NPE in JavaClientCodegen when having #/components/ prefixes #731

Signed-off-by: Rudolf Brisuda <[email protected]>

Author: Rudolf Brisuda

src/main/java/io/swagger/codegen/v3/generators/java/JavaClientCodegen.java

@@ -524,7 +524,7 @@ protected List<Map<String, Object>> modelInheritanceSupportInGson(List<?> allMod
             List<Map<String, Object>> childrenList = new ArrayList<>();
             Map<String, Object> parent = new HashMap<>();
             parent.put("classname", parentModel.classname);
-            List<CodegenModel> childrenModels = byParent.get(parentModel);
+            List<CodegenModel> childrenModels = parentModelEntry.getValue();
             for (CodegenModel model : childrenModels) {
                 Map<String, Object> child = new HashMap<>();
                 child.put("name", model.name);

src/test/java/io/swagger/codegen/v3/generators/java/JavaModelTest.java

@@ -1055,4 +1055,22 @@ public void generateModel() throws Exception {
         folder.delete();
     }
 
+    @Test
+    public void generateModelDiscriminatorOrderSchemas() throws Exception {
+        folder.create();
+        final File output = folder.getRoot();
+
+        final CodegenConfigurator configurator = new CodegenConfigurator()
+            .setLang("java")
+            .setInputSpecURL("src/test/resources/3_0_0/discriminator_order_schemas.yaml")
+            .setOutputDir(output.getAbsolutePath());
+
+        final ClientOptInput clientOptInput = configurator.toClientOptInput();
+        new DefaultGenerator().opts(clientOptInput).generate();
+
+        File orderFile = new File(output, "src/main/java/io/swagger/client/model/DSubSubSubBase.java");
+        Assert.assertTrue(orderFile.exists());
+        folder.delete();
+    }
+
 }

src/test/resources/3_0_0/discriminator_order_schemas.yaml

@@ -0,0 +1,58 @@
+openapi: 3.0.2
+info:
+  title: OAI Specification example for NPE
+  version: 1.0.0
+paths:
+  /sampleObjectResponse:
+    get:
+      responses:
+        '200':
+          description: desc
+          content:
+            application/json:
+              schema:
+                $ref: '#/components/schemas/A_Base'
+components:
+  schemas:
+
+    A_Base:
+      type: object
+      properties:
+        relations:
+          type: string
+
+    B_Sub_Base:
+      allOf:
+        - "$ref": '#/components/schemas/A_Base'
+      type: object
+      required:
+        - type
+      properties:
+        type:
+          type: string
+      discriminator:
+        propertyName: type
+        mapping:
+          aPersonalProperty: '#/components/schemas/APersonalProperty'
+
+    C_Sub_Sub_Base:
+      allOf:
+        - "$ref": '#/components/schemas/B_Sub_Base'
+        - required:
+            - type
+          type: object
+          properties:
+            type:
+              type: string
+          discriminator:
+            propertyName: type
+            mapping:
+              motorVehicle: '#/components/schemas/D_Sub_Sub_Sub_Base'
+
+    D_Sub_Sub_Sub_Base:
+      allOf:
+        - "$ref": '#/components/schemas/C_Sub_Sub_Base'
+        - type: object
+          properties:
+            bark:
+              type: string