[JAVA] [WebClient] Handle list of String special case in WebClient generator (#16326)

* [Java][WebClient] support string list return type

* [Java][WebClient] add test

* [Java][WebClient] support string list return type

* [Java][WebClient] support string list return type

* fix webclient auto-generated test files

---------

Co-authored-by: Gavin.Wu <gavin.guohao.wu@kingland.com>

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

@@ -10,6 +10,7 @@ public enum VendorExtension {
     X_DISCRIMINATOR_VALUE("x-discriminator-value", ExtensionLevel.MODEL, "Used with model inheritance to specify value for discriminator that identifies current model", ""),
     X_SETTER_EXTRA_ANNOTATION("x-setter-extra-annotation", ExtensionLevel.FIELD, "Custom annotation that can be specified over java setter for specific field", "When field is array & uniqueItems, then this extension is used to add `@JsonDeserialize(as = LinkedHashSet.class)` over setter, otherwise no value"),
     X_WEBCLIENT_BLOCKING("x-webclient-blocking", ExtensionLevel.OPERATION, "Specifies if method for specific operation should be blocking or non-blocking(ex: return `Mono<T>/Flux<T>` or `return T/List<T>/Set<T>` & execute `.block()` inside generated method)", "false"),
+    X_WEBCLIENT_RETURN_EXCEPT_LIST_OF_STRING("x-webclient-return-except-list-of-string", ExtensionLevel.OPERATION, "Specifies if method for specific operation should return the type except List<String> and Set<String>(ex: return type expect the `Mono<List<String>>/Flux<List<String>>` and `Mono<Set<String>>/Flux<Set<String>>`)", "false"),
     X_TAGS("x-tags", ExtensionLevel.OPERATION, "Specify multiple swagger tags for operation", null),
     X_ACCEPTS("x-accepts", ExtensionLevel.OPERATION, "Specify custom value for 'Accept' header for operation", null),
     X_CONTENT_TYPE("x-content-type", ExtensionLevel.OPERATION, "Specify custom value for 'Content-Type' header for operation", null),

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

@@ -885,6 +885,10 @@ public class JavaClientCodegen extends AbstractJavaCodegen
                     if (!operation.vendorExtensions.containsKey(VendorExtension.X_WEBCLIENT_BLOCKING.getName()) && webclientBlockingOperations) {
                         operation.vendorExtensions.put(VendorExtension.X_WEBCLIENT_BLOCKING.getName(), true);
                     }
+
+                    if (operation.isArray && !"string".equalsIgnoreCase(operation.returnBaseType)) {
+                        operation.vendorExtensions.put(VendorExtension.X_WEBCLIENT_RETURN_EXCEPT_LIST_OF_STRING.getName(), true);
+                    }
                 }
             }
         }

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

@@ -129,7 +129,7 @@ public class {{classname}} {
 
         String[] localVarAuthNames = new String[] { {{#authMethods}}"{{name}}"{{^-last}}, {{/-last}}{{/authMethods}} };
 
-        {{#returnType}}ParameterizedTypeReference<{{#isArray}}{{{returnBaseType}}}{{/isArray}}{{^isArray}}{{{returnType}}}{{/isArray}}> localVarReturnType = new ParameterizedTypeReference<{{#isArray}}{{{returnBaseType}}}{{/isArray}}{{^isArray}}{{{returnType}}}{{/isArray}}>() {};{{/returnType}}{{^returnType}}ParameterizedTypeReference<Void> localVarReturnType = new ParameterizedTypeReference<Void>() {};{{/returnType}}
+        {{#returnType}}ParameterizedTypeReference<{{#vendorExtensions.x-webclient-return-except-list-of-string}}{{{returnBaseType}}}{{/vendorExtensions.x-webclient-return-except-list-of-string}}{{^vendorExtensions.x-webclient-return-except-list-of-string}}{{{returnType}}}{{/vendorExtensions.x-webclient-return-except-list-of-string}}> localVarReturnType = new ParameterizedTypeReference<{{#vendorExtensions.x-webclient-return-except-list-of-string}}{{{returnBaseType}}}{{/vendorExtensions.x-webclient-return-except-list-of-string}}{{^vendorExtensions.x-webclient-return-except-list-of-string}}{{{returnType}}}{{/vendorExtensions.x-webclient-return-except-list-of-string}}>() {};{{/returnType}}{{^returnType}}ParameterizedTypeReference<Void> localVarReturnType = new ParameterizedTypeReference<Void>() {};{{/returnType}}
         return apiClient.invokeAPI("{{{path}}}", HttpMethod.{{httpMethod}}, pathParams, queryParams, postBody, headerParams, cookieParams, formParams, localVarAccept, localVarContentType, localVarAuthNames, localVarReturnType);
     }
 
@@ -145,9 +145,9 @@ public class {{classname}} {
     * @see <a href="{{url}}">{{summary}} Documentation</a>
 {{/externalDocs}}
      */
-    public {{#returnType}}{{#vendorExtensions.x-webclient-blocking}}{{#isArray}}{{#uniqueItems}}Set{{/uniqueItems}}{{^uniqueItems}}List{{/uniqueItems}}<{{{returnBaseType}}}>{{/isArray}}{{^isArray}}{{{returnType}}}{{/isArray}}{{/vendorExtensions.x-webclient-blocking}}{{^vendorExtensions.x-webclient-blocking}}{{#isArray}}Flux<{{{returnBaseType}}}>{{/isArray}}{{^isArray}}Mono<{{{returnType}}}>{{/isArray}}{{/vendorExtensions.x-webclient-blocking}} {{/returnType}}{{^returnType}}{{#vendorExtensions.x-webclient-blocking}}void{{/vendorExtensions.x-webclient-blocking}}{{^vendorExtensions.x-webclient-blocking}}Mono<Void>{{/vendorExtensions.x-webclient-blocking}} {{/returnType}}{{operationId}}({{#allParams}}{{#isFile}}{{#useAbstractionForFiles}}{{#collectionFormat}}java.util.Collection<org.springframework.core.io.AbstractResource>{{/collectionFormat}}{{^collectionFormat}}org.springframework.core.io.AbstractResource{{/collectionFormat}}{{/useAbstractionForFiles}}{{^useAbstractionForFiles}}{{{dataType}}}{{/useAbstractionForFiles}}{{/isFile}}{{^isFile}}{{{dataType}}}{{/isFile}} {{paramName}}{{^-last}}, {{/-last}}{{/allParams}}) throws WebClientResponseException {
+    public {{#returnType}}{{#vendorExtensions.x-webclient-blocking}}{{#vendorExtensions.x-webclient-return-except-list-of-string}}{{#uniqueItems}}Set{{/uniqueItems}}{{^uniqueItems}}List{{/uniqueItems}}<{{{returnBaseType}}}>{{/vendorExtensions.x-webclient-return-except-list-of-string}}{{^vendorExtensions.x-webclient-return-except-list-of-string}}{{{returnType}}}{{/vendorExtensions.x-webclient-return-except-list-of-string}}{{/vendorExtensions.x-webclient-blocking}}{{^vendorExtensions.x-webclient-blocking}}{{#vendorExtensions.x-webclient-return-except-list-of-string}}Flux<{{{returnBaseType}}}>{{/vendorExtensions.x-webclient-return-except-list-of-string}}{{^vendorExtensions.x-webclient-return-except-list-of-string}}Mono<{{{returnType}}}>{{/vendorExtensions.x-webclient-return-except-list-of-string}}{{/vendorExtensions.x-webclient-blocking}} {{/returnType}}{{^returnType}}{{#vendorExtensions.x-webclient-blocking}}void{{/vendorExtensions.x-webclient-blocking}}{{^vendorExtensions.x-webclient-blocking}}Mono<Void>{{/vendorExtensions.x-webclient-blocking}} {{/returnType}}{{operationId}}({{#allParams}}{{#isFile}}{{#useAbstractionForFiles}}{{#collectionFormat}}java.util.Collection<org.springframework.core.io.AbstractResource>{{/collectionFormat}}{{^collectionFormat}}org.springframework.core.io.AbstractResource{{/collectionFormat}}{{/useAbstractionForFiles}}{{^useAbstractionForFiles}}{{{dataType}}}{{/useAbstractionForFiles}}{{/isFile}}{{^isFile}}{{{dataType}}}{{/isFile}} {{paramName}}{{^-last}}, {{/-last}}{{/allParams}}) throws WebClientResponseException {
-        {{#returnType}}ParameterizedTypeReference<{{#isArray}}{{{returnBaseType}}}{{/isArray}}{{^isArray}}{{{returnType}}}{{/isArray}}> localVarReturnType = new ParameterizedTypeReference<{{#isArray}}{{{returnBaseType}}}{{/isArray}}{{^isArray}}{{{returnType}}}{{/isArray}}>() {};{{/returnType}}{{^returnType}}ParameterizedTypeReference<Void> localVarReturnType = new ParameterizedTypeReference<Void>() {};{{/returnType}}
+        {{#returnType}}ParameterizedTypeReference<{{#vendorExtensions.x-webclient-return-except-list-of-string}}{{{returnBaseType}}}{{/vendorExtensions.x-webclient-return-except-list-of-string}}{{^vendorExtensions.x-webclient-return-except-list-of-string}}{{{returnType}}}{{/vendorExtensions.x-webclient-return-except-list-of-string}}> localVarReturnType = new ParameterizedTypeReference<{{#vendorExtensions.x-webclient-return-except-list-of-string}}{{{returnBaseType}}}{{/vendorExtensions.x-webclient-return-except-list-of-string}}{{^vendorExtensions.x-webclient-return-except-list-of-string}}{{{returnType}}}{{/vendorExtensions.x-webclient-return-except-list-of-string}}>() {};{{/returnType}}{{^returnType}}ParameterizedTypeReference<Void> localVarReturnType = new ParameterizedTypeReference<Void>() {};{{/returnType}}
-        {{^returnType}}{{^vendorExtensions.x-webclient-blocking}}return {{/vendorExtensions.x-webclient-blocking}}{{/returnType}}{{#returnType}}return {{/returnType}}{{operationId}}RequestCreation({{#allParams}}{{paramName}}{{^-last}}, {{/-last}}{{/allParams}}).{{#isArray}}bodyToFlux{{/isArray}}{{^isArray}}bodyToMono{{/isArray}}(localVarReturnType){{#vendorExtensions.x-webclient-blocking}}{{#isArray}}{{#uniqueItems}}.collect(Collectors.toSet()){{/uniqueItems}}{{^uniqueItems}}.collectList(){{/uniqueItems}}{{/isArray}}.block(){{/vendorExtensions.x-webclient-blocking}};
+        {{^returnType}}{{^vendorExtensions.x-webclient-blocking}}return {{/vendorExtensions.x-webclient-blocking}}{{/returnType}}{{#returnType}}return {{/returnType}}{{operationId}}RequestCreation({{#allParams}}{{paramName}}{{^-last}}, {{/-last}}{{/allParams}}).{{#vendorExtensions.x-webclient-return-except-list-of-string}}bodyToFlux{{/vendorExtensions.x-webclient-return-except-list-of-string}}{{^vendorExtensions.x-webclient-return-except-list-of-string}}bodyToMono{{/vendorExtensions.x-webclient-return-except-list-of-string}}(localVarReturnType){{#vendorExtensions.x-webclient-blocking}}{{#vendorExtensions.x-webclient-return-except-list-of-string}}{{#uniqueItems}}.collect(Collectors.toSet()){{/uniqueItems}}{{^uniqueItems}}.collectList(){{/uniqueItems}}{{/vendorExtensions.x-webclient-return-except-list-of-string}}.block(){{/vendorExtensions.x-webclient-blocking}};
     }
 
     /**
@@ -162,9 +162,9 @@ public class {{classname}} {
      * @see <a href="{{url}}">{{summary}} Documentation</a>
 {{/externalDocs}}
      */
-    public {{#vendorExtensions.x-webclient-blocking}}{{#returnType}}{{#isArray}}ResponseEntity<List<{{{returnBaseType}}}>>{{/isArray}}{{^isArray}}ResponseEntity<{{{returnType}}}>{{/isArray}}{{/returnType}}{{^returnType}}ResponseEntity<Void>{{/returnType}} {{/vendorExtensions.x-webclient-blocking}}{{^vendorExtensions.x-webclient-blocking}}{{#returnType}}{{#isArray}}Mono<ResponseEntity<List<{{{returnBaseType}}}>>>{{/isArray}}{{^isArray}}Mono<ResponseEntity<{{{returnType}}}>>{{/isArray}}{{/returnType}}{{^returnType}}Mono<ResponseEntity<Void>>{{/returnType}} {{/vendorExtensions.x-webclient-blocking}}{{operationId}}WithHttpInfo({{#allParams}}{{#isFile}}{{#useAbstractionForFiles}}{{#collectionFormat}}java.util.Collection<org.springframework.core.io.AbstractResource>{{/collectionFormat}}{{^collectionFormat}}org.springframework.core.io.AbstractResource{{/collectionFormat}}{{/useAbstractionForFiles}}{{^useAbstractionForFiles}}{{{dataType}}}{{/useAbstractionForFiles}}{{/isFile}}{{^isFile}}{{{dataType}}}{{/isFile}} {{paramName}}{{^-last}}, {{/-last}}{{/allParams}}) throws WebClientResponseException {
+    public {{#vendorExtensions.x-webclient-blocking}}{{#returnType}}{{#vendorExtensions.x-webclient-return-except-list-of-string}}ResponseEntity<List<{{{returnBaseType}}}>>{{/vendorExtensions.x-webclient-return-except-list-of-string}}{{^vendorExtensions.x-webclient-return-except-list-of-string}}ResponseEntity<{{{returnType}}}>{{/vendorExtensions.x-webclient-return-except-list-of-string}}{{/returnType}}{{^returnType}}ResponseEntity<Void>{{/returnType}} {{/vendorExtensions.x-webclient-blocking}}{{^vendorExtensions.x-webclient-blocking}}{{#returnType}}{{#vendorExtensions.x-webclient-return-except-list-of-string}}Mono<ResponseEntity<List<{{{returnBaseType}}}>>>{{/vendorExtensions.x-webclient-return-except-list-of-string}}{{^vendorExtensions.x-webclient-return-except-list-of-string}}Mono<ResponseEntity<{{{returnType}}}>>{{/vendorExtensions.x-webclient-return-except-list-of-string}}{{/returnType}}{{^returnType}}Mono<ResponseEntity<Void>>{{/returnType}} {{/vendorExtensions.x-webclient-blocking}}{{operationId}}WithHttpInfo({{#allParams}}{{#isFile}}{{#useAbstractionForFiles}}{{#collectionFormat}}java.util.Collection<org.springframework.core.io.AbstractResource>{{/collectionFormat}}{{^collectionFormat}}org.springframework.core.io.AbstractResource{{/collectionFormat}}{{/useAbstractionForFiles}}{{^useAbstractionForFiles}}{{{dataType}}}{{/useAbstractionForFiles}}{{/isFile}}{{^isFile}}{{{dataType}}}{{/isFile}} {{paramName}}{{^-last}}, {{/-last}}{{/allParams}}) throws WebClientResponseException {
-        {{#returnType}}ParameterizedTypeReference<{{#isArray}}{{{returnBaseType}}}{{/isArray}}{{^isArray}}{{{returnType}}}{{/isArray}}> localVarReturnType = new ParameterizedTypeReference<{{#isArray}}{{{returnBaseType}}}{{/isArray}}{{^isArray}}{{{returnType}}}{{/isArray}}>() {};{{/returnType}}{{^returnType}}ParameterizedTypeReference<Void> localVarReturnType = new ParameterizedTypeReference<Void>() {};{{/returnType}}
+        {{#returnType}}ParameterizedTypeReference<{{#vendorExtensions.x-webclient-return-except-list-of-string}}{{{returnBaseType}}}{{/vendorExtensions.x-webclient-return-except-list-of-string}}{{^vendorExtensions.x-webclient-return-except-list-of-string}}{{{returnType}}}{{/vendorExtensions.x-webclient-return-except-list-of-string}}> localVarReturnType = new ParameterizedTypeReference<{{#vendorExtensions.x-webclient-return-except-list-of-string}}{{{returnBaseType}}}{{/vendorExtensions.x-webclient-return-except-list-of-string}}{{^vendorExtensions.x-webclient-return-except-list-of-string}}{{{returnType}}}{{/vendorExtensions.x-webclient-return-except-list-of-string}}>() {};{{/returnType}}{{^returnType}}ParameterizedTypeReference<Void> localVarReturnType = new ParameterizedTypeReference<Void>() {};{{/returnType}}
-        return {{operationId}}RequestCreation({{#allParams}}{{paramName}}{{^-last}}, {{/-last}}{{/allParams}}).{{#isArray}}toEntityList{{/isArray}}{{^isArray}}toEntity{{/isArray}}(localVarReturnType){{#vendorExtensions.x-webclient-blocking}}.block(){{/vendorExtensions.x-webclient-blocking}};
+        return {{operationId}}RequestCreation({{#allParams}}{{paramName}}{{^-last}}, {{/-last}}{{/allParams}}).{{#vendorExtensions.x-webclient-return-except-list-of-string}}toEntityList{{/vendorExtensions.x-webclient-return-except-list-of-string}}{{^vendorExtensions.x-webclient-return-except-list-of-string}}toEntity{{/vendorExtensions.x-webclient-return-except-list-of-string}}(localVarReturnType){{#vendorExtensions.x-webclient-blocking}}.block(){{/vendorExtensions.x-webclient-blocking}};
     }
 
     /**

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

@@ -32,7 +32,7 @@ public class {{classname}}Test {
         {{#allParams}}
         {{#isFile}}{{#useAbstractionForFiles}}{{#collectionFormat}}java.util.Collection<org.springframework.core.io.AbstractResource>{{/collectionFormat}}{{^collectionFormat}}org.springframework.core.io.AbstractResource{{/collectionFormat}}{{/useAbstractionForFiles}}{{^useAbstractionForFiles}}{{{dataType}}}{{/useAbstractionForFiles}}{{/isFile}}{{^isFile}}{{{dataType}}}{{/isFile}} {{paramName}} = null;
         {{/allParams}}
-        {{#returnType}}{{{.}}} response = {{/returnType}}api.{{operationId}}({{#allParams}}{{paramName}}{{^-last}}, {{/-last}}{{/allParams}}){{^vendorExtensions.x-webclient-blocking}}{{#isArray}}{{#uniqueItems}}.collect(Collectors.toSet()){{/uniqueItems}}{{^uniqueItems}}.collectList(){{/uniqueItems}}.block(){{/isArray}}{{^isArray}}.block(){{/isArray}}{{/vendorExtensions.x-webclient-blocking}};
+        {{#returnType}}{{{.}}} response = {{/returnType}}api.{{operationId}}({{#allParams}}{{paramName}}{{^-last}}, {{/-last}}{{/allParams}}){{^vendorExtensions.x-webclient-blocking}}{{#vendorExtensions.x-webclient-return-except-list-of-string}}{{#uniqueItems}}.collect(Collectors.toSet()){{/uniqueItems}}{{^uniqueItems}}.collectList(){{/uniqueItems}}.block(){{/vendorExtensions.x-webclient-return-except-list-of-string}}{{^vendorExtensions.x-webclient-return-except-list-of-string}}.block(){{/vendorExtensions.x-webclient-return-except-list-of-string}}{{/vendorExtensions.x-webclient-blocking}};
 
         // TODO: test validations
     }

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

@@ -2277,4 +2277,38 @@ public class JavaClientCodegenTest {
 
         // shouldn't throw stackoverflow exception
     }
+
+    @Test
+    public void testWebClientSupportListOfStringReturnType_issue7118() throws IOException {
+        Map<String, Object> properties = new HashMap<>();
+        properties.put(CodegenConstants.API_PACKAGE, "xyz.abcdef.api");
+        properties.put(JavaClientCodegen.USE_ABSTRACTION_FOR_FILES, true);
+
+        File output = Files.createTempDirectory("test").toFile();
+        output.deleteOnExit();
+
+        final CodegenConfigurator configurator = new CodegenConfigurator()
+                .setGeneratorName("java")
+                .setLibrary(JavaClientCodegen.WEBCLIENT)
+                .setAdditionalProperties(properties)
+                .setInputSpec("src/test/resources/bugs/issue_7118.yaml")
+                .setOutputDir(output.getAbsolutePath().replace("\\", "/"));
+
+        DefaultGenerator generator = new DefaultGenerator();
+        List<File> files = generator.opts(configurator.toClientOptInput()).generate();
+        files.forEach(File::deleteOnExit);
+
+        validateJavaSourceFiles(files);
+
+        Path userApi = Paths.get(output + "/src/main/java/xyz/abcdef/api/UsersApi.java");
+        TestUtils.assertFileContains(userApi,
+                // set of string
+                "ParameterizedTypeReference<Set<String>> localVarReturnType = new ParameterizedTypeReference<Set<String>>() {};",
+                "getUserIdSetRequestCreation().toEntity(localVarReturnType)",
+                // list of string
+                "ParameterizedTypeReference<List<String>> localVarReturnType = new ParameterizedTypeReference<List<String>>() {};",
+                "getUserIdListRequestCreation().toEntity(localVarReturnType)"
+        );
+    }
+
 }

modules/openapi-generator/src/test/resources/bugs/issue_7118.yaml

@@ -0,0 +1,38 @@
+openapi: 3.0.1
+info:
+  title: OpenAPI Petstore
+  description: "sample to get all user id as string list and string set"
+  version: 1.0.0
+tags: []
+paths:
+  /users/id?type=set:
+    get:
+      operationId: getUserIdSet
+      tags:
+      - users
+      responses:
+        '200':
+          description: response
+          content:
+            application/json:
+              schema:
+                type: array
+                "uniqueItems": true
+                "items":
+                  "type": "string"
+
+  /users/id?type=list:
+    get:
+      operationId: getUserIdList
+      tags:
+        - users
+      responses:
+        '200':
+          description: response
+          content:
+            application/json:
+              schema:
+                type: array
+                "uniqueItems": false
+                "items":
+                  "type": "string"