fix: #21345 Java Native Client, handle Byte[] and File response types correctly (#21346)

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

@@ -100,6 +100,54 @@ public class {{classname}} {
     return operationId + " call failed with: " + statusCode + " - " + body;
   }
 
+  /**
+   * Download file from the given response.
+   *
+   * @param response Response
+   * @return File
+   * @throws ApiException If fail to read file content from response and write to disk
+   */
+  public File downloadFileFromResponse(HttpResponse<InputStream> response) throws ApiException {
+    try {
+      File file = prepareDownloadFile(response);
+      java.nio.file.Files.copy(response.body(), file.toPath(), java.nio.file.StandardCopyOption.REPLACE_EXISTING);
+      return file;
+    } catch (IOException e) {
+      throw new ApiException(e);
+    }
+  }
+
+  /**
+   * <p>Prepare the file for download from the response.</p>
+   *
+   * @param response a {@link java.net.http.HttpResponse} object.
+   * @return a {@link java.io.File} object.
+   * @throws java.io.IOException if any.
+   */
+  private File prepareDownloadFile(HttpResponse<InputStream> response) throws IOException {
+    String filename = null;
+    java.util.Optional<String> contentDisposition = response.headers().firstValue("Content-Disposition");
+    if (contentDisposition.isPresent() && !"".equals(contentDisposition.get())) {
+      // Get filename from the Content-Disposition header.
+      java.util.regex.Pattern pattern = java.util.regex.Pattern.compile("filename=['\"]?([^'\"\\s]+)['\"]?");
+      java.util.regex.Matcher matcher = pattern.matcher(contentDisposition.get());
+      if (matcher.find())
+        filename = matcher.group(1);
+    }
+    File file = null;
+    if (filename != null) {
+      java.nio.file.Path tempDir = java.nio.file.Files.createTempDirectory("swagger-gen-native");
+      java.nio.file.Path filePath = java.nio.file.Files.createFile(tempDir.resolve(filename));
+      file = filePath.toFile();
+      tempDir.toFile().deleteOnExit();   // best effort cleanup
+      file.deleteOnExit(); // best effort cleanup
+    } else {
+      file = java.nio.file.Files.createTempFile("download-", "").toFile();
+      file.deleteOnExit(); // best effort cleanup
+    }
+    return file;
+  }
+
   {{#operation}}
   {{#vendorExtensions.x-group-parameters}}
   {{#hasParams}}
@@ -291,13 +339,23 @@ public class {{classname}} {
           );
         }
 
+        {{^isResponseFile}}{{#isResponseBinary}}
+        Byte[] responseValue = localVarResponse.body().readAllBytes();
+        {{/isResponseBinary}}{{/isResponseFile}}
+        {{#isResponseFile}}
+        // Handle file downloading.
+        File responseValue = downloadFileFromResponse(localVarResponse);
+        {{/isResponseFile}}
+        {{^isResponseBinary}}{{^isResponseFile}}
         String responseBody = new String(localVarResponse.body().readAllBytes());
+        {{{returnType}}} responseValue = responseBody.isBlank()? null: memberVarObjectMapper.readValue(responseBody, new TypeReference<{{{returnType}}}>() {});
+        {{/isResponseFile}}{{/isResponseBinary}}
         localVarResponse.body().close();
 
         return new ApiResponse<{{{returnType}}}>(
             localVarResponse.statusCode(),
             localVarResponse.headers().map(),
-            responseBody.isBlank()? null: memberVarObjectMapper.readValue(responseBody, new TypeReference<{{{returnType}}}>() {})
+            responseValue
         );
         {{/returnType}}
         {{^returnType}}

samples/client/echo_api/java/native/src/main/java/org/openapitools/client/api/AuthApi.java

@@ -81,6 +81,54 @@ public class AuthApi {
     return operationId + " call failed with: " + statusCode + " - " + body;
   }
 
+  /**
+   * Download file from the given response.
+   *
+   * @param response Response
+   * @return File
+   * @throws ApiException If fail to read file content from response and write to disk
+   */
+  public File downloadFileFromResponse(HttpResponse<InputStream> response) throws ApiException {
+    try {
+      File file = prepareDownloadFile(response);
+      java.nio.file.Files.copy(response.body(), file.toPath(), java.nio.file.StandardCopyOption.REPLACE_EXISTING);
+      return file;
+    } catch (IOException e) {
+      throw new ApiException(e);
+    }
+  }
+
+  /**
+   * <p>Prepare the file for download from the response.</p>
+   *
+   * @param response a {@link java.net.http.HttpResponse} object.
+   * @return a {@link java.io.File} object.
+   * @throws java.io.IOException if any.
+   */
+  private File prepareDownloadFile(HttpResponse<InputStream> response) throws IOException {
+    String filename = null;
+    java.util.Optional<String> contentDisposition = response.headers().firstValue("Content-Disposition");
+    if (contentDisposition.isPresent() && !"".equals(contentDisposition.get())) {
+      // Get filename from the Content-Disposition header.
+      java.util.regex.Pattern pattern = java.util.regex.Pattern.compile("filename=['\"]?([^'\"\\s]+)['\"]?");
+      java.util.regex.Matcher matcher = pattern.matcher(contentDisposition.get());
+      if (matcher.find())
+        filename = matcher.group(1);
+    }
+    File file = null;
+    if (filename != null) {
+      java.nio.file.Path tempDir = java.nio.file.Files.createTempDirectory("swagger-gen-native");
+      java.nio.file.Path filePath = java.nio.file.Files.createFile(tempDir.resolve(filename));
+      file = filePath.toFile();
+      tempDir.toFile().deleteOnExit();   // best effort cleanup
+      file.deleteOnExit(); // best effort cleanup
+    } else {
+      file = java.nio.file.Files.createTempFile("download-", "").toFile();
+      file.deleteOnExit(); // best effort cleanup
+    }
+    return file;
+  }
+
   /**
    * To test HTTP basic authentication
    * To test HTTP basic authentication

samples/client/echo_api/java/native/src/main/java/org/openapitools/client/api/BodyApi.java

@@ -91,6 +91,54 @@ public class BodyApi {
     return operationId + " call failed with: " + statusCode + " - " + body;
   }
 
+  /**
+   * Download file from the given response.
+   *
+   * @param response Response
+   * @return File
+   * @throws ApiException If fail to read file content from response and write to disk
+   */
+  public File downloadFileFromResponse(HttpResponse<InputStream> response) throws ApiException {
+    try {
+      File file = prepareDownloadFile(response);
+      java.nio.file.Files.copy(response.body(), file.toPath(), java.nio.file.StandardCopyOption.REPLACE_EXISTING);
+      return file;
+    } catch (IOException e) {
+      throw new ApiException(e);
+    }
+  }
+
+  /**
+   * <p>Prepare the file for download from the response.</p>
+   *
+   * @param response a {@link java.net.http.HttpResponse} object.
+   * @return a {@link java.io.File} object.
+   * @throws java.io.IOException if any.
+   */
+  private File prepareDownloadFile(HttpResponse<InputStream> response) throws IOException {
+    String filename = null;
+    java.util.Optional<String> contentDisposition = response.headers().firstValue("Content-Disposition");
+    if (contentDisposition.isPresent() && !"".equals(contentDisposition.get())) {
+      // Get filename from the Content-Disposition header.
+      java.util.regex.Pattern pattern = java.util.regex.Pattern.compile("filename=['\"]?([^'\"\\s]+)['\"]?");
+      java.util.regex.Matcher matcher = pattern.matcher(contentDisposition.get());
+      if (matcher.find())
+        filename = matcher.group(1);
+    }
+    File file = null;
+    if (filename != null) {
+      java.nio.file.Path tempDir = java.nio.file.Files.createTempDirectory("swagger-gen-native");
+      java.nio.file.Path filePath = java.nio.file.Files.createFile(tempDir.resolve(filename));
+      file = filePath.toFile();
+      tempDir.toFile().deleteOnExit();   // best effort cleanup
+      file.deleteOnExit(); // best effort cleanup
+    } else {
+      file = java.nio.file.Files.createTempFile("download-", "").toFile();
+      file.deleteOnExit(); // best effort cleanup
+    }
+    return file;
+  }
+
   /**
    * Test binary (gif) response body
    * Test binary (gif) response body
@@ -129,13 +177,16 @@ public class BodyApi {
           );
         }
 
-        String responseBody = new String(localVarResponse.body().readAllBytes());
+        
+        // Handle file downloading.
+        File responseValue = downloadFileFromResponse(localVarResponse);
+        
         localVarResponse.body().close();
 
         return new ApiResponse<File>(
             localVarResponse.statusCode(),
             localVarResponse.headers().map(),
-            responseBody.isBlank()? null: memberVarObjectMapper.readValue(responseBody, new TypeReference<File>() {})
+            responseValue
         );
       } finally {
       }
@@ -514,13 +565,17 @@ public class BodyApi {
           );
         }
 
+        
+        
         String responseBody = new String(localVarResponse.body().readAllBytes());
+        Pet responseValue = responseBody.isBlank()? null: memberVarObjectMapper.readValue(responseBody, new TypeReference<Pet>() {});
+        
         localVarResponse.body().close();
 
         return new ApiResponse<Pet>(
             localVarResponse.statusCode(),
             localVarResponse.headers().map(),
-            responseBody.isBlank()? null: memberVarObjectMapper.readValue(responseBody, new TypeReference<Pet>() {})
+            responseValue
         );
       } finally {
       }
@@ -681,13 +736,17 @@ public class BodyApi {
           );
         }
 
+        
+        
         String responseBody = new String(localVarResponse.body().readAllBytes());
+        Pet responseValue = responseBody.isBlank()? null: memberVarObjectMapper.readValue(responseBody, new TypeReference<Pet>() {});
+        
         localVarResponse.body().close();
 
         return new ApiResponse<Pet>(
             localVarResponse.statusCode(),
             localVarResponse.headers().map(),
-            responseBody.isBlank()? null: memberVarObjectMapper.readValue(responseBody, new TypeReference<Pet>() {})
+            responseValue
         );
       } finally {
       }
@@ -848,13 +907,17 @@ public class BodyApi {
           );
         }
 
+        
+        
         String responseBody = new String(localVarResponse.body().readAllBytes());
+        StringEnumRef responseValue = responseBody.isBlank()? null: memberVarObjectMapper.readValue(responseBody, new TypeReference<StringEnumRef>() {});
+        
         localVarResponse.body().close();
 
         return new ApiResponse<StringEnumRef>(
             localVarResponse.statusCode(),
             localVarResponse.headers().map(),
-            responseBody.isBlank()? null: memberVarObjectMapper.readValue(responseBody, new TypeReference<StringEnumRef>() {})
+            responseValue
         );
       } finally {
       }

samples/client/echo_api/java/native/src/main/java/org/openapitools/client/api/FormApi.java

@@ -88,6 +88,54 @@ public class FormApi {
     return operationId + " call failed with: " + statusCode + " - " + body;
   }
 
+  /**
+   * Download file from the given response.
+   *
+   * @param response Response
+   * @return File
+   * @throws ApiException If fail to read file content from response and write to disk
+   */
+  public File downloadFileFromResponse(HttpResponse<InputStream> response) throws ApiException {
+    try {
+      File file = prepareDownloadFile(response);
+      java.nio.file.Files.copy(response.body(), file.toPath(), java.nio.file.StandardCopyOption.REPLACE_EXISTING);
+      return file;
+    } catch (IOException e) {
+      throw new ApiException(e);
+    }
+  }
+
+  /**
+   * <p>Prepare the file for download from the response.</p>
+   *
+   * @param response a {@link java.net.http.HttpResponse} object.
+   * @return a {@link java.io.File} object.
+   * @throws java.io.IOException if any.
+   */
+  private File prepareDownloadFile(HttpResponse<InputStream> response) throws IOException {
+    String filename = null;
+    java.util.Optional<String> contentDisposition = response.headers().firstValue("Content-Disposition");
+    if (contentDisposition.isPresent() && !"".equals(contentDisposition.get())) {
+      // Get filename from the Content-Disposition header.
+      java.util.regex.Pattern pattern = java.util.regex.Pattern.compile("filename=['\"]?([^'\"\\s]+)['\"]?");
+      java.util.regex.Matcher matcher = pattern.matcher(contentDisposition.get());
+      if (matcher.find())
+        filename = matcher.group(1);
+    }
+    File file = null;
+    if (filename != null) {
+      java.nio.file.Path tempDir = java.nio.file.Files.createTempDirectory("swagger-gen-native");
+      java.nio.file.Path filePath = java.nio.file.Files.createFile(tempDir.resolve(filename));
+      file = filePath.toFile();
+      tempDir.toFile().deleteOnExit();   // best effort cleanup
+      file.deleteOnExit(); // best effort cleanup
+    } else {
+      file = java.nio.file.Files.createTempFile("download-", "").toFile();
+      file.deleteOnExit(); // best effort cleanup
+    }
+    return file;
+  }
+
   /**
    * Test form parameter(s)
    * Test form parameter(s)

samples/client/echo_api/java/native/src/main/java/org/openapitools/client/api/HeaderApi.java

@@ -88,6 +88,54 @@ public class HeaderApi {
     return operationId + " call failed with: " + statusCode + " - " + body;
   }
 
+  /**
+   * Download file from the given response.
+   *
+   * @param response Response
+   * @return File
+   * @throws ApiException If fail to read file content from response and write to disk
+   */
+  public File downloadFileFromResponse(HttpResponse<InputStream> response) throws ApiException {
+    try {
+      File file = prepareDownloadFile(response);
+      java.nio.file.Files.copy(response.body(), file.toPath(), java.nio.file.StandardCopyOption.REPLACE_EXISTING);
+      return file;
+    } catch (IOException e) {
+      throw new ApiException(e);
+    }
+  }
+
+  /**
+   * <p>Prepare the file for download from the response.</p>
+   *
+   * @param response a {@link java.net.http.HttpResponse} object.
+   * @return a {@link java.io.File} object.
+   * @throws java.io.IOException if any.
+   */
+  private File prepareDownloadFile(HttpResponse<InputStream> response) throws IOException {
+    String filename = null;
+    java.util.Optional<String> contentDisposition = response.headers().firstValue("Content-Disposition");
+    if (contentDisposition.isPresent() && !"".equals(contentDisposition.get())) {
+      // Get filename from the Content-Disposition header.
+      java.util.regex.Pattern pattern = java.util.regex.Pattern.compile("filename=['\"]?([^'\"\\s]+)['\"]?");
+      java.util.regex.Matcher matcher = pattern.matcher(contentDisposition.get());
+      if (matcher.find())
+        filename = matcher.group(1);
+    }
+    File file = null;
+    if (filename != null) {
+      java.nio.file.Path tempDir = java.nio.file.Files.createTempDirectory("swagger-gen-native");
+      java.nio.file.Path filePath = java.nio.file.Files.createFile(tempDir.resolve(filename));
+      file = filePath.toFile();
+      tempDir.toFile().deleteOnExit();   // best effort cleanup
+      file.deleteOnExit(); // best effort cleanup
+    } else {
+      file = java.nio.file.Files.createTempFile("download-", "").toFile();
+      file.deleteOnExit(); // best effort cleanup
+    }
+    return file;
+  }
+
   /**
    * Test header parameter(s)
    * Test header parameter(s)

samples/client/echo_api/java/native/src/main/java/org/openapitools/client/api/PathApi.java

@@ -88,6 +88,54 @@ public class PathApi {
     return operationId + " call failed with: " + statusCode + " - " + body;
   }
 
+  /**
+   * Download file from the given response.
+   *
+   * @param response Response
+   * @return File
+   * @throws ApiException If fail to read file content from response and write to disk
+   */
+  public File downloadFileFromResponse(HttpResponse<InputStream> response) throws ApiException {
+    try {
+      File file = prepareDownloadFile(response);
+      java.nio.file.Files.copy(response.body(), file.toPath(), java.nio.file.StandardCopyOption.REPLACE_EXISTING);
+      return file;
+    } catch (IOException e) {
+      throw new ApiException(e);
+    }
+  }
+
+  /**
+   * <p>Prepare the file for download from the response.</p>
+   *
+   * @param response a {@link java.net.http.HttpResponse} object.
+   * @return a {@link java.io.File} object.
+   * @throws java.io.IOException if any.
+   */
+  private File prepareDownloadFile(HttpResponse<InputStream> response) throws IOException {
+    String filename = null;
+    java.util.Optional<String> contentDisposition = response.headers().firstValue("Content-Disposition");
+    if (contentDisposition.isPresent() && !"".equals(contentDisposition.get())) {
+      // Get filename from the Content-Disposition header.
+      java.util.regex.Pattern pattern = java.util.regex.Pattern.compile("filename=['\"]?([^'\"\\s]+)['\"]?");
+      java.util.regex.Matcher matcher = pattern.matcher(contentDisposition.get());
+      if (matcher.find())
+        filename = matcher.group(1);
+    }
+    File file = null;
+    if (filename != null) {
+      java.nio.file.Path tempDir = java.nio.file.Files.createTempDirectory("swagger-gen-native");
+      java.nio.file.Path filePath = java.nio.file.Files.createFile(tempDir.resolve(filename));
+      file = filePath.toFile();
+      tempDir.toFile().deleteOnExit();   // best effort cleanup
+      file.deleteOnExit(); // best effort cleanup
+    } else {
+      file = java.nio.file.Files.createTempFile("download-", "").toFile();
+      file.deleteOnExit(); // best effort cleanup
+    }
+    return file;
+  }
+
   /**
    * Test path parameter(s)
    * Test path parameter(s)

samples/client/echo_api/java/native/src/main/java/org/openapitools/client/api/QueryApi.java

@@ -94,6 +94,54 @@ public class QueryApi {
     return operationId + " call failed with: " + statusCode + " - " + body;
   }
 
+  /**
+   * Download file from the given response.
+   *
+   * @param response Response
+   * @return File
+   * @throws ApiException If fail to read file content from response and write to disk
+   */
+  public File downloadFileFromResponse(HttpResponse<InputStream> response) throws ApiException {
+    try {
+      File file = prepareDownloadFile(response);
+      java.nio.file.Files.copy(response.body(), file.toPath(), java.nio.file.StandardCopyOption.REPLACE_EXISTING);
+      return file;
+    } catch (IOException e) {
+      throw new ApiException(e);
+    }
+  }
+
+  /**
+   * <p>Prepare the file for download from the response.</p>
+   *
+   * @param response a {@link java.net.http.HttpResponse} object.
+   * @return a {@link java.io.File} object.
+   * @throws java.io.IOException if any.
+   */
+  private File prepareDownloadFile(HttpResponse<InputStream> response) throws IOException {
+    String filename = null;
+    java.util.Optional<String> contentDisposition = response.headers().firstValue("Content-Disposition");
+    if (contentDisposition.isPresent() && !"".equals(contentDisposition.get())) {
+      // Get filename from the Content-Disposition header.
+      java.util.regex.Pattern pattern = java.util.regex.Pattern.compile("filename=['\"]?([^'\"\\s]+)['\"]?");
+      java.util.regex.Matcher matcher = pattern.matcher(contentDisposition.get());
+      if (matcher.find())
+        filename = matcher.group(1);
+    }
+    File file = null;
+    if (filename != null) {
+      java.nio.file.Path tempDir = java.nio.file.Files.createTempDirectory("swagger-gen-native");
+      java.nio.file.Path filePath = java.nio.file.Files.createFile(tempDir.resolve(filename));
+      file = filePath.toFile();
+      tempDir.toFile().deleteOnExit();   // best effort cleanup
+      file.deleteOnExit(); // best effort cleanup
+    } else {
+      file = java.nio.file.Files.createTempFile("download-", "").toFile();
+      file.deleteOnExit(); // best effort cleanup
+    }
+    return file;
+  }
+
   /**
    * Test query parameter(s)
    * Test query parameter(s)

samples/client/petstore/java/native-async/src/main/java/org/openapitools/client/api/AnotherFakeApi.java

@@ -83,6 +83,54 @@ public class AnotherFakeApi {
     return operationId + " call failed with: " + statusCode + " - " + body;
   }
 
+  /**
+   * Download file from the given response.
+   *
+   * @param response Response
+   * @return File
+   * @throws ApiException If fail to read file content from response and write to disk
+   */
+  public File downloadFileFromResponse(HttpResponse<InputStream> response) throws ApiException {
+    try {
+      File file = prepareDownloadFile(response);
+      java.nio.file.Files.copy(response.body(), file.toPath(), java.nio.file.StandardCopyOption.REPLACE_EXISTING);
+      return file;
+    } catch (IOException e) {
+      throw new ApiException(e);
+    }
+  }
+
+  /**
+   * <p>Prepare the file for download from the response.</p>
+   *
+   * @param response a {@link java.net.http.HttpResponse} object.
+   * @return a {@link java.io.File} object.
+   * @throws java.io.IOException if any.
+   */
+  private File prepareDownloadFile(HttpResponse<InputStream> response) throws IOException {
+    String filename = null;
+    java.util.Optional<String> contentDisposition = response.headers().firstValue("Content-Disposition");
+    if (contentDisposition.isPresent() && !"".equals(contentDisposition.get())) {
+      // Get filename from the Content-Disposition header.
+      java.util.regex.Pattern pattern = java.util.regex.Pattern.compile("filename=['\"]?([^'\"\\s]+)['\"]?");
+      java.util.regex.Matcher matcher = pattern.matcher(contentDisposition.get());
+      if (matcher.find())
+        filename = matcher.group(1);
+    }
+    File file = null;
+    if (filename != null) {
+      java.nio.file.Path tempDir = java.nio.file.Files.createTempDirectory("swagger-gen-native");
+      java.nio.file.Path filePath = java.nio.file.Files.createFile(tempDir.resolve(filename));
+      file = filePath.toFile();
+      tempDir.toFile().deleteOnExit();   // best effort cleanup
+      file.deleteOnExit(); // best effort cleanup
+    } else {
+      file = java.nio.file.Files.createTempFile("download-", "").toFile();
+      file.deleteOnExit(); // best effort cleanup
+    }
+    return file;
+  }
+
   /**
    * To test special tags
    * To test special tags and operation ID starting with number

samples/client/petstore/java/native-async/src/main/java/org/openapitools/client/api/DefaultApi.java

@@ -83,6 +83,54 @@ public class DefaultApi {
     return operationId + " call failed with: " + statusCode + " - " + body;
   }
 
+  /**
+   * Download file from the given response.
+   *
+   * @param response Response
+   * @return File
+   * @throws ApiException If fail to read file content from response and write to disk
+   */
+  public File downloadFileFromResponse(HttpResponse<InputStream> response) throws ApiException {
+    try {
+      File file = prepareDownloadFile(response);
+      java.nio.file.Files.copy(response.body(), file.toPath(), java.nio.file.StandardCopyOption.REPLACE_EXISTING);
+      return file;
+    } catch (IOException e) {
+      throw new ApiException(e);
+    }
+  }
+
+  /**
+   * <p>Prepare the file for download from the response.</p>
+   *
+   * @param response a {@link java.net.http.HttpResponse} object.
+   * @return a {@link java.io.File} object.
+   * @throws java.io.IOException if any.
+   */
+  private File prepareDownloadFile(HttpResponse<InputStream> response) throws IOException {
+    String filename = null;
+    java.util.Optional<String> contentDisposition = response.headers().firstValue("Content-Disposition");
+    if (contentDisposition.isPresent() && !"".equals(contentDisposition.get())) {
+      // Get filename from the Content-Disposition header.
+      java.util.regex.Pattern pattern = java.util.regex.Pattern.compile("filename=['\"]?([^'\"\\s]+)['\"]?");
+      java.util.regex.Matcher matcher = pattern.matcher(contentDisposition.get());
+      if (matcher.find())
+        filename = matcher.group(1);
+    }
+    File file = null;
+    if (filename != null) {
+      java.nio.file.Path tempDir = java.nio.file.Files.createTempDirectory("swagger-gen-native");
+      java.nio.file.Path filePath = java.nio.file.Files.createFile(tempDir.resolve(filename));
+      file = filePath.toFile();
+      tempDir.toFile().deleteOnExit();   // best effort cleanup
+      file.deleteOnExit(); // best effort cleanup
+    } else {
+      file = java.nio.file.Files.createTempFile("download-", "").toFile();
+      file.deleteOnExit(); // best effort cleanup
+    }
+    return file;
+  }
+
   /**
    * 
    * 

samples/client/petstore/java/native-async/src/main/java/org/openapitools/client/api/FakeApi.java

@@ -100,6 +100,54 @@ public class FakeApi {
     return operationId + " call failed with: " + statusCode + " - " + body;
   }
 
+  /**
+   * Download file from the given response.
+   *
+   * @param response Response
+   * @return File
+   * @throws ApiException If fail to read file content from response and write to disk
+   */
+  public File downloadFileFromResponse(HttpResponse<InputStream> response) throws ApiException {
+    try {
+      File file = prepareDownloadFile(response);
+      java.nio.file.Files.copy(response.body(), file.toPath(), java.nio.file.StandardCopyOption.REPLACE_EXISTING);
+      return file;
+    } catch (IOException e) {
+      throw new ApiException(e);
+    }
+  }
+
+  /**
+   * <p>Prepare the file for download from the response.</p>
+   *
+   * @param response a {@link java.net.http.HttpResponse} object.
+   * @return a {@link java.io.File} object.
+   * @throws java.io.IOException if any.
+   */
+  private File prepareDownloadFile(HttpResponse<InputStream> response) throws IOException {
+    String filename = null;
+    java.util.Optional<String> contentDisposition = response.headers().firstValue("Content-Disposition");
+    if (contentDisposition.isPresent() && !"".equals(contentDisposition.get())) {
+      // Get filename from the Content-Disposition header.
+      java.util.regex.Pattern pattern = java.util.regex.Pattern.compile("filename=['\"]?([^'\"\\s]+)['\"]?");
+      java.util.regex.Matcher matcher = pattern.matcher(contentDisposition.get());
+      if (matcher.find())
+        filename = matcher.group(1);
+    }
+    File file = null;
+    if (filename != null) {
+      java.nio.file.Path tempDir = java.nio.file.Files.createTempDirectory("swagger-gen-native");
+      java.nio.file.Path filePath = java.nio.file.Files.createFile(tempDir.resolve(filename));
+      file = filePath.toFile();
+      tempDir.toFile().deleteOnExit();   // best effort cleanup
+      file.deleteOnExit(); // best effort cleanup
+    } else {
+      file = java.nio.file.Files.createTempFile("download-", "").toFile();
+      file.deleteOnExit(); // best effort cleanup
+    }
+    return file;
+  }
+
   /**
    * 
    * for Java apache and Java native, test toUrlQueryString for maps with BegDecimal keys

samples/client/petstore/java/native-async/src/main/java/org/openapitools/client/api/FakeClassnameTags123Api.java

@@ -89,6 +89,54 @@ public class FakeClassnameTags123Api {
     return operationId + " call failed with: " + statusCode + " - " + body;
   }
 
+  /**
+   * Download file from the given response.
+   *
+   * @param response Response
+   * @return File
+   * @throws ApiException If fail to read file content from response and write to disk
+   */
+  public File downloadFileFromResponse(HttpResponse<InputStream> response) throws ApiException {
+    try {
+      File file = prepareDownloadFile(response);
+      java.nio.file.Files.copy(response.body(), file.toPath(), java.nio.file.StandardCopyOption.REPLACE_EXISTING);
+      return file;
+    } catch (IOException e) {
+      throw new ApiException(e);
+    }
+  }
+
+  /**
+   * <p>Prepare the file for download from the response.</p>
+   *
+   * @param response a {@link java.net.http.HttpResponse} object.
+   * @return a {@link java.io.File} object.
+   * @throws java.io.IOException if any.
+   */
+  private File prepareDownloadFile(HttpResponse<InputStream> response) throws IOException {
+    String filename = null;
+    java.util.Optional<String> contentDisposition = response.headers().firstValue("Content-Disposition");
+    if (contentDisposition.isPresent() && !"".equals(contentDisposition.get())) {
+      // Get filename from the Content-Disposition header.
+      java.util.regex.Pattern pattern = java.util.regex.Pattern.compile("filename=['\"]?([^'\"\\s]+)['\"]?");
+      java.util.regex.Matcher matcher = pattern.matcher(contentDisposition.get());
+      if (matcher.find())
+        filename = matcher.group(1);
+    }
+    File file = null;
+    if (filename != null) {
+      java.nio.file.Path tempDir = java.nio.file.Files.createTempDirectory("swagger-gen-native");
+      java.nio.file.Path filePath = java.nio.file.Files.createFile(tempDir.resolve(filename));
+      file = filePath.toFile();
+      tempDir.toFile().deleteOnExit();   // best effort cleanup
+      file.deleteOnExit(); // best effort cleanup
+    } else {
+      file = java.nio.file.Files.createTempFile("download-", "").toFile();
+      file.deleteOnExit(); // best effort cleanup
+    }
+    return file;
+  }
+
   /**
    * To test class name in snake case
    * To test class name in snake case

samples/client/petstore/java/native-async/src/main/java/org/openapitools/client/api/PetApi.java

@@ -91,6 +91,54 @@ public class PetApi {
     return operationId + " call failed with: " + statusCode + " - " + body;
   }
 
+  /**
+   * Download file from the given response.
+   *
+   * @param response Response
+   * @return File
+   * @throws ApiException If fail to read file content from response and write to disk
+   */
+  public File downloadFileFromResponse(HttpResponse<InputStream> response) throws ApiException {
+    try {
+      File file = prepareDownloadFile(response);
+      java.nio.file.Files.copy(response.body(), file.toPath(), java.nio.file.StandardCopyOption.REPLACE_EXISTING);
+      return file;
+    } catch (IOException e) {
+      throw new ApiException(e);
+    }
+  }
+
+  /**
+   * <p>Prepare the file for download from the response.</p>
+   *
+   * @param response a {@link java.net.http.HttpResponse} object.
+   * @return a {@link java.io.File} object.
+   * @throws java.io.IOException if any.
+   */
+  private File prepareDownloadFile(HttpResponse<InputStream> response) throws IOException {
+    String filename = null;
+    java.util.Optional<String> contentDisposition = response.headers().firstValue("Content-Disposition");
+    if (contentDisposition.isPresent() && !"".equals(contentDisposition.get())) {
+      // Get filename from the Content-Disposition header.
+      java.util.regex.Pattern pattern = java.util.regex.Pattern.compile("filename=['\"]?([^'\"\\s]+)['\"]?");
+      java.util.regex.Matcher matcher = pattern.matcher(contentDisposition.get());
+      if (matcher.find())
+        filename = matcher.group(1);
+    }
+    File file = null;
+    if (filename != null) {
+      java.nio.file.Path tempDir = java.nio.file.Files.createTempDirectory("swagger-gen-native");
+      java.nio.file.Path filePath = java.nio.file.Files.createFile(tempDir.resolve(filename));
+      file = filePath.toFile();
+      tempDir.toFile().deleteOnExit();   // best effort cleanup
+      file.deleteOnExit(); // best effort cleanup
+    } else {
+      file = java.nio.file.Files.createTempFile("download-", "").toFile();
+      file.deleteOnExit(); // best effort cleanup
+    }
+    return file;
+  }
+
   /**
    * Add a new pet to the store
    * 

samples/client/petstore/java/native-async/src/main/java/org/openapitools/client/api/StoreApi.java

@@ -89,6 +89,54 @@ public class StoreApi {
     return operationId + " call failed with: " + statusCode + " - " + body;
   }
 
+  /**
+   * Download file from the given response.
+   *
+   * @param response Response
+   * @return File
+   * @throws ApiException If fail to read file content from response and write to disk
+   */
+  public File downloadFileFromResponse(HttpResponse<InputStream> response) throws ApiException {
+    try {
+      File file = prepareDownloadFile(response);
+      java.nio.file.Files.copy(response.body(), file.toPath(), java.nio.file.StandardCopyOption.REPLACE_EXISTING);
+      return file;
+    } catch (IOException e) {
+      throw new ApiException(e);
+    }
+  }
+
+  /**
+   * <p>Prepare the file for download from the response.</p>
+   *
+   * @param response a {@link java.net.http.HttpResponse} object.
+   * @return a {@link java.io.File} object.
+   * @throws java.io.IOException if any.
+   */
+  private File prepareDownloadFile(HttpResponse<InputStream> response) throws IOException {
+    String filename = null;
+    java.util.Optional<String> contentDisposition = response.headers().firstValue("Content-Disposition");
+    if (contentDisposition.isPresent() && !"".equals(contentDisposition.get())) {
+      // Get filename from the Content-Disposition header.
+      java.util.regex.Pattern pattern = java.util.regex.Pattern.compile("filename=['\"]?([^'\"\\s]+)['\"]?");
+      java.util.regex.Matcher matcher = pattern.matcher(contentDisposition.get());
+      if (matcher.find())
+        filename = matcher.group(1);
+    }
+    File file = null;
+    if (filename != null) {
+      java.nio.file.Path tempDir = java.nio.file.Files.createTempDirectory("swagger-gen-native");
+      java.nio.file.Path filePath = java.nio.file.Files.createFile(tempDir.resolve(filename));
+      file = filePath.toFile();
+      tempDir.toFile().deleteOnExit();   // best effort cleanup
+      file.deleteOnExit(); // best effort cleanup
+    } else {
+      file = java.nio.file.Files.createTempFile("download-", "").toFile();
+      file.deleteOnExit(); // best effort cleanup
+    }
+    return file;
+  }
+
   /**
    * Delete purchase order by ID
    * For valid response try integer IDs with value &lt; 1000. Anything above 1000 or nonintegers will generate API errors

samples/client/petstore/java/native-async/src/main/java/org/openapitools/client/api/UserApi.java

@@ -90,6 +90,54 @@ public class UserApi {
     return operationId + " call failed with: " + statusCode + " - " + body;
   }
 
+  /**
+   * Download file from the given response.
+   *
+   * @param response Response
+   * @return File
+   * @throws ApiException If fail to read file content from response and write to disk
+   */
+  public File downloadFileFromResponse(HttpResponse<InputStream> response) throws ApiException {
+    try {
+      File file = prepareDownloadFile(response);
+      java.nio.file.Files.copy(response.body(), file.toPath(), java.nio.file.StandardCopyOption.REPLACE_EXISTING);
+      return file;
+    } catch (IOException e) {
+      throw new ApiException(e);
+    }
+  }
+
+  /**
+   * <p>Prepare the file for download from the response.</p>
+   *
+   * @param response a {@link java.net.http.HttpResponse} object.
+   * @return a {@link java.io.File} object.
+   * @throws java.io.IOException if any.
+   */
+  private File prepareDownloadFile(HttpResponse<InputStream> response) throws IOException {
+    String filename = null;
+    java.util.Optional<String> contentDisposition = response.headers().firstValue("Content-Disposition");
+    if (contentDisposition.isPresent() && !"".equals(contentDisposition.get())) {
+      // Get filename from the Content-Disposition header.
+      java.util.regex.Pattern pattern = java.util.regex.Pattern.compile("filename=['\"]?([^'\"\\s]+)['\"]?");
+      java.util.regex.Matcher matcher = pattern.matcher(contentDisposition.get());
+      if (matcher.find())
+        filename = matcher.group(1);
+    }
+    File file = null;
+    if (filename != null) {
+      java.nio.file.Path tempDir = java.nio.file.Files.createTempDirectory("swagger-gen-native");
+      java.nio.file.Path filePath = java.nio.file.Files.createFile(tempDir.resolve(filename));
+      file = filePath.toFile();
+      tempDir.toFile().deleteOnExit();   // best effort cleanup
+      file.deleteOnExit(); // best effort cleanup
+    } else {
+      file = java.nio.file.Files.createTempFile("download-", "").toFile();
+      file.deleteOnExit(); // best effort cleanup
+    }
+    return file;
+  }
+
   /**
    * Create user
    * This can only be done by the logged in user.

samples/client/petstore/java/native-jakarta/src/main/java/org/openapitools/client/api/PetApi.java

@@ -90,6 +90,54 @@ public class PetApi {
     return operationId + " call failed with: " + statusCode + " - " + body;
   }
 
+  /**
+   * Download file from the given response.
+   *
+   * @param response Response
+   * @return File
+   * @throws ApiException If fail to read file content from response and write to disk
+   */
+  public File downloadFileFromResponse(HttpResponse<InputStream> response) throws ApiException {
+    try {
+      File file = prepareDownloadFile(response);
+      java.nio.file.Files.copy(response.body(), file.toPath(), java.nio.file.StandardCopyOption.REPLACE_EXISTING);
+      return file;
+    } catch (IOException e) {
+      throw new ApiException(e);
+    }
+  }
+
+  /**
+   * <p>Prepare the file for download from the response.</p>
+   *
+   * @param response a {@link java.net.http.HttpResponse} object.
+   * @return a {@link java.io.File} object.
+   * @throws java.io.IOException if any.
+   */
+  private File prepareDownloadFile(HttpResponse<InputStream> response) throws IOException {
+    String filename = null;
+    java.util.Optional<String> contentDisposition = response.headers().firstValue("Content-Disposition");
+    if (contentDisposition.isPresent() && !"".equals(contentDisposition.get())) {
+      // Get filename from the Content-Disposition header.
+      java.util.regex.Pattern pattern = java.util.regex.Pattern.compile("filename=['\"]?([^'\"\\s]+)['\"]?");
+      java.util.regex.Matcher matcher = pattern.matcher(contentDisposition.get());
+      if (matcher.find())
+        filename = matcher.group(1);
+    }
+    File file = null;
+    if (filename != null) {
+      java.nio.file.Path tempDir = java.nio.file.Files.createTempDirectory("swagger-gen-native");
+      java.nio.file.Path filePath = java.nio.file.Files.createFile(tempDir.resolve(filename));
+      file = filePath.toFile();
+      tempDir.toFile().deleteOnExit();   // best effort cleanup
+      file.deleteOnExit(); // best effort cleanup
+    } else {
+      file = java.nio.file.Files.createTempFile("download-", "").toFile();
+      file.deleteOnExit(); // best effort cleanup
+    }
+    return file;
+  }
+
   /**
    * Add a new pet to the store
    * 
@@ -130,13 +178,17 @@ public class PetApi {
           );
         }
 
+        
+        
         String responseBody = new String(localVarResponse.body().readAllBytes());
+        Pet responseValue = responseBody.isBlank()? null: memberVarObjectMapper.readValue(responseBody, new TypeReference<Pet>() {});
+        
         localVarResponse.body().close();
 
         return new ApiResponse<Pet>(
             localVarResponse.statusCode(),
             localVarResponse.headers().map(),
-            responseBody.isBlank()? null: memberVarObjectMapper.readValue(responseBody, new TypeReference<Pet>() {})
+            responseValue
         );
       } finally {
       }
@@ -300,13 +352,17 @@ public class PetApi {
           );
         }
 
+        
+        
         String responseBody = new String(localVarResponse.body().readAllBytes());
+        List<Pet> responseValue = responseBody.isBlank()? null: memberVarObjectMapper.readValue(responseBody, new TypeReference<List<Pet>>() {});
+        
         localVarResponse.body().close();
 
         return new ApiResponse<List<Pet>>(
             localVarResponse.statusCode(),
             localVarResponse.headers().map(),
-            responseBody.isBlank()? null: memberVarObjectMapper.readValue(responseBody, new TypeReference<List<Pet>>() {})
+            responseValue
         );
       } finally {
       }
@@ -402,13 +458,17 @@ public class PetApi {
           );
         }
 
+        
+        
         String responseBody = new String(localVarResponse.body().readAllBytes());
+        List<Pet> responseValue = responseBody.isBlank()? null: memberVarObjectMapper.readValue(responseBody, new TypeReference<List<Pet>>() {});
+        
         localVarResponse.body().close();
 
         return new ApiResponse<List<Pet>>(
             localVarResponse.statusCode(),
             localVarResponse.headers().map(),
-            responseBody.isBlank()? null: memberVarObjectMapper.readValue(responseBody, new TypeReference<List<Pet>>() {})
+            responseValue
         );
       } finally {
       }
@@ -500,13 +560,17 @@ public class PetApi {
           );
         }
 
+        
+        
         String responseBody = new String(localVarResponse.body().readAllBytes());
+        Pet responseValue = responseBody.isBlank()? null: memberVarObjectMapper.readValue(responseBody, new TypeReference<Pet>() {});
+        
         localVarResponse.body().close();
 
         return new ApiResponse<Pet>(
             localVarResponse.statusCode(),
             localVarResponse.headers().map(),
-            responseBody.isBlank()? null: memberVarObjectMapper.readValue(responseBody, new TypeReference<Pet>() {})
+            responseValue
         );
       } finally {
       }
@@ -588,13 +652,17 @@ public class PetApi {
           );
         }
 
+        
+        
         String responseBody = new String(localVarResponse.body().readAllBytes());
+        Pet responseValue = responseBody.isBlank()? null: memberVarObjectMapper.readValue(responseBody, new TypeReference<Pet>() {});
+        
         localVarResponse.body().close();
 
         return new ApiResponse<Pet>(
             localVarResponse.statusCode(),
             localVarResponse.headers().map(),
-            responseBody.isBlank()? null: memberVarObjectMapper.readValue(responseBody, new TypeReference<Pet>() {})
+            responseValue
         );
       } finally {
       }
@@ -778,13 +846,17 @@ public class PetApi {
           );
         }
 
+        
+        
         String responseBody = new String(localVarResponse.body().readAllBytes());
+        ModelApiResponse responseValue = responseBody.isBlank()? null: memberVarObjectMapper.readValue(responseBody, new TypeReference<ModelApiResponse>() {});
+        
         localVarResponse.body().close();
 
         return new ApiResponse<ModelApiResponse>(
             localVarResponse.statusCode(),
             localVarResponse.headers().map(),
-            responseBody.isBlank()? null: memberVarObjectMapper.readValue(responseBody, new TypeReference<ModelApiResponse>() {})
+            responseValue
         );
       } finally {
       }

samples/client/petstore/java/native-jakarta/src/main/java/org/openapitools/client/api/StoreApi.java

@@ -88,6 +88,54 @@ public class StoreApi {
     return operationId + " call failed with: " + statusCode + " - " + body;
   }
 
+  /**
+   * Download file from the given response.
+   *
+   * @param response Response
+   * @return File
+   * @throws ApiException If fail to read file content from response and write to disk
+   */
+  public File downloadFileFromResponse(HttpResponse<InputStream> response) throws ApiException {
+    try {
+      File file = prepareDownloadFile(response);
+      java.nio.file.Files.copy(response.body(), file.toPath(), java.nio.file.StandardCopyOption.REPLACE_EXISTING);
+      return file;
+    } catch (IOException e) {
+      throw new ApiException(e);
+    }
+  }
+
+  /**
+   * <p>Prepare the file for download from the response.</p>
+   *
+   * @param response a {@link java.net.http.HttpResponse} object.
+   * @return a {@link java.io.File} object.
+   * @throws java.io.IOException if any.
+   */
+  private File prepareDownloadFile(HttpResponse<InputStream> response) throws IOException {
+    String filename = null;
+    java.util.Optional<String> contentDisposition = response.headers().firstValue("Content-Disposition");
+    if (contentDisposition.isPresent() && !"".equals(contentDisposition.get())) {
+      // Get filename from the Content-Disposition header.
+      java.util.regex.Pattern pattern = java.util.regex.Pattern.compile("filename=['\"]?([^'\"\\s]+)['\"]?");
+      java.util.regex.Matcher matcher = pattern.matcher(contentDisposition.get());
+      if (matcher.find())
+        filename = matcher.group(1);
+    }
+    File file = null;
+    if (filename != null) {
+      java.nio.file.Path tempDir = java.nio.file.Files.createTempDirectory("swagger-gen-native");
+      java.nio.file.Path filePath = java.nio.file.Files.createFile(tempDir.resolve(filename));
+      file = filePath.toFile();
+      tempDir.toFile().deleteOnExit();   // best effort cleanup
+      file.deleteOnExit(); // best effort cleanup
+    } else {
+      file = java.nio.file.Files.createTempFile("download-", "").toFile();
+      file.deleteOnExit(); // best effort cleanup
+    }
+    return file;
+  }
+
   /**
    * Delete purchase order by ID
    * For valid response try integer IDs with value &lt; 1000. Anything above 1000 or nonintegers will generate API errors
@@ -202,13 +250,17 @@ public class StoreApi {
           );
         }
 
+        
+        
         String responseBody = new String(localVarResponse.body().readAllBytes());
+        Map<String, Integer> responseValue = responseBody.isBlank()? null: memberVarObjectMapper.readValue(responseBody, new TypeReference<Map<String, Integer>>() {});
+        
         localVarResponse.body().close();
 
         return new ApiResponse<Map<String, Integer>>(
             localVarResponse.statusCode(),
             localVarResponse.headers().map(),
-            responseBody.isBlank()? null: memberVarObjectMapper.readValue(responseBody, new TypeReference<Map<String, Integer>>() {})
+            responseValue
         );
       } finally {
       }
@@ -281,13 +333,17 @@ public class StoreApi {
           );
         }
 
+        
+        
         String responseBody = new String(localVarResponse.body().readAllBytes());
+        Order responseValue = responseBody.isBlank()? null: memberVarObjectMapper.readValue(responseBody, new TypeReference<Order>() {});
+        
         localVarResponse.body().close();
 
         return new ApiResponse<Order>(
             localVarResponse.statusCode(),
             localVarResponse.headers().map(),
-            responseBody.isBlank()? null: memberVarObjectMapper.readValue(responseBody, new TypeReference<Order>() {})
+            responseValue
         );
       } finally {
       }
@@ -365,13 +421,17 @@ public class StoreApi {
           );
         }
 
+        
+        
         String responseBody = new String(localVarResponse.body().readAllBytes());
+        Order responseValue = responseBody.isBlank()? null: memberVarObjectMapper.readValue(responseBody, new TypeReference<Order>() {});
+        
         localVarResponse.body().close();
 
         return new ApiResponse<Order>(
             localVarResponse.statusCode(),
             localVarResponse.headers().map(),
-            responseBody.isBlank()? null: memberVarObjectMapper.readValue(responseBody, new TypeReference<Order>() {})
+            responseValue
         );
       } finally {
       }

samples/client/petstore/java/native-jakarta/src/main/java/org/openapitools/client/api/UserApi.java

@@ -89,6 +89,54 @@ public class UserApi {
     return operationId + " call failed with: " + statusCode + " - " + body;
   }
 
+  /**
+   * Download file from the given response.
+   *
+   * @param response Response
+   * @return File
+   * @throws ApiException If fail to read file content from response and write to disk
+   */
+  public File downloadFileFromResponse(HttpResponse<InputStream> response) throws ApiException {
+    try {
+      File file = prepareDownloadFile(response);
+      java.nio.file.Files.copy(response.body(), file.toPath(), java.nio.file.StandardCopyOption.REPLACE_EXISTING);
+      return file;
+    } catch (IOException e) {
+      throw new ApiException(e);
+    }
+  }
+
+  /**
+   * <p>Prepare the file for download from the response.</p>
+   *
+   * @param response a {@link java.net.http.HttpResponse} object.
+   * @return a {@link java.io.File} object.
+   * @throws java.io.IOException if any.
+   */
+  private File prepareDownloadFile(HttpResponse<InputStream> response) throws IOException {
+    String filename = null;
+    java.util.Optional<String> contentDisposition = response.headers().firstValue("Content-Disposition");
+    if (contentDisposition.isPresent() && !"".equals(contentDisposition.get())) {
+      // Get filename from the Content-Disposition header.
+      java.util.regex.Pattern pattern = java.util.regex.Pattern.compile("filename=['\"]?([^'\"\\s]+)['\"]?");
+      java.util.regex.Matcher matcher = pattern.matcher(contentDisposition.get());
+      if (matcher.find())
+        filename = matcher.group(1);
+    }
+    File file = null;
+    if (filename != null) {
+      java.nio.file.Path tempDir = java.nio.file.Files.createTempDirectory("swagger-gen-native");
+      java.nio.file.Path filePath = java.nio.file.Files.createFile(tempDir.resolve(filename));
+      file = filePath.toFile();
+      tempDir.toFile().deleteOnExit();   // best effort cleanup
+      file.deleteOnExit(); // best effort cleanup
+    } else {
+      file = java.nio.file.Files.createTempFile("download-", "").toFile();
+      file.deleteOnExit(); // best effort cleanup
+    }
+    return file;
+  }
+
   /**
    * Create user
    * This can only be done by the logged in user.
@@ -448,13 +496,17 @@ public class UserApi {
           );
         }
 
+        
+        
         String responseBody = new String(localVarResponse.body().readAllBytes());
+        User responseValue = responseBody.isBlank()? null: memberVarObjectMapper.readValue(responseBody, new TypeReference<User>() {});
+        
         localVarResponse.body().close();
 
         return new ApiResponse<User>(
             localVarResponse.statusCode(),
             localVarResponse.headers().map(),
-            responseBody.isBlank()? null: memberVarObjectMapper.readValue(responseBody, new TypeReference<User>() {})
+            responseValue
         );
       } finally {
       }
@@ -534,13 +586,17 @@ public class UserApi {
           );
         }
 
+        
+        
         String responseBody = new String(localVarResponse.body().readAllBytes());
+        String responseValue = responseBody.isBlank()? null: memberVarObjectMapper.readValue(responseBody, new TypeReference<String>() {});
+        
         localVarResponse.body().close();
 
         return new ApiResponse<String>(
             localVarResponse.statusCode(),
             localVarResponse.headers().map(),
-            responseBody.isBlank()? null: memberVarObjectMapper.readValue(responseBody, new TypeReference<String>() {})
+            responseValue
         );
       } finally {
       }

samples/client/petstore/java/native/src/main/java/org/openapitools/client/api/AnotherFakeApi.java

@@ -82,6 +82,54 @@ public class AnotherFakeApi {
     return operationId + " call failed with: " + statusCode + " - " + body;
   }
 
+  /**
+   * Download file from the given response.
+   *
+   * @param response Response
+   * @return File
+   * @throws ApiException If fail to read file content from response and write to disk
+   */
+  public File downloadFileFromResponse(HttpResponse<InputStream> response) throws ApiException {
+    try {
+      File file = prepareDownloadFile(response);
+      java.nio.file.Files.copy(response.body(), file.toPath(), java.nio.file.StandardCopyOption.REPLACE_EXISTING);
+      return file;
+    } catch (IOException e) {
+      throw new ApiException(e);
+    }
+  }
+
+  /**
+   * <p>Prepare the file for download from the response.</p>
+   *
+   * @param response a {@link java.net.http.HttpResponse} object.
+   * @return a {@link java.io.File} object.
+   * @throws java.io.IOException if any.
+   */
+  private File prepareDownloadFile(HttpResponse<InputStream> response) throws IOException {
+    String filename = null;
+    java.util.Optional<String> contentDisposition = response.headers().firstValue("Content-Disposition");
+    if (contentDisposition.isPresent() && !"".equals(contentDisposition.get())) {
+      // Get filename from the Content-Disposition header.
+      java.util.regex.Pattern pattern = java.util.regex.Pattern.compile("filename=['\"]?([^'\"\\s]+)['\"]?");
+      java.util.regex.Matcher matcher = pattern.matcher(contentDisposition.get());
+      if (matcher.find())
+        filename = matcher.group(1);
+    }
+    File file = null;
+    if (filename != null) {
+      java.nio.file.Path tempDir = java.nio.file.Files.createTempDirectory("swagger-gen-native");
+      java.nio.file.Path filePath = java.nio.file.Files.createFile(tempDir.resolve(filename));
+      file = filePath.toFile();
+      tempDir.toFile().deleteOnExit();   // best effort cleanup
+      file.deleteOnExit(); // best effort cleanup
+    } else {
+      file = java.nio.file.Files.createTempFile("download-", "").toFile();
+      file.deleteOnExit(); // best effort cleanup
+    }
+    return file;
+  }
+
   /**
    * To test special tags
    * To test special tags and operation ID starting with number
@@ -122,13 +170,17 @@ public class AnotherFakeApi {
           );
         }
 
+        
+        
         String responseBody = new String(localVarResponse.body().readAllBytes());
+        Client responseValue = responseBody.isBlank()? null: memberVarObjectMapper.readValue(responseBody, new TypeReference<Client>() {});
+        
         localVarResponse.body().close();
 
         return new ApiResponse<Client>(
             localVarResponse.statusCode(),
             localVarResponse.headers().map(),
-            responseBody.isBlank()? null: memberVarObjectMapper.readValue(responseBody, new TypeReference<Client>() {})
+            responseValue
         );
       } finally {
       }

samples/client/petstore/java/native/src/main/java/org/openapitools/client/api/DefaultApi.java

@@ -82,6 +82,54 @@ public class DefaultApi {
     return operationId + " call failed with: " + statusCode + " - " + body;
   }
 
+  /**
+   * Download file from the given response.
+   *
+   * @param response Response
+   * @return File
+   * @throws ApiException If fail to read file content from response and write to disk
+   */
+  public File downloadFileFromResponse(HttpResponse<InputStream> response) throws ApiException {
+    try {
+      File file = prepareDownloadFile(response);
+      java.nio.file.Files.copy(response.body(), file.toPath(), java.nio.file.StandardCopyOption.REPLACE_EXISTING);
+      return file;
+    } catch (IOException e) {
+      throw new ApiException(e);
+    }
+  }
+
+  /**
+   * <p>Prepare the file for download from the response.</p>
+   *
+   * @param response a {@link java.net.http.HttpResponse} object.
+   * @return a {@link java.io.File} object.
+   * @throws java.io.IOException if any.
+   */
+  private File prepareDownloadFile(HttpResponse<InputStream> response) throws IOException {
+    String filename = null;
+    java.util.Optional<String> contentDisposition = response.headers().firstValue("Content-Disposition");
+    if (contentDisposition.isPresent() && !"".equals(contentDisposition.get())) {
+      // Get filename from the Content-Disposition header.
+      java.util.regex.Pattern pattern = java.util.regex.Pattern.compile("filename=['\"]?([^'\"\\s]+)['\"]?");
+      java.util.regex.Matcher matcher = pattern.matcher(contentDisposition.get());
+      if (matcher.find())
+        filename = matcher.group(1);
+    }
+    File file = null;
+    if (filename != null) {
+      java.nio.file.Path tempDir = java.nio.file.Files.createTempDirectory("swagger-gen-native");
+      java.nio.file.Path filePath = java.nio.file.Files.createFile(tempDir.resolve(filename));
+      file = filePath.toFile();
+      tempDir.toFile().deleteOnExit();   // best effort cleanup
+      file.deleteOnExit(); // best effort cleanup
+    } else {
+      file = java.nio.file.Files.createTempFile("download-", "").toFile();
+      file.deleteOnExit(); // best effort cleanup
+    }
+    return file;
+  }
+
   /**
    * 
    * 
@@ -120,13 +168,17 @@ public class DefaultApi {
           );
         }
 
+        
+        
         String responseBody = new String(localVarResponse.body().readAllBytes());
+        FooGetDefaultResponse responseValue = responseBody.isBlank()? null: memberVarObjectMapper.readValue(responseBody, new TypeReference<FooGetDefaultResponse>() {});
+        
         localVarResponse.body().close();
 
         return new ApiResponse<FooGetDefaultResponse>(
             localVarResponse.statusCode(),
             localVarResponse.headers().map(),
-            responseBody.isBlank()? null: memberVarObjectMapper.readValue(responseBody, new TypeReference<FooGetDefaultResponse>() {})
+            responseValue
         );
       } finally {
       }

samples/client/petstore/java/native/src/main/java/org/openapitools/client/api/FakeApi.java

@@ -99,6 +99,54 @@ public class FakeApi {
     return operationId + " call failed with: " + statusCode + " - " + body;
   }
 
+  /**
+   * Download file from the given response.
+   *
+   * @param response Response
+   * @return File
+   * @throws ApiException If fail to read file content from response and write to disk
+   */
+  public File downloadFileFromResponse(HttpResponse<InputStream> response) throws ApiException {
+    try {
+      File file = prepareDownloadFile(response);
+      java.nio.file.Files.copy(response.body(), file.toPath(), java.nio.file.StandardCopyOption.REPLACE_EXISTING);
+      return file;
+    } catch (IOException e) {
+      throw new ApiException(e);
+    }
+  }
+
+  /**
+   * <p>Prepare the file for download from the response.</p>
+   *
+   * @param response a {@link java.net.http.HttpResponse} object.
+   * @return a {@link java.io.File} object.
+   * @throws java.io.IOException if any.
+   */
+  private File prepareDownloadFile(HttpResponse<InputStream> response) throws IOException {
+    String filename = null;
+    java.util.Optional<String> contentDisposition = response.headers().firstValue("Content-Disposition");
+    if (contentDisposition.isPresent() && !"".equals(contentDisposition.get())) {
+      // Get filename from the Content-Disposition header.
+      java.util.regex.Pattern pattern = java.util.regex.Pattern.compile("filename=['\"]?([^'\"\\s]+)['\"]?");
+      java.util.regex.Matcher matcher = pattern.matcher(contentDisposition.get());
+      if (matcher.find())
+        filename = matcher.group(1);
+    }
+    File file = null;
+    if (filename != null) {
+      java.nio.file.Path tempDir = java.nio.file.Files.createTempDirectory("swagger-gen-native");
+      java.nio.file.Path filePath = java.nio.file.Files.createFile(tempDir.resolve(filename));
+      file = filePath.toFile();
+      tempDir.toFile().deleteOnExit();   // best effort cleanup
+      file.deleteOnExit(); // best effort cleanup
+    } else {
+      file = java.nio.file.Files.createTempFile("download-", "").toFile();
+      file.deleteOnExit(); // best effort cleanup
+    }
+    return file;
+  }
+
   /**
    * 
    * for Java apache and Java native, test toUrlQueryString for maps with BegDecimal keys
@@ -137,13 +185,17 @@ public class FakeApi {
           );
         }
 
+        
+        
         String responseBody = new String(localVarResponse.body().readAllBytes());
+        FakeBigDecimalMap200Response responseValue = responseBody.isBlank()? null: memberVarObjectMapper.readValue(responseBody, new TypeReference<FakeBigDecimalMap200Response>() {});
+        
         localVarResponse.body().close();
 
         return new ApiResponse<FakeBigDecimalMap200Response>(
             localVarResponse.statusCode(),
             localVarResponse.headers().map(),
-            responseBody.isBlank()? null: memberVarObjectMapper.readValue(responseBody, new TypeReference<FakeBigDecimalMap200Response>() {})
+            responseValue
         );
       } finally {
       }
@@ -214,13 +266,17 @@ public class FakeApi {
           );
         }
 
+        
+        
         String responseBody = new String(localVarResponse.body().readAllBytes());
+        HealthCheckResult responseValue = responseBody.isBlank()? null: memberVarObjectMapper.readValue(responseBody, new TypeReference<HealthCheckResult>() {});
+        
         localVarResponse.body().close();
 
         return new ApiResponse<HealthCheckResult>(
             localVarResponse.statusCode(),
             localVarResponse.headers().map(),
-            responseBody.isBlank()? null: memberVarObjectMapper.readValue(responseBody, new TypeReference<HealthCheckResult>() {})
+            responseValue
         );
       } finally {
       }
@@ -293,13 +349,17 @@ public class FakeApi {
           );
         }
 
+        
+        
         String responseBody = new String(localVarResponse.body().readAllBytes());
+        Boolean responseValue = responseBody.isBlank()? null: memberVarObjectMapper.readValue(responseBody, new TypeReference<Boolean>() {});
+        
         localVarResponse.body().close();
 
         return new ApiResponse<Boolean>(
             localVarResponse.statusCode(),
             localVarResponse.headers().map(),
-            responseBody.isBlank()? null: memberVarObjectMapper.readValue(responseBody, new TypeReference<Boolean>() {})
+            responseValue
         );
       } finally {
       }
@@ -378,13 +438,17 @@ public class FakeApi {
           );
         }
 
+        
+        
         String responseBody = new String(localVarResponse.body().readAllBytes());
+        OuterComposite responseValue = responseBody.isBlank()? null: memberVarObjectMapper.readValue(responseBody, new TypeReference<OuterComposite>() {});
+        
         localVarResponse.body().close();
 
         return new ApiResponse<OuterComposite>(
             localVarResponse.statusCode(),
             localVarResponse.headers().map(),
-            responseBody.isBlank()? null: memberVarObjectMapper.readValue(responseBody, new TypeReference<OuterComposite>() {})
+            responseValue
         );
       } finally {
       }
@@ -463,13 +527,17 @@ public class FakeApi {
           );
         }
 
+        
+        
         String responseBody = new String(localVarResponse.body().readAllBytes());
+        BigDecimal responseValue = responseBody.isBlank()? null: memberVarObjectMapper.readValue(responseBody, new TypeReference<BigDecimal>() {});
+        
         localVarResponse.body().close();
 
         return new ApiResponse<BigDecimal>(
             localVarResponse.statusCode(),
             localVarResponse.headers().map(),
-            responseBody.isBlank()? null: memberVarObjectMapper.readValue(responseBody, new TypeReference<BigDecimal>() {})
+            responseValue
         );
       } finally {
       }
@@ -548,13 +616,17 @@ public class FakeApi {
           );
         }
 
+        
+        
         String responseBody = new String(localVarResponse.body().readAllBytes());
+        String responseValue = responseBody.isBlank()? null: memberVarObjectMapper.readValue(responseBody, new TypeReference<String>() {});
+        
         localVarResponse.body().close();
 
         return new ApiResponse<String>(
             localVarResponse.statusCode(),
             localVarResponse.headers().map(),
-            responseBody.isBlank()? null: memberVarObjectMapper.readValue(responseBody, new TypeReference<String>() {})
+            responseValue
         );
       } finally {
       }
@@ -626,13 +698,17 @@ public class FakeApi {
           );
         }
 
+        
+        
         String responseBody = new String(localVarResponse.body().readAllBytes());
+        List<OuterEnum> responseValue = responseBody.isBlank()? null: memberVarObjectMapper.readValue(responseBody, new TypeReference<List<OuterEnum>>() {});
+        
         localVarResponse.body().close();
 
         return new ApiResponse<List<OuterEnum>>(
             localVarResponse.statusCode(),
             localVarResponse.headers().map(),
-            responseBody.isBlank()? null: memberVarObjectMapper.readValue(responseBody, new TypeReference<List<OuterEnum>>() {})
+            responseValue
         );
       } finally {
       }
@@ -703,13 +779,17 @@ public class FakeApi {
           );
         }
 
+        
+        
         String responseBody = new String(localVarResponse.body().readAllBytes());
+        List<OuterEnum> responseValue = responseBody.isBlank()? null: memberVarObjectMapper.readValue(responseBody, new TypeReference<List<OuterEnum>>() {});
+        
         localVarResponse.body().close();
 
         return new ApiResponse<List<OuterEnum>>(
             localVarResponse.statusCode(),
             localVarResponse.headers().map(),
-            responseBody.isBlank()? null: memberVarObjectMapper.readValue(responseBody, new TypeReference<List<OuterEnum>>() {})
+            responseValue
         );
       } finally {
       }
@@ -1046,13 +1126,17 @@ public class FakeApi {
           );
         }
 
+        
+        
         String responseBody = new String(localVarResponse.body().readAllBytes());
+        Client responseValue = responseBody.isBlank()? null: memberVarObjectMapper.readValue(responseBody, new TypeReference<Client>() {});
+        
         localVarResponse.body().close();
 
         return new ApiResponse<Client>(
             localVarResponse.statusCode(),
             localVarResponse.headers().map(),
-            responseBody.isBlank()? null: memberVarObjectMapper.readValue(responseBody, new TypeReference<Client>() {})
+            responseValue
         );
       } finally {
       }

samples/client/petstore/java/native/src/main/java/org/openapitools/client/api/FakeClassnameTags123Api.java

@@ -88,6 +88,54 @@ public class FakeClassnameTags123Api {
     return operationId + " call failed with: " + statusCode + " - " + body;
   }
 
+  /**
+   * Download file from the given response.
+   *
+   * @param response Response
+   * @return File
+   * @throws ApiException If fail to read file content from response and write to disk
+   */
+  public File downloadFileFromResponse(HttpResponse<InputStream> response) throws ApiException {
+    try {
+      File file = prepareDownloadFile(response);
+      java.nio.file.Files.copy(response.body(), file.toPath(), java.nio.file.StandardCopyOption.REPLACE_EXISTING);
+      return file;
+    } catch (IOException e) {
+      throw new ApiException(e);
+    }
+  }
+
+  /**
+   * <p>Prepare the file for download from the response.</p>
+   *
+   * @param response a {@link java.net.http.HttpResponse} object.
+   * @return a {@link java.io.File} object.
+   * @throws java.io.IOException if any.
+   */
+  private File prepareDownloadFile(HttpResponse<InputStream> response) throws IOException {
+    String filename = null;
+    java.util.Optional<String> contentDisposition = response.headers().firstValue("Content-Disposition");
+    if (contentDisposition.isPresent() && !"".equals(contentDisposition.get())) {
+      // Get filename from the Content-Disposition header.
+      java.util.regex.Pattern pattern = java.util.regex.Pattern.compile("filename=['\"]?([^'\"\\s]+)['\"]?");
+      java.util.regex.Matcher matcher = pattern.matcher(contentDisposition.get());
+      if (matcher.find())
+        filename = matcher.group(1);
+    }
+    File file = null;
+    if (filename != null) {
+      java.nio.file.Path tempDir = java.nio.file.Files.createTempDirectory("swagger-gen-native");
+      java.nio.file.Path filePath = java.nio.file.Files.createFile(tempDir.resolve(filename));
+      file = filePath.toFile();
+      tempDir.toFile().deleteOnExit();   // best effort cleanup
+      file.deleteOnExit(); // best effort cleanup
+    } else {
+      file = java.nio.file.Files.createTempFile("download-", "").toFile();
+      file.deleteOnExit(); // best effort cleanup
+    }
+    return file;
+  }
+
   /**
    * To test class name in snake case
    * To test class name in snake case
@@ -128,13 +176,17 @@ public class FakeClassnameTags123Api {
           );
         }
 
+        
+        
         String responseBody = new String(localVarResponse.body().readAllBytes());
+        Client responseValue = responseBody.isBlank()? null: memberVarObjectMapper.readValue(responseBody, new TypeReference<Client>() {});
+        
         localVarResponse.body().close();
 
         return new ApiResponse<Client>(
             localVarResponse.statusCode(),
             localVarResponse.headers().map(),
-            responseBody.isBlank()? null: memberVarObjectMapper.readValue(responseBody, new TypeReference<Client>() {})
+            responseValue
         );
       } finally {
       }

samples/client/petstore/java/native/src/main/java/org/openapitools/client/api/PetApi.java

@@ -90,6 +90,54 @@ public class PetApi {
     return operationId + " call failed with: " + statusCode + " - " + body;
   }
 
+  /**
+   * Download file from the given response.
+   *
+   * @param response Response
+   * @return File
+   * @throws ApiException If fail to read file content from response and write to disk
+   */
+  public File downloadFileFromResponse(HttpResponse<InputStream> response) throws ApiException {
+    try {
+      File file = prepareDownloadFile(response);
+      java.nio.file.Files.copy(response.body(), file.toPath(), java.nio.file.StandardCopyOption.REPLACE_EXISTING);
+      return file;
+    } catch (IOException e) {
+      throw new ApiException(e);
+    }
+  }
+
+  /**
+   * <p>Prepare the file for download from the response.</p>
+   *
+   * @param response a {@link java.net.http.HttpResponse} object.
+   * @return a {@link java.io.File} object.
+   * @throws java.io.IOException if any.
+   */
+  private File prepareDownloadFile(HttpResponse<InputStream> response) throws IOException {
+    String filename = null;
+    java.util.Optional<String> contentDisposition = response.headers().firstValue("Content-Disposition");
+    if (contentDisposition.isPresent() && !"".equals(contentDisposition.get())) {
+      // Get filename from the Content-Disposition header.
+      java.util.regex.Pattern pattern = java.util.regex.Pattern.compile("filename=['\"]?([^'\"\\s]+)['\"]?");
+      java.util.regex.Matcher matcher = pattern.matcher(contentDisposition.get());
+      if (matcher.find())
+        filename = matcher.group(1);
+    }
+    File file = null;
+    if (filename != null) {
+      java.nio.file.Path tempDir = java.nio.file.Files.createTempDirectory("swagger-gen-native");
+      java.nio.file.Path filePath = java.nio.file.Files.createFile(tempDir.resolve(filename));
+      file = filePath.toFile();
+      tempDir.toFile().deleteOnExit();   // best effort cleanup
+      file.deleteOnExit(); // best effort cleanup
+    } else {
+      file = java.nio.file.Files.createTempFile("download-", "").toFile();
+      file.deleteOnExit(); // best effort cleanup
+    }
+    return file;
+  }
+
   /**
    * Add a new pet to the store
    * 
@@ -292,13 +340,17 @@ public class PetApi {
           );
         }
 
+        
+        
         String responseBody = new String(localVarResponse.body().readAllBytes());
+        List<Pet> responseValue = responseBody.isBlank()? null: memberVarObjectMapper.readValue(responseBody, new TypeReference<List<Pet>>() {});
+        
         localVarResponse.body().close();
 
         return new ApiResponse<List<Pet>>(
             localVarResponse.statusCode(),
             localVarResponse.headers().map(),
-            responseBody.isBlank()? null: memberVarObjectMapper.readValue(responseBody, new TypeReference<List<Pet>>() {})
+            responseValue
         );
       } finally {
       }
@@ -394,13 +446,17 @@ public class PetApi {
           );
         }
 
+        
+        
         String responseBody = new String(localVarResponse.body().readAllBytes());
+        List<Pet> responseValue = responseBody.isBlank()? null: memberVarObjectMapper.readValue(responseBody, new TypeReference<List<Pet>>() {});
+        
         localVarResponse.body().close();
 
         return new ApiResponse<List<Pet>>(
             localVarResponse.statusCode(),
             localVarResponse.headers().map(),
-            responseBody.isBlank()? null: memberVarObjectMapper.readValue(responseBody, new TypeReference<List<Pet>>() {})
+            responseValue
         );
       } finally {
       }
@@ -492,13 +548,17 @@ public class PetApi {
           );
         }
 
+        
+        
         String responseBody = new String(localVarResponse.body().readAllBytes());
+        Pet responseValue = responseBody.isBlank()? null: memberVarObjectMapper.readValue(responseBody, new TypeReference<Pet>() {});
+        
         localVarResponse.body().close();
 
         return new ApiResponse<Pet>(
             localVarResponse.statusCode(),
             localVarResponse.headers().map(),
-            responseBody.isBlank()? null: memberVarObjectMapper.readValue(responseBody, new TypeReference<Pet>() {})
+            responseValue
         );
       } finally {
       }
@@ -758,13 +818,17 @@ public class PetApi {
           );
         }
 
+        
+        
         String responseBody = new String(localVarResponse.body().readAllBytes());
+        ModelApiResponse responseValue = responseBody.isBlank()? null: memberVarObjectMapper.readValue(responseBody, new TypeReference<ModelApiResponse>() {});
+        
         localVarResponse.body().close();
 
         return new ApiResponse<ModelApiResponse>(
             localVarResponse.statusCode(),
             localVarResponse.headers().map(),
-            responseBody.isBlank()? null: memberVarObjectMapper.readValue(responseBody, new TypeReference<ModelApiResponse>() {})
+            responseValue
         );
       } finally {
       }
@@ -882,13 +946,17 @@ public class PetApi {
           );
         }
 
+        
+        
         String responseBody = new String(localVarResponse.body().readAllBytes());
+        ModelApiResponse responseValue = responseBody.isBlank()? null: memberVarObjectMapper.readValue(responseBody, new TypeReference<ModelApiResponse>() {});
+        
         localVarResponse.body().close();
 
         return new ApiResponse<ModelApiResponse>(
             localVarResponse.statusCode(),
             localVarResponse.headers().map(),
-            responseBody.isBlank()? null: memberVarObjectMapper.readValue(responseBody, new TypeReference<ModelApiResponse>() {})
+            responseValue
         );
       } finally {
       }

samples/client/petstore/java/native/src/main/java/org/openapitools/client/api/StoreApi.java

@@ -88,6 +88,54 @@ public class StoreApi {
     return operationId + " call failed with: " + statusCode + " - " + body;
   }
 
+  /**
+   * Download file from the given response.
+   *
+   * @param response Response
+   * @return File
+   * @throws ApiException If fail to read file content from response and write to disk
+   */
+  public File downloadFileFromResponse(HttpResponse<InputStream> response) throws ApiException {
+    try {
+      File file = prepareDownloadFile(response);
+      java.nio.file.Files.copy(response.body(), file.toPath(), java.nio.file.StandardCopyOption.REPLACE_EXISTING);
+      return file;
+    } catch (IOException e) {
+      throw new ApiException(e);
+    }
+  }
+
+  /**
+   * <p>Prepare the file for download from the response.</p>
+   *
+   * @param response a {@link java.net.http.HttpResponse} object.
+   * @return a {@link java.io.File} object.
+   * @throws java.io.IOException if any.
+   */
+  private File prepareDownloadFile(HttpResponse<InputStream> response) throws IOException {
+    String filename = null;
+    java.util.Optional<String> contentDisposition = response.headers().firstValue("Content-Disposition");
+    if (contentDisposition.isPresent() && !"".equals(contentDisposition.get())) {
+      // Get filename from the Content-Disposition header.
+      java.util.regex.Pattern pattern = java.util.regex.Pattern.compile("filename=['\"]?([^'\"\\s]+)['\"]?");
+      java.util.regex.Matcher matcher = pattern.matcher(contentDisposition.get());
+      if (matcher.find())
+        filename = matcher.group(1);
+    }
+    File file = null;
+    if (filename != null) {
+      java.nio.file.Path tempDir = java.nio.file.Files.createTempDirectory("swagger-gen-native");
+      java.nio.file.Path filePath = java.nio.file.Files.createFile(tempDir.resolve(filename));
+      file = filePath.toFile();
+      tempDir.toFile().deleteOnExit();   // best effort cleanup
+      file.deleteOnExit(); // best effort cleanup
+    } else {
+      file = java.nio.file.Files.createTempFile("download-", "").toFile();
+      file.deleteOnExit(); // best effort cleanup
+    }
+    return file;
+  }
+
   /**
    * Delete purchase order by ID
    * For valid response try integer IDs with value &lt; 1000. Anything above 1000 or nonintegers will generate API errors
@@ -202,13 +250,17 @@ public class StoreApi {
           );
         }
 
+        
+        
         String responseBody = new String(localVarResponse.body().readAllBytes());
+        Map<String, Integer> responseValue = responseBody.isBlank()? null: memberVarObjectMapper.readValue(responseBody, new TypeReference<Map<String, Integer>>() {});
+        
         localVarResponse.body().close();
 
         return new ApiResponse<Map<String, Integer>>(
             localVarResponse.statusCode(),
             localVarResponse.headers().map(),
-            responseBody.isBlank()? null: memberVarObjectMapper.readValue(responseBody, new TypeReference<Map<String, Integer>>() {})
+            responseValue
         );
       } finally {
       }
@@ -281,13 +333,17 @@ public class StoreApi {
           );
         }
 
+        
+        
         String responseBody = new String(localVarResponse.body().readAllBytes());
+        Order responseValue = responseBody.isBlank()? null: memberVarObjectMapper.readValue(responseBody, new TypeReference<Order>() {});
+        
         localVarResponse.body().close();
 
         return new ApiResponse<Order>(
             localVarResponse.statusCode(),
             localVarResponse.headers().map(),
-            responseBody.isBlank()? null: memberVarObjectMapper.readValue(responseBody, new TypeReference<Order>() {})
+            responseValue
         );
       } finally {
       }
@@ -365,13 +421,17 @@ public class StoreApi {
           );
         }
 
+        
+        
         String responseBody = new String(localVarResponse.body().readAllBytes());
+        Order responseValue = responseBody.isBlank()? null: memberVarObjectMapper.readValue(responseBody, new TypeReference<Order>() {});
+        
         localVarResponse.body().close();
 
         return new ApiResponse<Order>(
             localVarResponse.statusCode(),
             localVarResponse.headers().map(),
-            responseBody.isBlank()? null: memberVarObjectMapper.readValue(responseBody, new TypeReference<Order>() {})
+            responseValue
         );
       } finally {
       }

samples/client/petstore/java/native/src/main/java/org/openapitools/client/api/UserApi.java

@@ -89,6 +89,54 @@ public class UserApi {
     return operationId + " call failed with: " + statusCode + " - " + body;
   }
 
+  /**
+   * Download file from the given response.
+   *
+   * @param response Response
+   * @return File
+   * @throws ApiException If fail to read file content from response and write to disk
+   */
+  public File downloadFileFromResponse(HttpResponse<InputStream> response) throws ApiException {
+    try {
+      File file = prepareDownloadFile(response);
+      java.nio.file.Files.copy(response.body(), file.toPath(), java.nio.file.StandardCopyOption.REPLACE_EXISTING);
+      return file;
+    } catch (IOException e) {
+      throw new ApiException(e);
+    }
+  }
+
+  /**
+   * <p>Prepare the file for download from the response.</p>
+   *
+   * @param response a {@link java.net.http.HttpResponse} object.
+   * @return a {@link java.io.File} object.
+   * @throws java.io.IOException if any.
+   */
+  private File prepareDownloadFile(HttpResponse<InputStream> response) throws IOException {
+    String filename = null;
+    java.util.Optional<String> contentDisposition = response.headers().firstValue("Content-Disposition");
+    if (contentDisposition.isPresent() && !"".equals(contentDisposition.get())) {
+      // Get filename from the Content-Disposition header.
+      java.util.regex.Pattern pattern = java.util.regex.Pattern.compile("filename=['\"]?([^'\"\\s]+)['\"]?");
+      java.util.regex.Matcher matcher = pattern.matcher(contentDisposition.get());
+      if (matcher.find())
+        filename = matcher.group(1);
+    }
+    File file = null;
+    if (filename != null) {
+      java.nio.file.Path tempDir = java.nio.file.Files.createTempDirectory("swagger-gen-native");
+      java.nio.file.Path filePath = java.nio.file.Files.createFile(tempDir.resolve(filename));
+      file = filePath.toFile();
+      tempDir.toFile().deleteOnExit();   // best effort cleanup
+      file.deleteOnExit(); // best effort cleanup
+    } else {
+      file = java.nio.file.Files.createTempFile("download-", "").toFile();
+      file.deleteOnExit(); // best effort cleanup
+    }
+    return file;
+  }
+
   /**
    * Create user
    * This can only be done by the logged in user.
@@ -448,13 +496,17 @@ public class UserApi {
           );
         }
 
+        
+        
         String responseBody = new String(localVarResponse.body().readAllBytes());
+        User responseValue = responseBody.isBlank()? null: memberVarObjectMapper.readValue(responseBody, new TypeReference<User>() {});
+        
         localVarResponse.body().close();
 
         return new ApiResponse<User>(
             localVarResponse.statusCode(),
             localVarResponse.headers().map(),
-            responseBody.isBlank()? null: memberVarObjectMapper.readValue(responseBody, new TypeReference<User>() {})
+            responseValue
         );
       } finally {
       }
@@ -534,13 +586,17 @@ public class UserApi {
           );
         }
 
+        
+        
         String responseBody = new String(localVarResponse.body().readAllBytes());
+        String responseValue = responseBody.isBlank()? null: memberVarObjectMapper.readValue(responseBody, new TypeReference<String>() {});
+        
         localVarResponse.body().close();
 
         return new ApiResponse<String>(
             localVarResponse.statusCode(),
             localVarResponse.headers().map(),
-            responseBody.isBlank()? null: memberVarObjectMapper.readValue(responseBody, new TypeReference<String>() {})
+            responseValue
         );
       } finally {
       }