas3-nullable-disabled.yaml

@@ -0,0 +1,14 @@
+generatorName: spring
+outputDir: samples/openapi3/server/petstore/springboot-nullable-disabled
+inputSpec: modules/openapi-generator/src/test/resources/3_0/petstore-with-nullable-required.yaml
+templateDir: modules/openapi-generator/src/main/resources/JavaSpring
+additionalProperties:
+  groupId: org.openapitools.openapi3
+  documentationProvider: springdoc
+  artifactId: springboot-nullable-disabled
+  snapshotVersion: "true"
+  hideGenerationTimestamp: "true"
+  openApiNullable: "false"
+  useOptional: "true"
+  useOptionalInModel: "true"
+  exposeOptionalInSetter: "true"

bin/configs/spring-boot-oas3-nullable.yaml

@@ -0,0 +1,14 @@
+generatorName: spring
+outputDir: samples/openapi3/server/petstore/springboot-nullable
+inputSpec: modules/openapi-generator/src/test/resources/3_0/petstore-with-nullable-required.yaml
+templateDir: modules/openapi-generator/src/main/resources/JavaSpring
+additionalProperties:
+  groupId: org.openapitools.openapi3
+  documentationProvider: springdoc
+  artifactId: springboot-nullable
+  snapshotVersion: "true"
+  hideGenerationTimestamp: "true"
+  openApiNullable: "true"
+  useOptional: "true"
+  useOptionalInModel: "true"
+  exposeOptionalInSetter: "true"

bin/configs/spring-boot-oas3.yaml

@@ -1,10 +1,12 @@
 generatorName: spring
 outputDir: samples/openapi3/server/petstore/springboot
-inputSpec: modules/openapi-generator/src/test/resources/3_0/petstore.yaml
+inputSpec: modules/openapi-generator/src/test/resources/3_0/petstore-nullable.yaml
 templateDir: modules/openapi-generator/src/main/resources/JavaSpring
 additionalProperties:
   groupId: org.openapitools.openapi3
   documentationProvider: springdoc
+  useOptional: true
+  useOptionalInModel: "true"
   artifactId: springboot
   snapshotVersion: "true"
   hideGenerationTimestamp: "true"

docs/generators/java-camel.md

@@ -52,6 +52,7 @@ These options may be applied as additional-properties (cli) or configOptions (pl
 |documentationProvider|Select the OpenAPI documentation provider.|<dl><dt>**none**</dt><dd>Do not publish an OpenAPI specification.</dd><dt>**source**</dt><dd>Publish the original input OpenAPI specification.</dd><dt>**springfox**</dt><dd>Generate an OpenAPI 2 (fka Swagger RESTful API Documentation Specification) specification using SpringFox 2.x. Deprecated (for removal); use springdoc instead.</dd><dt>**springdoc**</dt><dd>Generate an OpenAPI 3 specification using SpringDoc.</dd></dl>|springdoc|
 |ensureUniqueParams|Whether to ensure parameter names are unique in an operation (rename parameters that are not).| |true|
 |enumUnknownDefaultCase|If the server adds new enum cases, that are unknown by an old spec/client, the client will fail to parse the network response.With this option enabled, each enum will have a new case, 'unknown_default_open_api', so that when the server sends an enum case that is not known by the client/spec, they can safely fallback to this case.|<dl><dt>**false**</dt><dd>No changes to the enum's are made, this is the default option.</dd><dt>**true**</dt><dd>With this option enabled, each enum will have a new case, 'unknown_default_open_api', so that when the enum case sent by the server is not known by the client/spec, can safely be decoded to this case.</dd></dl>|false|
+|exposeOptionalInSetter|Experimental: When using Optional container for optional model properties, expose Optional container in generated setter method| |false|
 |fullJavaUtil|whether to use fully qualified name for classes under java.util. This option only works for Java API client| |false|
 |groupId|groupId in generated pom.xml| |org.openapitools|
 |hateoas|Use Spring HATEOAS library to allow adding HATEOAS links| |false|
@@ -89,6 +90,7 @@ These options may be applied as additional-properties (cli) or configOptions (pl
 |unhandledException|Declare operation methods to throw a generic exception and allow unhandled exceptions (useful for Spring `@ControllerAdvice` directives).| |false|
 |useBeanValidation|Use BeanValidation API annotations| |true|
 |useOptional|Use Optional container for optional parameters| |false|
+|useOptionalInModel|Experimental: Use Optional container for optional model properties| |false|
 |useSpringController|Annotate the generated API as a Spring Controller| |false|
 |useSwaggerUI|Open the OpenApi specification in swagger-ui. Will also import and configure needed dependencies| |true|
 |useTags|use tags for creating interface and controller classnames| |false|

docs/generators/spring.md

@@ -45,6 +45,7 @@ These options may be applied as additional-properties (cli) or configOptions (pl
 |documentationProvider|Select the OpenAPI documentation provider.|<dl><dt>**none**</dt><dd>Do not publish an OpenAPI specification.</dd><dt>**source**</dt><dd>Publish the original input OpenAPI specification.</dd><dt>**springfox**</dt><dd>Generate an OpenAPI 2 (fka Swagger RESTful API Documentation Specification) specification using SpringFox 2.x. Deprecated (for removal); use springdoc instead.</dd><dt>**springdoc**</dt><dd>Generate an OpenAPI 3 specification using SpringDoc.</dd></dl>|springdoc|
 |ensureUniqueParams|Whether to ensure parameter names are unique in an operation (rename parameters that are not).| |true|
 |enumUnknownDefaultCase|If the server adds new enum cases, that are unknown by an old spec/client, the client will fail to parse the network response.With this option enabled, each enum will have a new case, 'unknown_default_open_api', so that when the server sends an enum case that is not known by the client/spec, they can safely fallback to this case.|<dl><dt>**false**</dt><dd>No changes to the enum's are made, this is the default option.</dd><dt>**true**</dt><dd>With this option enabled, each enum will have a new case, 'unknown_default_open_api', so that when the enum case sent by the server is not known by the client/spec, can safely be decoded to this case.</dd></dl>|false|
+|exposeOptionalInSetter|Experimental: When using Optional container for optional model properties, expose Optional container in generated setter method| |false|
 |fullJavaUtil|whether to use fully qualified name for classes under java.util. This option only works for Java API client| |false|
 |groupId|groupId in generated pom.xml| |org.openapitools|
 |hateoas|Use Spring HATEOAS library to allow adding HATEOAS links| |false|
@@ -82,6 +83,7 @@ These options may be applied as additional-properties (cli) or configOptions (pl
 |unhandledException|Declare operation methods to throw a generic exception and allow unhandled exceptions (useful for Spring `@ControllerAdvice` directives).| |false|
 |useBeanValidation|Use BeanValidation API annotations| |true|
 |useOptional|Use Optional container for optional parameters| |false|
+|useOptionalInModel|Experimental: Use Optional container for optional model properties| |false|
 |useSpringController|Annotate the generated API as a Spring Controller| |false|
 |useSwaggerUI|Open the OpenApi specification in swagger-ui. Will also import and configure needed dependencies| |true|
 |useTags|use tags for creating interface and controller classnames| |false|

modules/openapi-generator-maven-plugin/examples/camel.xml

@@ -192,7 +192,7 @@
 	<properties>
 		<swagger-annotations-version>1.5.8</swagger-annotations-version>
 
-		<spring-boot-starter-web.version>2.2.1.RELEASE</spring-boot-starter-web.version>
+		<spring-boot-starter-web.version>2.6.3</spring-boot-starter-web.version>
 		<springfox-version>2.8.0</springfox-version>
 	</properties>
 </project>

modules/openapi-generator-maven-plugin/examples/spring.xml

@@ -11,7 +11,7 @@
 	<parent>
 		<groupId>org.springframework.boot</groupId>
 		<artifactId>spring-boot-starter-parent</artifactId>
-		<version>2.2.1.RELEASE</version>
+		<version>2.6.3</version>
 	</parent>
 	<build>
 		<plugins>
@@ -126,7 +126,7 @@
 	<properties>
 		<swagger-annotations-version>1.5.8</swagger-annotations-version>
 
-		<spring-boot-starter-web.version>2.2.1.RELEASE</spring-boot-starter-web.version>
+		<spring-boot-starter-web.version>2.6.3</spring-boot-starter-web.version>
 		<springfox-version>2.8.0</springfox-version>
 	</properties>
 </project>

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

@@ -40,6 +40,31 @@ public class CodegenProperty implements Cloneable, IJsonSchemaValidationProperti
     public String dataType;
     public String datatypeWithEnum;
     public String dataFormat;
+
+    /**
+     * Detect support for Wrapper Types.
+     * When isWrapped is true, the dataType should be wrapped using wrapperType.
+     */
+    public boolean isWrapped;
+    /**
+     * The Wrapper Type itself. Wrapper Types are for Example {@link Optional} or
+     * org.openapitools.jackson.nullable.JsonNullable.
+     */
+    public String wrapperType;
+    /**
+     * The concrete Wrapped Type declaration, ie {@code JsonNullable<String>} or {@code Optional<String>}.
+     */
+    public String wrappedType;
+    /**
+     * A Function to wrap a dataType.
+     * For example JsonNullable.of or Optional.ofNullable.
+     */
+    public String wrapperFunc;
+    /**
+     * The wrapped defaultValue.
+     */
+    public String wrappedDefault;
+
     /**
      * The name of this property in the OpenAPI schema.
      */
@@ -955,6 +980,11 @@ public String toString() {
         sb.append(", getHasDiscriminatorWithNonEmptyMapping=").append(hasDiscriminatorWithNonEmptyMapping);
         sb.append(", composedSchemas=").append(composedSchemas);
         sb.append(", hasMultipleTypes=").append(hasMultipleTypes);
+        sb.append(", isWrapped=").append(isWrapped);
+        sb.append(", wrapperType=").append(wrapperType);
+        sb.append(", wrappedType=").append(wrappedType);
+        sb.append(", wrapperFunc=").append(wrapperFunc);
+        sb.append(", wrappedDefault=").append(wrappedDefault);
         sb.append('}');
         return sb.toString();
     }
@@ -1054,7 +1084,12 @@ public boolean equals(Object o) {
                 Objects.equals(xmlPrefix, that.xmlPrefix) &&
                 Objects.equals(xmlName, that.xmlName) &&
                 Objects.equals(xmlNamespace, that.xmlNamespace) &&
-                Objects.equals(multipleOf, that.multipleOf);
+                Objects.equals(multipleOf, that.multipleOf) &&
+                isWrapped == that.isWrapped &&
+                Objects.equals(wrapperType, that.wrapperType) &&
+                Objects.equals(wrappedType, that.wrappedType) &&
+                Objects.equals(wrapperFunc, that.wrapperFunc) &&
+                Objects.equals(wrappedDefault, that.wrappedDefault);
     }
 
     @Override
@@ -1074,6 +1109,7 @@ public int hashCode() {
                 vendorExtensions, hasValidation, isInherited, discriminatorValue, nameInCamelCase,
                 nameInSnakeCase, enumName, maxItems, minItems, isXmlAttribute, xmlPrefix, xmlName,
                 xmlNamespace, isXmlWrapped, isNull, additionalPropertiesIsAnyType, hasVars, hasRequired,
-                hasDiscriminatorWithNonEmptyMapping, composedSchemas, hasMultipleTypes);
+                hasDiscriminatorWithNonEmptyMapping, composedSchemas, hasMultipleTypes, isWrapped, wrapperType,
+                wrappedType, wrapperFunc, wrappedDefault);
     }
 }

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

@@ -17,40 +17,72 @@
 
 package org.openapitools.codegen.languages;
 
+import static org.openapitools.codegen.utils.StringUtils.camelize;
+import static org.openapitools.codegen.utils.StringUtils.escape;
+import static org.openapitools.codegen.utils.StringUtils.underscore;
+
 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;
 import io.swagger.v3.oas.models.examples.Example;
-import io.swagger.v3.oas.models.media.*;
+import io.swagger.v3.oas.models.media.ArraySchema;
+import io.swagger.v3.oas.models.media.ComposedSchema;
+import io.swagger.v3.oas.models.media.Content;
+import io.swagger.v3.oas.models.media.MediaType;
+import io.swagger.v3.oas.models.media.Schema;
+import io.swagger.v3.oas.models.media.StringSchema;
 import io.swagger.v3.oas.models.parameters.Parameter;
 import io.swagger.v3.oas.models.parameters.RequestBody;
 import io.swagger.v3.oas.models.servers.Server;
 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.*;
-import org.openapitools.codegen.languages.features.DocumentationProviderFeatures;
-import org.openapitools.codegen.meta.features.*;
-import org.openapitools.codegen.utils.ModelUtils;
-import org.slf4j.Logger;
-import org.slf4j.LoggerFactory;
-
 import java.io.File;
 import java.io.IOException;
 import java.time.LocalDate;
 import java.time.ZoneId;
-import java.util.*;
+import java.util.ArrayList;
+import java.util.Arrays;
+import java.util.Collection;
+import java.util.Date;
+import java.util.EnumSet;
+import java.util.HashMap;
+import java.util.Iterator;
+import java.util.LinkedList;
+import java.util.List;
+import java.util.ListIterator;
+import java.util.Locale;
+import java.util.Map;
+import java.util.Objects;
+import java.util.Set;
 import java.util.concurrent.ConcurrentSkipListSet;
 import java.util.regex.Pattern;
 import java.util.stream.Stream;
-
-import static org.openapitools.codegen.utils.StringUtils.*;
+import org.apache.commons.io.FilenameUtils;
+import org.apache.commons.lang3.BooleanUtils;
+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.CodegenModel;
+import org.openapitools.codegen.CodegenOperation;
+import org.openapitools.codegen.CodegenParameter;
+import org.openapitools.codegen.CodegenProperty;
+import org.openapitools.codegen.DefaultCodegen;
+import org.openapitools.codegen.languages.features.DocumentationProviderFeatures;
+import org.openapitools.codegen.languages.features.OptionalFeatures;
+import org.openapitools.codegen.meta.features.ClientModificationFeature;
+import org.openapitools.codegen.meta.features.DocumentationFeature;
+import org.openapitools.codegen.meta.features.GlobalFeature;
+import org.openapitools.codegen.meta.features.SchemaSupportFeature;
+import org.openapitools.codegen.meta.features.SecurityFeature;
+import org.openapitools.codegen.meta.features.WireFormatFeature;
+import org.openapitools.codegen.utils.ModelUtils;
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
 
 public abstract class AbstractJavaCodegen extends DefaultCodegen implements CodegenConfig,
-        DocumentationProviderFeatures {
+        DocumentationProviderFeatures, OptionalFeatures {
 
     private final Logger LOGGER = LoggerFactory.getLogger(AbstractJavaCodegen.class);
     private static final String ARTIFACT_VERSION_DEFAULT_VALUE = "1.0.0";
@@ -117,6 +149,9 @@ public abstract class AbstractJavaCodegen extends DefaultCodegen implements Code
     protected String outputTestFolder = "";
     protected DocumentationProvider documentationProvider;
     protected AnnotationLibrary annotationLibrary;
+    protected boolean useOptional = false;
+    protected boolean useOptionalInModel = false;
+    protected boolean exposeOptionalInSetter = false;
 
     public AbstractJavaCodegen() {
         super();
@@ -585,6 +620,7 @@ public void processOpts() {
         importMapping.put("IOException", "java.io.IOException");
         importMapping.put("Arrays", "java.util.Arrays");
         importMapping.put("Objects", "java.util.Objects");
+        importMapping.put("Optional", "java.util.Optional");
         importMapping.put("StringUtil", invokerPackage + ".StringUtil");
         // import JsonCreator if JsonProperty is imported
         // used later in recursive import in postProcessingModels
@@ -1286,9 +1322,43 @@ public void postProcessModelProperty(CodegenModel model, CodegenProperty propert
         }
 
         if (openApiNullable) {
+            // see org.openapitools.codegen.java.JavaCXFClientCodegenTest.testPostProcessNullableModelPropertyWithOpenApiNullableEnabledForRequiredProperties
             if (Boolean.FALSE.equals(property.required) && Boolean.TRUE.equals(property.isNullable)) {
+                // Only add import when needed
                 model.imports.add("JsonNullable");
                 model.getVendorExtensions().put("x-jackson-optional-nullable-helpers", true);
+                property.getVendorExtensions().put("x-expose-wrapper-in-setter", true);
+                // Wrap dataType and defaults
+                property.isWrapped = true;
+                property.wrapperType = "JsonNullable";
+                property.wrappedType = "JsonNullable<" + property.datatypeWithEnum + ">";
+                property.wrapperFunc = "JsonNullable.of";
+                property.wrappedDefault = "JsonNullable.undefined()";
+                if (!property.isContainer && property.defaultValue != null) {
+                    property.wrappedDefault = "JsonNullable.of(" + property.defaultValue + ")";
+                }
+            }
+        }
+        if (useOptionalInModel) {
+            if (Boolean.FALSE.equals(property.required) && Boolean.FALSE.equals(property.isNullable)
+                && !property.isArray && !property.isMap) {
+                // Only add import when needed
+                model.imports.add("Optional");
+                if (exposeOptionalInSetter) {
+                    property.getVendorExtensions().put("x-expose-wrapper-in-setter", true);
+                } else {
+                    model.imports.add("JsonIgnore");
+                }
+                // Wrap dataType and defaults
+                property.isWrapped = true;
+                property.wrapperType = "Optional";
+                property.wrappedType = "Optional<" + property.datatypeWithEnum + ">";
+                property.wrapperFunc = "Optional.ofNullable";
+                if (property.defaultValue != null) {
+                    property.wrappedDefault = "Optional.of(" + property.defaultValue + ")";
+                } else {
+                    property.wrappedDefault = "Optional.empty()";
+                }
             }
         }
 
@@ -1808,6 +1878,21 @@ public void setAnnotationLibrary(AnnotationLibrary annotationLibrary) {
         this.annotationLibrary = annotationLibrary;
     }
 
+    @Override
+    public void setUseOptional(boolean useOptional) {
+        this.useOptional = useOptional;
+    }
+
+    @Override
+    public void setUseOptionalInModel(boolean useOptionalInModel) {
+        this.useOptionalInModel = useOptionalInModel;
+    }
+
+    @Override
+    public void setExposeOptionalInSetter(boolean exposeOptionalInSetter) {
+        this.exposeOptionalInSetter = exposeOptionalInSetter;
+    }
+
     @Override
     public String escapeQuotationMark(String input) {
         // remove " to avoid code injection