Default nested array to null in java generators (#21713)

* default nested array to null in java generators

* add test schema

Author: wing328

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

@@ -1291,6 +1291,9 @@ public String toArrayDefaultValue(CodegenProperty cp, Schema schema) {
                                     }
                                 })
                                 .collect(Collectors.joining(", "));
+                    } else if (cp.items.isContainer) {
+                        // TODO nested array/set/map is not supported at the moment so defaulting to null
+                        defaultValue = null;
                     } else { // array item is non-string, e.g. integer
                         defaultValue = StringUtils.join(_values, ", ");
                     }

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

@@ -2809,3 +2809,20 @@ components:
           $ref: '#/components/schemas/ArrayOneOf'
         anyof_prop:
           $ref: '#/components/schemas/ArrayAnyOf'
+    NestedArrayWithDefaultValues:
+      type: object
+      properties:
+        nestedArray:
+          type: array
+          items:
+            type: array
+            items:
+              type: string
+            default: ["value1", "value2"]
+          default:
+            [
+              [ "h1", "Header 1" ],
+              [ "h2", "Header 2" ],
+              [ "h3", "Header 3" ],
+              [ "h4", "Header 4" ]
+            ]

samples/client/petstore/java/okhttp-gson/.openapi-generator/FILES

@@ -71,6 +71,7 @@ docs/ModelList.md
 docs/ModelReturn.md
 docs/ModelWithOneOfAnyOfProperties.md
 docs/Name.md
+docs/NestedArrayWithDefaultValues.md
 docs/NewPet.md
 docs/NewPetCategoryInlineAllof.md
 docs/NewPetCategoryInlineAllofAllOfCategoryTag.md
@@ -216,6 +217,7 @@ src/main/java/org/openapitools/client/model/ModelList.java
 src/main/java/org/openapitools/client/model/ModelReturn.java
 src/main/java/org/openapitools/client/model/ModelWithOneOfAnyOfProperties.java
 src/main/java/org/openapitools/client/model/Name.java
+src/main/java/org/openapitools/client/model/NestedArrayWithDefaultValues.java
 src/main/java/org/openapitools/client/model/NewPet.java
 src/main/java/org/openapitools/client/model/NewPetCategoryInlineAllof.java
 src/main/java/org/openapitools/client/model/NewPetCategoryInlineAllofAllOfCategoryTag.java

samples/client/petstore/java/okhttp-gson/README.md

@@ -233,6 +233,7 @@ Class | Method | HTTP request | Description
  - [ModelReturn](docs/ModelReturn.md)
  - [ModelWithOneOfAnyOfProperties](docs/ModelWithOneOfAnyOfProperties.md)
  - [Name](docs/Name.md)
+ - [NestedArrayWithDefaultValues](docs/NestedArrayWithDefaultValues.md)
  - [NewPet](docs/NewPet.md)
  - [NewPetCategoryInlineAllof](docs/NewPetCategoryInlineAllof.md)
  - [NewPetCategoryInlineAllofAllOfCategoryTag](docs/NewPetCategoryInlineAllofAllOfCategoryTag.md)

samples/client/petstore/java/okhttp-gson/api/openapi.yaml

@@ -2916,6 +2916,27 @@ components:
         anyof_prop:
           $ref: "#/components/schemas/ArrayAnyOf"
       type: object
+    NestedArrayWithDefaultValues:
+      properties:
+        nestedArray:
+          default:
+          - - h1
+            - Header 1
+          - - h2
+            - Header 2
+          - - h3
+            - Header 3
+          - - h4
+            - Header 4
+          items:
+            default:
+            - value1
+            - value2
+            items:
+              type: string
+            type: array
+          type: array
+      type: object
     _foo_get_default_response:
       example:
         string:

samples/client/petstore/java/okhttp-gson/docs/NestedArrayWithDefaultValues.md

@@ -0,0 +1,13 @@
+
+
+# NestedArrayWithDefaultValues
+
+
+## Properties
+
+| Name | Type | Description | Notes |
+|------------ | ------------- | ------------- | -------------|
+|**nestedArray** | **List<List<String>>** |  |  [optional] |
+
+
+

samples/client/petstore/java/okhttp-gson/src/main/java/org/openapitools/client/JSON.java

@@ -303,6 +303,7 @@ private static Class getClassByDiscriminator(Map classByDiscriminatorValue, Stri
         gsonBuilder.registerTypeAdapterFactory(new org.openapitools.client.model.ModelReturn.CustomTypeAdapterFactory());
         gsonBuilder.registerTypeAdapterFactory(new org.openapitools.client.model.ModelWithOneOfAnyOfProperties.CustomTypeAdapterFactory());
         gsonBuilder.registerTypeAdapterFactory(new org.openapitools.client.model.Name.CustomTypeAdapterFactory());
+        gsonBuilder.registerTypeAdapterFactory(new org.openapitools.client.model.NestedArrayWithDefaultValues.CustomTypeAdapterFactory());
         gsonBuilder.registerTypeAdapterFactory(new org.openapitools.client.model.NewPet.CustomTypeAdapterFactory());
         gsonBuilder.registerTypeAdapterFactory(new org.openapitools.client.model.NewPetCategoryInlineAllof.CustomTypeAdapterFactory());
         gsonBuilder.registerTypeAdapterFactory(new org.openapitools.client.model.NewPetCategoryInlineAllofAllOfCategoryTag.CustomTypeAdapterFactory());