Fix the Java generator to generate valid @RequestMappings where the produce field takes list of string parameters instead of a single comma-separated string

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

@@ -1784,7 +1784,7 @@ public void preprocessOpenAPI(OpenAPI openAPI) {
                         String contentType = consumes.isEmpty() ? defaultContentType : consumes.get(0);
                         operation.addExtension("x-content-type", contentType);
                     }
-                    String accepts = getAccepts(openAPI, operation);
+                    String[] accepts = getAccepts(openAPI, operation);
                     operation.addExtension("x-accepts", accepts);
                 }
             }
@@ -1835,19 +1835,12 @@ public void preprocessOpenAPI(OpenAPI openAPI) {
         }
     }
 
-    private static String getAccepts(OpenAPI openAPIArg, Operation operation) {
+    private static String[] getAccepts(OpenAPI openAPIArg, Operation operation) {
         final Set<String> producesInfo = getProducesInfo(openAPIArg, operation);
         if (producesInfo != null && !producesInfo.isEmpty()) {
-            StringBuilder sb = new StringBuilder();
-            for (String produce : producesInfo) {
-                if (sb.length() > 0) {
-                    sb.append(",");
-                }
-                sb.append(produce);
-            }
-            return sb.toString();
+            return producesInfo.toArray(new String[] {});
         }
-        return "application/json"; // default media type
+        return new String[] { "application/json" }; // default media type
     }
 
     @Override

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

@@ -43,7 +43,7 @@ public interface {{classname}} extends ApiClient.Api {
   @RequestLine("{{httpMethod}} {{{path}}}{{#hasQueryParams}}?{{/hasQueryParams}}{{#queryParams}}{{baseName}}={{=<% %>=}}{<%paramName%>}<%={{ }}=%>{{^-last}}&{{/-last}}{{/queryParams}}")
   @Headers({
 {{#vendorExtensions.x-content-type}}    "Content-Type: {{vendorExtensions.x-content-type}}",
-{{/vendorExtensions.x-content-type}}    "Accept: {{vendorExtensions.x-accepts}}",{{#headerParams}}
+{{/vendorExtensions.x-content-type}}    "Accept: {{#vendorExtensions.x-accepts}}{{.}}{{^-last}},{{/-last}}{{/vendorExtensions.x-accepts}}",{{#headerParams}}
     "{{baseName}}: {{=<% %>=}}{<%paramName%>}<%={{ }}=%>"{{^-last}},
     {{/-last}}{{/headerParams}}
   })
@@ -73,7 +73,7 @@ public interface {{classname}} extends ApiClient.Api {
   @RequestLine("{{httpMethod}} {{{path}}}{{#hasQueryParams}}?{{/hasQueryParams}}{{#queryParams}}{{baseName}}={{=<% %>=}}{<%paramName%>}<%={{ }}=%>{{^-last}}&{{/-last}}{{/queryParams}}")
   @Headers({
 {{#vendorExtensions.x-content-type}}    "Content-Type: {{vendorExtensions.x-content-type}}",
-{{/vendorExtensions.x-content-type}}    "Accept: {{vendorExtensions.x-accepts}}",{{#headerParams}}
+{{/vendorExtensions.x-content-type}}    "Accept: {{#vendorExtensions.x-accepts}}{{.}}{{^-last}},{{/-last}}{{/vendorExtensions.x-accepts}}",{{#headerParams}}
     "{{baseName}}: {{=<% %>=}}{<%paramName%>}<%={{ }}=%>"{{^-last}},
     {{/-last}}{{/headerParams}}
   })
@@ -118,7 +118,7 @@ public interface {{classname}} extends ApiClient.Api {
   @RequestLine("{{httpMethod}} {{{path}}}?{{#queryParams}}{{baseName}}={{=<% %>=}}{<%paramName%>}<%={{ }}=%>{{^-last}}&{{/-last}}{{/queryParams}}")
   @Headers({
 {{#vendorExtensions.x-content-type}}  "Content-Type: {{vendorExtensions.x-content-type}}",
-{{/vendorExtensions.x-content-type}}  "Accept: {{vendorExtensions.x-accepts}}",{{#headerParams}}
+{{/vendorExtensions.x-content-type}}  "Accept: {{#vendorExtensions.x-accepts}}{{.}}{{^-last}},{{/-last}}{{/vendorExtensions.x-accepts}}",{{#headerParams}}
       "{{baseName}}: {{=<% %>=}}{<%paramName%>}<%={{ }}=%>"{{^-last}},
       {{/-last}}{{/headerParams}}
   })
@@ -158,7 +158,7 @@ public interface {{classname}} extends ApiClient.Api {
       @RequestLine("{{httpMethod}} {{{path}}}?{{#queryParams}}{{baseName}}={{=<% %>=}}{<%paramName%>}<%={{ }}=%>{{^-last}}&{{/-last}}{{/queryParams}}")
       @Headers({
   {{#vendorExtensions.x-content-type}}  "Content-Type: {{vendorExtensions.x-content-type}}",
-  {{/vendorExtensions.x-content-type}}  "Accept: {{vendorExtensions.x-accepts}}",{{#headerParams}}
+  {{/vendorExtensions.x-content-type}}  "Accept: {{#vendorExtensions.x-accepts}}{{.}}{{^-last}},{{/-last}}{{/vendorExtensions.x-accepts}}",{{#headerParams}}
           "{{baseName}}: {{=<% %>=}}{<%paramName%>}<%={{ }}=%>"{{^-last}},
       {{/-last}}{{/headerParams}}
       })

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

@@ -157,9 +157,7 @@ public class {{classname}} {
             {{#x-content-type}}
             reqSpec.setContentType("{{x-content-type}}");
             {{/x-content-type}}
-            {{#x-accepts}}
-            reqSpec.setAccept("{{x-accepts}}");
-            {{/x-accepts}}
+            reqSpec.setAccept("{{#x-accepts}}{{.}}{{^-last}},{{/-last}}{{/x-accepts}}");
             {{/vendorExtensions}}
             this.respSpec = new ResponseSpecBuilder();
         }

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

@@ -233,7 +233,7 @@ public interface {{classname}} {
     @RequestMapping(
         method = RequestMethod.{{httpMethod}},
         value = "{{{path}}}"{{#singleContentTypes}}{{#hasProduces}},
-        produces = "{{{vendorExtensions.x-accepts}}}"{{/hasProduces}}{{#hasConsumes}},
+        produces = { {{#vendorExtensions.x-accepts}}"{{.}}"{{^-last}}, {{/-last}}{{/vendorExtensions.x-accepts}} }{{/hasProduces}}{{#hasConsumes}},
         consumes = "{{{vendorExtensions.x-content-type}}}"{{/hasConsumes}}{{/singleContentTypes}}{{^singleContentTypes}}{{#hasProduces}},
         produces = { {{#produces}}"{{{mediaType}}}"{{^-last}}, {{/-last}}{{/produces}} }{{/hasProduces}}{{#hasConsumes}},
         consumes = { {{#consumes}}"{{{mediaType}}}"{{^-last}}, {{/-last}}{{/consumes}} }{{/hasConsumes}}{{/singleContentTypes}}{{#hasVersionHeaders}},

modules/openapi-generator/src/main/resources/JavaSpring/libraries/spring-http-interface/api.mustache

@@ -53,8 +53,8 @@ public interface {{classname}} {
     {{/isDeprecated}}
     @HttpExchange(
         method = "{{{httpMethod}}}",
-        value = "{{{path}}}"{{#vendorExtensions.x-accepts}},
-        accept = "{{{vendorExtensions.x-accepts}}}"{{/vendorExtensions.x-accepts}}{{#vendorExtensions.x-content-type}},
+        value = "{{{path}}}",
+        accept = { {{#vendorExtensions.x-accepts}}"{{.}}"{{^-last}}, {{/-last}}{{/vendorExtensions.x-accepts}} }{{#vendorExtensions.x-content-type}},
         contentType = "{{{vendorExtensions.x-content-type}}}"{{/vendorExtensions.x-content-type}}
     )
     {{>responseType}} {{operationId}}(

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

@@ -58,7 +58,7 @@ public interface {{classname}} {
     @RequestMapping(
         method = RequestMethod.{{httpMethod}},
         value = "{{{path}}}"{{#singleContentTypes}},
-        produces = "{{{vendorExtensions.x-accepts}}}",
+        produces = { {{#vendorExtensions.x-accepts}}"{{.}}"{{^-last}}, {{/-last}}{{/vendorExtensions.x-accepts}} },
         consumes = "{{{vendorExtensions.x-content-type}}}"{{/singleContentTypes}}{{^singleContentTypes}}{{#hasProduces}},
         produces = { {{#produces}}"{{{mediaType}}}"{{^-last}}, {{/-last}}{{/produces}} }{{/hasProduces}}{{#hasConsumes}},
         consumes = { {{#consumes}}"{{{mediaType}}}"{{^-last}}, {{/-last}}{{/consumes}} }{{/hasConsumes}}{{/singleContentTypes}}

modules/openapi-generator/src/main/resources/kotlin-spring/api.mustache

@@ -85,7 +85,7 @@ class {{classname}}Controller({{#serviceInterface}}@Autowired(required = true) v
     @RequestMapping(
         method = [RequestMethod.{{httpMethod}}],
         value = ["{{#lambdaEscapeInNormalString}}{{path}}{{/lambdaEscapeInNormalString}}"]{{#singleContentTypes}}{{#hasProduces}},
-        produces = "{{{vendorExtensions.x-accepts}}}"{{/hasProduces}}{{#hasConsumes}},
+        produces = [{{#vendorExtensions.x-accepts}}"{{.}}"{{^-last}}, {{/-last}}{{/vendorExtensions.x-accepts}}]{{/hasProduces}}{{#hasConsumes}},
         consumes = "{{{vendorExtensions.x-content-type}}}"{{/hasConsumes}}{{/singleContentTypes}}{{^singleContentTypes}}{{#hasProduces}},
         produces = [{{#produces}}"{{{mediaType}}}"{{^-last}}, {{/-last}}{{/produces}}]{{/hasProduces}}{{#hasConsumes}},
         consumes = [{{#consumes}}"{{{mediaType}}}"{{^-last}}, {{/-last}}{{/consumes}}]{{/hasConsumes}}{{/singleContentTypes}}

modules/openapi-generator/src/main/resources/kotlin-spring/apiInterface.mustache

@@ -97,7 +97,7 @@ interface {{classname}} {
     @RequestMapping(
             method = [RequestMethod.{{httpMethod}}],
             value = ["{{#lambdaEscapeInNormalString}}{{path}}{{/lambdaEscapeInNormalString}}"]{{#singleContentTypes}}{{#hasProduces}},
-            produces = "{{{vendorExtensions.x-accepts}}}"{{/hasProduces}}{{#hasConsumes}},
+            produces = [{{#vendorExtensions.x-accepts}}"{{.}}"{{^-last}}, {{/-last}}{{/vendorExtensions.x-accepts}}]{{/hasProduces}}{{#hasConsumes}},
             consumes = "{{{vendorExtensions.x-content-type}}}"{{/hasConsumes}}{{/singleContentTypes}}{{^singleContentTypes}}{{#hasProduces}},
             produces = [{{#produces}}"{{{mediaType}}}"{{^-last}}, {{/-last}}{{/produces}}]{{/hasProduces}}{{#hasConsumes}},
             consumes = [{{#consumes}}"{{{mediaType}}}"{{^-last}}, {{/-last}}{{/consumes}}]{{/hasConsumes}}{{/singleContentTypes}}

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

@@ -83,7 +83,10 @@ public void testPreprocessOpenApiIncludeAllMediaTypesInAcceptHeader() throws Exc
         codegen.preprocessOpenAPI(openAPI);
 
         Assert.assertEquals(codegen.getArtifactVersion(), openAPI.getInfo().getVersion());
-        Assert.assertEquals(openAPI.getPaths().get("/pet").getPost().getExtensions().get("x-accepts"), "application/json,application/xml");
+
+        Object xAccepts = openAPI.getPaths().get("/pet").getPost().getExtensions().get("x-accepts");
+        Assert.assertTrue(xAccepts instanceof String[]);
+        Assert.assertTrue(List.of((String[]) xAccepts).containsAll(List.of("application/json", "application/xml")));
     }
 
     @Test

samples/client/echo_api/java/apache-httpclient/api/openapi.yaml

@@ -58,7 +58,8 @@ paths:
       summary: Test path parameter(s)
       tags:
       - path
-      x-accepts: text/plain
+      x-accepts:
+      - text/plain
   /form/integer/boolean/string:
     post:
       description: Test form parameter(s)
@@ -79,7 +80,8 @@ paths:
       tags:
       - form
       x-content-type: application/x-www-form-urlencoded
-      x-accepts: text/plain
+      x-accepts:
+      - text/plain
   /form/oneof:
     post:
       description: Test form parameter(s) for oneOf schema
@@ -100,7 +102,8 @@ paths:
       tags:
       - form
       x-content-type: application/x-www-form-urlencoded
-      x-accepts: text/plain
+      x-accepts:
+      - text/plain
   /header/integer/boolean/string/enums:
     get:
       description: Test header parameter(s)
@@ -155,7 +158,8 @@ paths:
       summary: Test header parameter(s)
       tags:
       - header
-      x-accepts: text/plain
+      x-accepts:
+      - text/plain
   /query/enum_ref_string:
     get:
       description: Test query parameter(s)
@@ -189,7 +193,8 @@ paths:
       summary: Test query parameter(s)
       tags:
       - query
-      x-accepts: text/plain
+      x-accepts:
+      - text/plain
   /query/datetime/date/string:
     get:
       description: Test query parameter(s)
@@ -228,7 +233,8 @@ paths:
       summary: Test query parameter(s)
       tags:
       - query
-      x-accepts: text/plain
+      x-accepts:
+      - text/plain
   /query/integer/boolean/string:
     get:
       description: Test query parameter(s)
@@ -265,7 +271,8 @@ paths:
       summary: Test query parameter(s)
       tags:
       - query
-      x-accepts: text/plain
+      x-accepts:
+      - text/plain
   /query/style_form/explode_true/array_string:
     get:
       description: Test query parameter(s)
@@ -288,7 +295,8 @@ paths:
       summary: Test query parameter(s)
       tags:
       - query
-      x-accepts: text/plain
+      x-accepts:
+      - text/plain
   /query/style_form/explode_false/array_integer:
     get:
       description: Test query parameter(s)
@@ -313,7 +321,8 @@ paths:
       summary: Test query parameter(s)
       tags:
       - query
-      x-accepts: text/plain
+      x-accepts:
+      - text/plain
   /query/style_form/explode_false/array_string:
     get:
       description: Test query parameter(s)
@@ -338,7 +347,8 @@ paths:
       summary: Test query parameter(s)
       tags:
       - query
-      x-accepts: text/plain
+      x-accepts:
+      - text/plain
   /query/style_form/explode_true/object:
     get:
       description: Test query parameter(s)
@@ -361,7 +371,8 @@ paths:
       summary: Test query parameter(s)
       tags:
       - query
-      x-accepts: text/plain
+      x-accepts:
+      - text/plain
   /query/style_form/explode_true/object/allOf:
     get:
       description: Test query parameter(s)
@@ -384,7 +395,8 @@ paths:
       summary: Test query parameter(s)
       tags:
       - query
-      x-accepts: text/plain
+      x-accepts:
+      - text/plain
   /query/style_deepObject/explode_true/object:
     get:
       description: Test query parameter(s)
@@ -407,7 +419,8 @@ paths:
       summary: Test query parameter(s)
       tags:
       - query
-      x-accepts: text/plain
+      x-accepts:
+      - text/plain
   /query/style_deepObject/explode_true/object/allOf:
     get:
       description: Test query parameter(s)
@@ -430,7 +443,8 @@ paths:
       summary: Test query parameter(s)
       tags:
       - query
-      x-accepts: text/plain
+      x-accepts:
+      - text/plain
   /body/application/octetstream/binary:
     post:
       description: Test body parameter(s)
@@ -452,7 +466,8 @@ paths:
       tags:
       - body
       x-content-type: application/octet-stream
-      x-accepts: text/plain
+      x-accepts:
+      - text/plain
   /echo/body/Pet:
     post:
       description: Test body parameter(s)
@@ -470,7 +485,8 @@ paths:
       tags:
       - body
       x-content-type: application/json
-      x-accepts: application/json
+      x-accepts:
+      - application/json
   /echo/body/allOf/Pet:
     post:
       description: Test body parameter(s)
@@ -488,7 +504,8 @@ paths:
       tags:
       - body
       x-content-type: application/json
-      x-accepts: application/json
+      x-accepts:
+      - application/json
   /echo/body/Pet/response_string:
     post:
       description: Test empty response body
@@ -506,7 +523,8 @@ paths:
       tags:
       - body
       x-content-type: application/json
-      x-accepts: text/plain
+      x-accepts:
+      - text/plain
   /echo/body/Tag/response_string:
     post:
       description: Test empty json (request body)
@@ -524,7 +542,8 @@ paths:
       tags:
       - body
       x-content-type: application/json
-      x-accepts: text/plain
+      x-accepts:
+      - text/plain
   /echo/body/FreeFormObject/response_string:
     post:
       description: Test free form object
@@ -546,7 +565,8 @@ paths:
       tags:
       - body
       x-content-type: application/json
-      x-accepts: text/plain
+      x-accepts:
+      - text/plain
   /echo/body/string_enum:
     post:
       description: Test string enum response body
@@ -568,7 +588,8 @@ paths:
       tags:
       - body
       x-content-type: application/json
-      x-accepts: application/json
+      x-accepts:
+      - application/json
   /binary/gif:
     post:
       description: Test binary (gif) response body
@@ -584,7 +605,8 @@ paths:
       summary: Test binary (gif) response body
       tags:
       - body
-      x-accepts: image/gif
+      x-accepts:
+      - image/gif
   /body/application/octetstream/single_binary:
     post:
       description: Test single binary in multipart mime
@@ -605,7 +627,8 @@ paths:
       tags:
       - body
       x-content-type: multipart/form-data
-      x-accepts: text/plain
+      x-accepts:
+      - text/plain
   /body/application/octetstream/array_of_binary:
     post:
       description: Test array of binary in multipart mime
@@ -626,7 +649,8 @@ paths:
       tags:
       - body
       x-content-type: multipart/form-data
-      x-accepts: text/plain
+      x-accepts:
+      - text/plain
   /auth/http/basic:
     post:
       description: To test HTTP basic authentication
@@ -643,7 +667,8 @@ paths:
       summary: To test HTTP basic authentication
       tags:
       - auth
-      x-accepts: text/plain
+      x-accepts:
+      - text/plain
   /auth/http/bearer:
     post:
       description: To test HTTP bearer authentication
@@ -660,7 +685,8 @@ paths:
       summary: To test HTTP bearer authentication
       tags:
       - auth
-      x-accepts: text/plain
+      x-accepts:
+      - text/plain
 components:
   requestBodies:
     Pet: