use map/array model class only if it is generated (#17612)

* fix

* tests

* generate samples

* refactor

samples/client/petstore/java/apache-httpclient/README.md

@@ -129,6 +129,7 @@ Class | Method | HTTP request | Description
 *FakeApi* | [**testJsonFormData**](docs/FakeApi.md#testJsonFormData) | **GET** /fake/jsonFormData | test json serialization of form data
 *FakeApi* | [**testNullable**](docs/FakeApi.md#testNullable) | **POST** /fake/nullable | test nullable parent property
 *FakeApi* | [**testQueryParameterCollectionFormat**](docs/FakeApi.md#testQueryParameterCollectionFormat) | **PUT** /fake/test-query-parameters | 
+*FakeApi* | [**testStringMapReference**](docs/FakeApi.md#testStringMapReference) | **POST** /fake/stringMap-reference | test referenced string map
 *FakeClassnameTags123Api* | [**testClassname**](docs/FakeClassnameTags123Api.md#testClassname) | **PATCH** /fake_classname_test | To test class name in snake case
 *PetApi* | [**addPet**](docs/PetApi.md#addPet) | **POST** /pet | Add a new pet to the store
 *PetApi* | [**deletePet**](docs/PetApi.md#deletePet) | **DELETE** /pet/{petId} | Deletes a pet

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

@@ -1029,6 +1029,25 @@ paths:
       - fake
       x-content-type: application/json
       x-accepts: application/json
+  /fake/stringMap-reference:
+    post:
+      description: ""
+      operationId: testStringMapReference
+      requestBody:
+        content:
+          application/json:
+            schema:
+              $ref: '#/components/schemas/MapOfString'
+        description: request body
+        required: true
+      responses:
+        "200":
+          description: successful operation
+      summary: test referenced string map
+      tags:
+      - fake
+      x-content-type: application/json
+      x-accepts: application/json
   /fake/inline-additionalProperties:
     post:
       description: ""
@@ -1874,6 +1893,11 @@ components:
       additionalProperties: true
       description: A schema consisting only of additional properties
       type: object
+    MapOfString:
+      additionalProperties:
+        type: string
+      description: A schema consisting only of additional properties of type string
+      type: object
     OuterEnum:
       enum:
       - placed

samples/client/petstore/java/apache-httpclient/docs/FakeApi.md

@@ -25,6 +25,7 @@ All URIs are relative to *http://petstore.swagger.io:80/v2*
 | [**testJsonFormData**](FakeApi.md#testJsonFormData) | **GET** /fake/jsonFormData | test json serialization of form data |
 | [**testNullable**](FakeApi.md#testNullable) | **POST** /fake/nullable | test nullable parent property |
 | [**testQueryParameterCollectionFormat**](FakeApi.md#testQueryParameterCollectionFormat) | **PUT** /fake/test-query-parameters |  |
+| [**testStringMapReference**](FakeApi.md#testStringMapReference) | **POST** /fake/stringMap-reference | test referenced string map |
 
 
 
@@ -1473,3 +1474,68 @@ No authorization required
 |-------------|-------------|------------------|
 | **200** | Success |  -  |
 
+
+## testStringMapReference
+
+> testStringMapReference(requestBody)
+
+test referenced string map
+
+
+
+### Example
+
+```java
+// Import classes:
+import org.openapitools.client.ApiClient;
+import org.openapitools.client.ApiException;
+import org.openapitools.client.Configuration;
+import org.openapitools.client.models.*;
+import org.openapitools.client.api.FakeApi;
+
+public class Example {
+    public static void main(String[] args) {
+        ApiClient defaultClient = Configuration.getDefaultApiClient();
+        defaultClient.setBasePath("http://petstore.swagger.io:80/v2");
+
+        FakeApi apiInstance = new FakeApi(defaultClient);
+        Map<String, String> requestBody = new HashMap(); // Map<String, String> | request body
+        try {
+            apiInstance.testStringMapReference(requestBody);
+        } catch (ApiException e) {
+            System.err.println("Exception when calling FakeApi#testStringMapReference");
+            System.err.println("Status code: " + e.getCode());
+            System.err.println("Reason: " + e.getResponseBody());
+            System.err.println("Response headers: " + e.getResponseHeaders());
+            e.printStackTrace();
+        }
+    }
+}
+```
+
+### Parameters
+
+
+| Name | Type | Description  | Notes |
+|------------- | ------------- | ------------- | -------------|
+| **requestBody** | [**Map&lt;String, String&gt;**](String.md)| request body | |
+
+### Return type
+
+null (empty response body)
+
+### Authorization
+
+No authorization required
+
+### HTTP request headers
+
+- **Content-Type**: application/json
+- **Accept**: Not defined
+
+
+### HTTP response details
+| Status code | Description | Response headers |
+|-------------|-------------|------------------|
+| **200** | successful operation |  -  |
+

samples/client/petstore/java/apache-httpclient/src/main/java/org/openapitools/client/api/FakeApi.java

@@ -1737,4 +1737,75 @@ if (param2 != null)
     );
   }
 
+  /**
+   * test referenced string map
+   * 
+   * @param requestBody request body (required)
+   * @throws ApiException if fails to make API call
+   */
+  public void testStringMapReference(Map<String, String> requestBody) throws ApiException {
+    this.testStringMapReference(requestBody, Collections.emptyMap());
+  }
+
+
+  /**
+   * test referenced string map
+   * 
+   * @param requestBody request body (required)
+   * @param additionalHeaders additionalHeaders for this call
+   * @throws ApiException if fails to make API call
+   */
+  public void testStringMapReference(Map<String, String> requestBody, Map<String, String> additionalHeaders) throws ApiException {
+    Object localVarPostBody = requestBody;
+    
+    // verify the required parameter 'requestBody' is set
+    if (requestBody == null) {
+      throw new ApiException(400, "Missing the required parameter 'requestBody' when calling testStringMapReference");
+    }
+    
+    // create path and map variables
+    String localVarPath = "/fake/stringMap-reference";
+
+    StringJoiner localVarQueryStringJoiner = new StringJoiner("&");
+    String localVarQueryParameterBaseName;
+    List<Pair> localVarQueryParams = new ArrayList<Pair>();
+    List<Pair> localVarCollectionQueryParams = new ArrayList<Pair>();
+    Map<String, String> localVarHeaderParams = new HashMap<String, String>();
+    Map<String, String> localVarCookieParams = new HashMap<String, String>();
+    Map<String, Object> localVarFormParams = new HashMap<String, Object>();
+
+    
+    localVarHeaderParams.putAll(additionalHeaders);
+
+    
+    
+    final String[] localVarAccepts = {
+      
+    };
+    final String localVarAccept = apiClient.selectHeaderAccept(localVarAccepts);
+
+    final String[] localVarContentTypes = {
+      "application/json"
+    };
+    final String localVarContentType = apiClient.selectHeaderContentType(localVarContentTypes);
+
+    String[] localVarAuthNames = new String[] {  };
+
+    apiClient.invokeAPI(
+        localVarPath,
+        "POST",
+        localVarQueryParams,
+        localVarCollectionQueryParams,
+        localVarQueryStringJoiner.toString(),
+        localVarPostBody,
+        localVarHeaderParams,
+        localVarCookieParams,
+        localVarFormParams,
+        localVarAccept,
+        localVarContentType,
+        localVarAuthNames,
+        null
+    );
+  }
+
 }