Add setting for generating the oneOf interfaces as sealed interfaces

Author: Mattias-Sehlstedt

.github/workflows/samples-java-client-jdk17.yaml

@@ -6,13 +6,15 @@ on:
       - samples/client/petstore/java/resttemplate-jakarta/**
       - samples/client/petstore/java/webclient-jakarta/**
       - samples/client/petstore/java/restclient-*/**
+      - samples/client/petstore/java/webclient-sealedInterface/**
       - samples/client/petstore/java/webclient-useSingleRequestParameter/**
       - samples/client/others/java/restclient-enum-in-multipart/**
   pull_request:
     paths:
       - samples/client/petstore/java/resttemplate-jakarta/**
       - samples/client/petstore/java/webclient-jakarta/**
       - samples/client/petstore/java/restclient-*/**
+      - samples/client/petstore/java/webclient-sealedInterface/**
       - samples/client/petstore/java/webclient-useSingleRequestParameter/**
       - samples/client/others/java/restclient-enum-in-multipart/**
 jobs:
@@ -31,6 +33,7 @@ jobs:
           - samples/client/petstore/java/restclient-swagger2
           - samples/client/petstore/java/restclient-useSingleRequestParameter
           - samples/client/petstore/java/restclient-useSingleRequestParameter-static
+          - samples/client/petstore/java/webclient-sealedInterface
           - samples/client/petstore/java/webclient-useSingleRequestParameter
           - samples/client/others/java/restclient-enum-in-multipart
     steps:

bin/configs/java-webclient-sealedInterface.yaml

@@ -0,0 +1,10 @@
+generatorName: java
+outputDir: samples/client/petstore/java/webclient-sealedInterface
+library: webclient
+inputSpec: modules/openapi-generator/src/test/resources/3_0/petstore-with-fake-endpoints-models-for-testing.yaml
+templateDir: modules/openapi-generator/src/main/resources/Java
+additionalProperties:
+  artifactId: sealed-interface-webclient
+  hideGenerationTimestamp: "true"
+  useOneOfInterfaces: true
+  useSealedOneOfInterfaces: true

docs/generators/java.md

@@ -98,6 +98,7 @@ These options may be applied as additional-properties (cli) or configOptions (pl
 |useJakartaEe|whether to use Jakarta EE namespace instead of javax| |false|
 |useOneOfDiscriminatorLookup|Use the discriminator's mapping in oneOf to speed up the model lookup. IMPORTANT: Validation (e.g. one and only one match in oneOf's schemas) will be skipped. Only jersey2, jersey3, native, okhttp-gson support this option.| |false|
 |useOneOfInterfaces|whether to use a java interface to describe a set of oneOf options, where each option is a class that implements the interface| |false|
+|useSealedOneOfInterfaces|Generate the oneOf interfaces as sealed interfaces. Only supported for WebClient and RestClient.| |false|
 |usePlayWS|Use Play! Async HTTP client (Play WS API)| |false|
 |useReflectionEqualsHashCode|Use org.apache.commons.lang3.builder for equals and hashCode in the models. WARNING: This will fail under a security manager, unless the appropriate permissions are set up correctly and also there's potential performance impact.| |false|
 |useRuntimeException|Use RuntimeException instead of Exception. Only jersey2, jersey3, okhttp-gson, vertx, microprofile support this option.| |false|

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

@@ -104,6 +104,13 @@ public class JavaClientCodegen extends AbstractJavaCodegen
     public static final String USE_ENUM_CASE_INSENSITIVE = "useEnumCaseInsensitive";
     public static final String FAIL_ON_UNKNOWN_PROPERTIES = "failOnUnknownProperties";
     public static final String SUPPORT_VERTX_FUTURE = "supportVertxFuture";
+    public static final String USE_SEALED_ONE_OF_INTERFACES = "useSealedOneOfInterfaces";
+
+    // Internal configurations
+    public static final String SINGLE_REQUEST_PARAMETER = "singleRequestParameter";
+    public static final String STATIC_REQUEST = "staticRequest";
+    // TODO attempt to implement the setting similar to how it is done here https://github.com/OpenAPITools/openapi-generator/pull/20590/files
+    public static final String JAVA_17 = "java17";
 
     public static final String SERIALIZATION_LIBRARY_GSON = "gson";
     public static final String SERIALIZATION_LIBRARY_JACKSON = "jackson";
@@ -142,6 +149,7 @@ public class JavaClientCodegen extends AbstractJavaCodegen
     @Setter protected String errorObjectType;
     @Getter @Setter protected boolean failOnUnknownProperties = false;
     @Setter protected boolean supportVertxFuture = false;
+    @Setter protected boolean useSealedOneOfInterfaces = false;
     protected String authFolder;
     /**
      * Serialization library.
@@ -252,6 +260,7 @@ public JavaClientCodegen() {
         cliOptions.add(CliOption.newBoolean(USE_ENUM_CASE_INSENSITIVE, "Use `equalsIgnoreCase` when String for enum comparison", useEnumCaseInsensitive));
         cliOptions.add(CliOption.newBoolean(FAIL_ON_UNKNOWN_PROPERTIES, "Fail Jackson de-serialization on unknown properties", this.failOnUnknownProperties));
         cliOptions.add(CliOption.newBoolean(SUPPORT_VERTX_FUTURE, "Also generate api methods that return a vertx Future instead of taking a callback. Only `vertx` supports this option. Requires vertx 4 or greater.", this.supportVertxFuture));
+        cliOptions.add(CliOption.newBoolean(USE_SEALED_ONE_OF_INTERFACES, "Generate the oneOf interfaces as sealed interfaces", this.useSealedOneOfInterfaces));
 
         supportedLibraries.put(JERSEY2, "HTTP client: Jersey client 2.25.1. JSON processing: Jackson 2.17.1");
         supportedLibraries.put(JERSEY3, "HTTP client: Jersey client 3.1.1. JSON processing: Jackson 2.17.1");
@@ -367,8 +376,9 @@ public void processOpts() {
             convertPropertyToBooleanAndWriteBack(USE_RX_JAVA2, this::setUseRxJava2);
         }
         convertPropertyToStringAndWriteBack(CodegenConstants.USE_SINGLE_REQUEST_PARAMETER, this::setUseSingleRequestParameter);
-        writePropertyBack("singleRequestParameter", getSingleRequestParameter());
-        writePropertyBack("staticRequest", getStaticRequest());
+        convertPropertyToBooleanAndWriteBack(USE_SEALED_ONE_OF_INTERFACES, this::setUseSealedOneOfInterfaces);
+        writePropertyBack(SINGLE_REQUEST_PARAMETER, getSingleRequestParameter());
+        writePropertyBack(STATIC_REQUEST, getStaticRequest());
 
         if (!useRxJava && !useRxJava2 && !useRxJava3) {
             additionalProperties.put(DO_NOT_USE_RX, true);

modules/openapi-generator/src/main/resources/Java/libraries/restclient/pojo.mustache

@@ -29,7 +29,7 @@
 {{#vendorExtensions.x-class-extra-annotation}}
 {{{vendorExtensions.x-class-extra-annotation}}}
 {{/vendorExtensions.x-class-extra-annotation}}
-public class {{classname}} {{#parent}}extends {{{.}}} {{/parent}}{{#vendorExtensions.x-implements}}{{#-first}}implements {{{.}}}{{/-first}}{{^-first}}, {{{.}}}{{/-first}}{{#-last}} {{/-last}}{{/vendorExtensions.x-implements}}{
+public {{>sealed}}class {{classname}} {{#parent}}extends {{{.}}} {{/parent}}{{#vendorExtensions.x-implements}}{{#-first}}implements {{{.}}}{{/-first}}{{^-first}}, {{{.}}}{{/-first}}{{#-last}} {{/-last}}{{/vendorExtensions.x-implements}}{{>permits}}{
 {{#serializableModel}}
   private static final long serialVersionUID = 1L;
 

modules/openapi-generator/src/main/resources/Java/libraries/webclient/pojo.mustache

@@ -29,7 +29,7 @@
 {{#vendorExtensions.x-class-extra-annotation}}
 {{{vendorExtensions.x-class-extra-annotation}}}
 {{/vendorExtensions.x-class-extra-annotation}}
-public class {{classname}} {{#parent}}extends {{{.}}} {{/parent}}{{#vendorExtensions.x-implements}}{{#-first}}implements {{{.}}}{{/-first}}{{^-first}}, {{{.}}}{{/-first}}{{#-last}} {{/-last}}{{/vendorExtensions.x-implements}}{
+public {{>sealed}}class {{classname}} {{#parent}}extends {{{.}}} {{/parent}}{{#vendorExtensions.x-implements}}{{#-first}}implements {{{.}}}{{/-first}}{{^-first}}, {{{.}}}{{/-first}}{{#-last}} {{/-last}}{{/vendorExtensions.x-implements}}{{>permits}}{
 {{#serializableModel}}
   private static final long serialVersionUID = 1L;
 

modules/openapi-generator/src/main/resources/Java/libraries/webclient/pom.mustache

@@ -45,14 +45,14 @@
                 <artifactId>maven-compiler-plugin</artifactId>
                 <version>3.13.0</version>
                 <configuration>
-                {{#useJakartaEe}}
+                {{#java17}}
                     <source>17</source>
                     <target>17</target>
-                {{/useJakartaEe}}
-                {{^useJakartaEe}}
+                {{/java17}}
+                {{^java17}}
                     <source>1.8</source>
                     <target>1.8</target>
-                {{/useJakartaEe}}
+                {{/java17}}
                 </configuration>
             </plugin>
             <plugin>

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

@@ -1,5 +1,5 @@
 {{>additionalOneOfTypeAnnotations}}{{>generatedAnnotation}}{{>typeInfoAnnotation}}{{>xmlAnnotation}}
-public interface {{classname}} {{#vendorExtensions.x-implements}}{{#-first}}extends {{{.}}}{{/-first}}{{^-first}}, {{{.}}}{{/-first}}{{/vendorExtensions.x-implements}} {
+public {{>sealed}}interface {{classname}} {{#vendorExtensions.x-implements}}{{#-first}}extends {{{.}}}{{/-first}}{{^-first}}, {{{.}}}{{/-first}}{{/vendorExtensions.x-implements}}{{>permits}}{
     {{#discriminator}}
     public {{propertyType}} {{propertyGetter}}();
     {{/discriminator}}

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

@@ -0,0 +1 @@
+{{#useSealedOneOfInterfaces}}{{#vendorExtensions.x-is-one-of-interface}}{{#permits}}{{#-first}}permits {{/-first}}{{{.}}}{{^-last}}, {{/-last}}{{#-last}} {{/-last}}{{/permits}}{{/vendorExtensions.x-is-one-of-interface}}{{/useSealedOneOfInterfaces}}

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

@@ -0,0 +1 @@
+{{#useSealedOneOfInterfaces}}{{#permits.0}}sealed {{/permits.0}}{{^permits.0}}{{^vendorExtensions.x-is-one-of-interface}}{{#vendorExtensions.x-implements}}final {{/vendorExtensions.x-implements}}{{/vendorExtensions.x-is-one-of-interface}}{{/permits.0}}{{/useSealedOneOfInterfaces}}