diff --git a/samples/client/petstore/java/okhttp-gson/src/main/java/io/swagger/client/ApiCallback.java b/samples/client/petstore/java/okhttp-gson/src/main/java/io/swagger/client/ApiCallback.java
index d75713c9a01..fcf2d289fbf 100644
--- a/samples/client/petstore/java/okhttp-gson/src/main/java/io/swagger/client/ApiCallback.java
+++ b/samples/client/petstore/java/okhttp-gson/src/main/java/io/swagger/client/ApiCallback.java
@@ -28,4 +28,22 @@ public interface ApiCallback<T> {
    * @param responseHeaders Headers of the response
    */
   void onSuccess(T result, int statusCode, Map<String, List<String>> responseHeaders);
+
+  /**
+   * This is called when the API upload processing.
+   *
+   * @param bytesWritten bytes Written
+   * @param contentLength content length of request body
+   * @param done write end
+   */
+  void onUploadProgress(long bytesWritten, long contentLength, boolean done);
+
+  /**
+   * This is called when the API downlond processing.
+   *
+   * @param bytesRead bytes Read
+   * @param contentLength content lenngth of the response
+   * @param done Read end
+   */
+  void onDownloadProgress(long bytesRead, long contentLength, boolean done);
 }
diff --git a/samples/client/petstore/java/okhttp-gson/src/main/java/io/swagger/client/ApiClient.java b/samples/client/petstore/java/okhttp-gson/src/main/java/io/swagger/client/ApiClient.java
index 6e4e299ad3a..43df2643cd3 100644
--- a/samples/client/petstore/java/okhttp-gson/src/main/java/io/swagger/client/ApiClient.java
+++ b/samples/client/petstore/java/okhttp-gson/src/main/java/io/swagger/client/ApiClient.java
@@ -143,8 +143,8 @@ public class ApiClient {
 
     // Setup authentications (key: authentication name, value: authentication).
     authentications = new HashMap<String, Authentication>();
-    authentications.put("petstore_auth", new OAuth());
     authentications.put("api_key", new ApiKeyAuth("header", "api_key"));
+    authentications.put("petstore_auth", new OAuth());
     // Prevent the authentications from being modified.
     authentications = Collections.unmodifiableMap(authentications);
   }
@@ -820,7 +820,7 @@ public class ApiClient {
    * @param authNames The authentications to apply
    * @return The HTTP call
    */
-  public Call buildCall(String path, String method, List<Pair> queryParams, Object body, Map<String, String> headerParams, Map<String, Object> formParams, String[] authNames) throws ApiException {
+  public Call buildCall(String path, String method, List<Pair> queryParams, Object body, Map<String, String> headerParams, Map<String, Object> formParams, String[] authNames, ProgressRequestBody.ProgressRequestListener progressRequestListener) throws ApiException {
     updateParamsForAuth(authNames, queryParams, headerParams);
 
     final String url = buildUrl(path, queryParams);
@@ -850,7 +850,15 @@ public class ApiClient {
       reqBody = RequestBody.create(MediaType.parse(contentType), serialize(body, contentType));
     }
 
-    Request request = reqBuilder.method(method, reqBody).build();
+    Request request = null;
+
+    if(progressRequestListener != null) {
+      ProgressRequestBody progressRequestBody = new ProgressRequestBody(reqBody, progressRequestListener);
+      request = reqBuilder.method(method, progressRequestBody).build();
+    } else {
+      request = reqBuilder.method(method, reqBody).build();
+    }
+
     return httpClient.newCall(request);
   }
 
diff --git a/samples/client/petstore/java/okhttp-gson/src/main/java/io/swagger/client/ApiException.java b/samples/client/petstore/java/okhttp-gson/src/main/java/io/swagger/client/ApiException.java
index 0bdd5bd17c6..3df58b0b4d1 100644
--- a/samples/client/petstore/java/okhttp-gson/src/main/java/io/swagger/client/ApiException.java
+++ b/samples/client/petstore/java/okhttp-gson/src/main/java/io/swagger/client/ApiException.java
@@ -3,7 +3,7 @@ package io.swagger.client;
 import java.util.Map;
 import java.util.List;
 
-@javax.annotation.Generated(value = "class io.swagger.codegen.languages.JavaClientCodegen", date = "2015-10-20T11:42:25.339-07:00")
+@javax.annotation.Generated(value = "class io.swagger.codegen.languages.JavaClientCodegen", date = "2015-11-21T19:41:14.431+08:00")
 public class ApiException extends Exception {
   private int code = 0;
   private Map<String, List<String>> responseHeaders = null;
diff --git a/samples/client/petstore/java/okhttp-gson/src/main/java/io/swagger/client/Configuration.java b/samples/client/petstore/java/okhttp-gson/src/main/java/io/swagger/client/Configuration.java
index a63382fc05b..084020d501a 100644
--- a/samples/client/petstore/java/okhttp-gson/src/main/java/io/swagger/client/Configuration.java
+++ b/samples/client/petstore/java/okhttp-gson/src/main/java/io/swagger/client/Configuration.java
@@ -1,6 +1,6 @@
 package io.swagger.client;
 
-@javax.annotation.Generated(value = "class io.swagger.codegen.languages.JavaClientCodegen", date = "2015-10-20T11:42:25.339-07:00")
+@javax.annotation.Generated(value = "class io.swagger.codegen.languages.JavaClientCodegen", date = "2015-11-21T19:41:14.431+08:00")
 public class Configuration {
   private static ApiClient defaultApiClient = new ApiClient();
 
diff --git a/samples/client/petstore/java/okhttp-gson/src/main/java/io/swagger/client/Pair.java b/samples/client/petstore/java/okhttp-gson/src/main/java/io/swagger/client/Pair.java
index 533d318cb5c..91ae60aa14b 100644
--- a/samples/client/petstore/java/okhttp-gson/src/main/java/io/swagger/client/Pair.java
+++ b/samples/client/petstore/java/okhttp-gson/src/main/java/io/swagger/client/Pair.java
@@ -1,6 +1,6 @@
 package io.swagger.client;
 
-@javax.annotation.Generated(value = "class io.swagger.codegen.languages.JavaClientCodegen", date = "2015-10-20T11:42:25.339-07:00")
+@javax.annotation.Generated(value = "class io.swagger.codegen.languages.JavaClientCodegen", date = "2015-11-21T19:41:14.431+08:00")
 public class Pair {
     private String name = "";
     private String value = "";
diff --git a/samples/client/petstore/java/okhttp-gson/src/main/java/io/swagger/client/ProgressRequestBody.java b/samples/client/petstore/java/okhttp-gson/src/main/java/io/swagger/client/ProgressRequestBody.java
new file mode 100644
index 00000000000..71f34ed1140
--- /dev/null
+++ b/samples/client/petstore/java/okhttp-gson/src/main/java/io/swagger/client/ProgressRequestBody.java
@@ -0,0 +1,70 @@
+package io.swagger.client;
+
+import com.squareup.okhttp.MediaType;
+import com.squareup.okhttp.RequestBody;
+
+import java.io.IOException;
+
+import okio.Buffer;
+import okio.BufferedSink;
+import okio.ForwardingSink;
+import okio.Okio;
+import okio.Sink;
+
+public class ProgressRequestBody extends RequestBody {
+
+    public interface ProgressRequestListener {
+        void onRequestProgress(long bytesWritten, long contentLength, boolean done);
+    }
+
+    private final RequestBody requestBody;
+ 
+    private final ProgressRequestListener progressListener;
+  
+    private BufferedSink bufferedSink;
+
+    public ProgressRequestBody(RequestBody requestBody, ProgressRequestListener progressListener) {
+        this.requestBody = requestBody;
+        this.progressListener = progressListener;
+    }
+
+    @Override
+    public MediaType contentType() {
+        return requestBody.contentType();
+    }
+
+    @Override
+    public long contentLength() throws IOException {
+        return requestBody.contentLength();
+    }
+
+    @Override
+    public void writeTo(BufferedSink sink) throws IOException {
+        if (bufferedSink == null) {
+            bufferedSink = Okio.buffer(sink(sink));
+        }
+  
+        requestBody.writeTo(bufferedSink);
+        bufferedSink.flush();
+
+    }
+
+    private Sink sink(Sink sink) {
+        return new ForwardingSink(sink) {
+       
+            long bytesWritten = 0L;
+            long contentLength = 0L;
+
+            @Override
+            public void write(Buffer source, long byteCount) throws IOException {
+                super.write(source, byteCount);
+                if (contentLength == 0) {
+                    contentLength = contentLength();
+                }
+
+                bytesWritten += byteCount;
+                progressListener.onRequestProgress(bytesWritten, contentLength, bytesWritten == contentLength);
+            }
+        };
+    }
+}
diff --git a/samples/client/petstore/java/okhttp-gson/src/main/java/io/swagger/client/ProgressResponseBody.java b/samples/client/petstore/java/okhttp-gson/src/main/java/io/swagger/client/ProgressResponseBody.java
new file mode 100644
index 00000000000..138da3f2106
--- /dev/null
+++ b/samples/client/petstore/java/okhttp-gson/src/main/java/io/swagger/client/ProgressResponseBody.java
@@ -0,0 +1,63 @@
+package io.swagger.client;
+
+import com.squareup.okhttp.MediaType;
+import com.squareup.okhttp.ResponseBody;
+
+import java.io.IOException;
+
+import okio.Buffer;
+import okio.BufferedSource;
+import okio.ForwardingSource;
+import okio.Okio;
+import okio.Source;
+
+public class ProgressResponseBody extends ResponseBody {
+
+    public interface ProgressListener {
+        void update(long bytesRead, long contentLength, boolean done);
+    }
+
+    private final ResponseBody responseBody;
+    private final ProgressListener progressListener;
+    private BufferedSource bufferedSource;
+
+    public ProgressResponseBody(ResponseBody responseBody, ProgressListener progressListener) {
+        this.responseBody = responseBody;
+        this.progressListener = progressListener;
+    }
+
+    @Override
+    public MediaType contentType() {
+        return responseBody.contentType();
+    }
+
+    @Override
+    public long contentLength() throws IOException {
+        return responseBody.contentLength();
+    }
+
+    @Override
+    public BufferedSource source() throws IOException {
+        if (bufferedSource == null) {
+            bufferedSource = Okio.buffer(source(responseBody.source()));
+        }
+        return bufferedSource;
+    }
+
+    private Source source(Source source) {
+        return new ForwardingSource(source) {
+            long totalBytesRead = 0L;
+
+            @Override
+            public long read(Buffer sink, long byteCount) throws IOException {
+                long bytesRead = super.read(sink, byteCount);
+                // read() returns the number of bytes read, or -1 if this source is exhausted.
+                totalBytesRead += bytesRead != -1 ? bytesRead : 0;
+                progressListener.update(totalBytesRead, responseBody.contentLength(), bytesRead == -1);
+                return bytesRead;
+            }
+        };
+    }
+}
+
+
diff --git a/samples/client/petstore/java/okhttp-gson/src/main/java/io/swagger/client/StringUtil.java b/samples/client/petstore/java/okhttp-gson/src/main/java/io/swagger/client/StringUtil.java
index 42d453c31ef..bd4fefc651a 100644
--- a/samples/client/petstore/java/okhttp-gson/src/main/java/io/swagger/client/StringUtil.java
+++ b/samples/client/petstore/java/okhttp-gson/src/main/java/io/swagger/client/StringUtil.java
@@ -1,6 +1,6 @@
 package io.swagger.client;
 
-@javax.annotation.Generated(value = "class io.swagger.codegen.languages.JavaClientCodegen", date = "2015-10-20T11:42:25.339-07:00")
+@javax.annotation.Generated(value = "class io.swagger.codegen.languages.JavaClientCodegen", date = "2015-11-21T19:41:14.431+08:00")
 public class StringUtil {
   /**
    * Check if the given array contains the given value (with case-insensitive comparison).
diff --git a/samples/client/petstore/java/okhttp-gson/src/main/java/io/swagger/client/api/PetApi.java b/samples/client/petstore/java/okhttp-gson/src/main/java/io/swagger/client/api/PetApi.java
index 39154cf855e..d1982566bf9 100644
--- a/samples/client/petstore/java/okhttp-gson/src/main/java/io/swagger/client/api/PetApi.java
+++ b/samples/client/petstore/java/okhttp-gson/src/main/java/io/swagger/client/api/PetApi.java
@@ -5,10 +5,16 @@ import io.swagger.client.ApiClient;
 import io.swagger.client.ApiException;
 import io.swagger.client.Configuration;
 import io.swagger.client.Pair;
+import io.swagger.client.ProgressRequestBody;
+import io.swagger.client.ProgressResponseBody;
 
 import com.google.gson.reflect.TypeToken;
 
 import com.squareup.okhttp.Call;
+import com.squareup.okhttp.Interceptor;
+import com.squareup.okhttp.Response;
+
+import java.io.IOException;
 
 import io.swagger.client.model.Pet;
 import java.io.File;
@@ -37,7 +43,7 @@ public class PetApi {
 
   
   /* Build call for updatePet */
-  private Call updatePetCall(Pet body) throws ApiException {
+  private Call updatePetCall(Pet body, final ProgressResponseBody.ProgressListener progressListener, final ProgressRequestBody.ProgressRequestListener progressRequestListener) throws ApiException {
     Object postBody = body;
     
 
@@ -62,8 +68,20 @@ public class PetApi {
     final String contentType = apiClient.selectHeaderContentType(contentTypes);
     headerParams.put("Content-Type", contentType);
 
+    if(progressListener != null) {
+      apiClient.getHttpClient().networkInterceptors().add(new Interceptor() {
+      @Override
+      public Response intercept(Interceptor.Chain chain) throws IOException {
+        Response originalResponse = chain.proceed(chain.request());
+        return originalResponse.newBuilder()
+                .body(new ProgressResponseBody(originalResponse.body(), progressListener))
+                .build();
+        }
+      });
+    }
+
     String[] authNames = new String[] { "petstore_auth" };
-    return apiClient.buildCall(path, "PUT", queryParams, postBody, headerParams, formParams, authNames);
+    return apiClient.buildCall(path, "PUT", queryParams, postBody, headerParams, formParams, authNames, progressRequestListener);
   }
 
   /**
@@ -72,7 +90,7 @@ public class PetApi {
    * @param body Pet object that needs to be added to the store
    */
   public void updatePet(Pet body) throws ApiException {
-    Call call = updatePetCall(body);
+    Call call = updatePetCall(body, null, null);
     apiClient.execute(call);
   }
 
@@ -83,14 +101,34 @@ public class PetApi {
    * @param callback The callback to be executed when the API call finishes
    * @return The request call
    */
-  public Call updatePetAsync(Pet body, ApiCallback<Void> callback) throws ApiException {
-    Call call = updatePetCall(body);
+  public Call updatePetAsync(Pet body, final ApiCallback<Void> callback) throws ApiException {
+
+    ProgressResponseBody.ProgressListener progressListener = null;
+    ProgressRequestBody.ProgressRequestListener progressRequestListener = null;
+
+    if(callback != null) {
+      progressListener = new ProgressResponseBody.ProgressListener() {
+        @Override
+        public void update(long bytesRead, long contentLength, boolean done) {
+          callback.onDownloadProgress(bytesRead, contentLength, done);
+        } 
+      };
+
+      progressRequestListener = new ProgressRequestBody.ProgressRequestListener() {
+        @Override
+        public void onRequestProgress(long bytesWritten, long contentLength, boolean done) {
+          callback.onUploadProgress(bytesWritten, contentLength, done);
+        }
+      };
+    }
+
+    Call call = updatePetCall(body, progressListener, progressRequestListener);
     apiClient.executeAsync(call, callback);
     return call;
   }
   
   /* Build call for addPet */
-  private Call addPetCall(Pet body) throws ApiException {
+  private Call addPetCall(Pet body, final ProgressResponseBody.ProgressListener progressListener, final ProgressRequestBody.ProgressRequestListener progressRequestListener) throws ApiException {
     Object postBody = body;
     
 
@@ -115,8 +153,20 @@ public class PetApi {
     final String contentType = apiClient.selectHeaderContentType(contentTypes);
     headerParams.put("Content-Type", contentType);
 
+    if(progressListener != null) {
+      apiClient.getHttpClient().networkInterceptors().add(new Interceptor() {
+      @Override
+      public Response intercept(Interceptor.Chain chain) throws IOException {
+        Response originalResponse = chain.proceed(chain.request());
+        return originalResponse.newBuilder()
+                .body(new ProgressResponseBody(originalResponse.body(), progressListener))
+                .build();
+        }
+      });
+    }
+
     String[] authNames = new String[] { "petstore_auth" };
-    return apiClient.buildCall(path, "POST", queryParams, postBody, headerParams, formParams, authNames);
+    return apiClient.buildCall(path, "POST", queryParams, postBody, headerParams, formParams, authNames, progressRequestListener);
   }
 
   /**
@@ -125,7 +175,7 @@ public class PetApi {
    * @param body Pet object that needs to be added to the store
    */
   public void addPet(Pet body) throws ApiException {
-    Call call = addPetCall(body);
+    Call call = addPetCall(body, null, null);
     apiClient.execute(call);
   }
 
@@ -136,14 +186,34 @@ public class PetApi {
    * @param callback The callback to be executed when the API call finishes
    * @return The request call
    */
-  public Call addPetAsync(Pet body, ApiCallback<Void> callback) throws ApiException {
-    Call call = addPetCall(body);
+  public Call addPetAsync(Pet body, final ApiCallback<Void> callback) throws ApiException {
+
+    ProgressResponseBody.ProgressListener progressListener = null;
+    ProgressRequestBody.ProgressRequestListener progressRequestListener = null;
+
+    if(callback != null) {
+      progressListener = new ProgressResponseBody.ProgressListener() {
+        @Override
+        public void update(long bytesRead, long contentLength, boolean done) {
+          callback.onDownloadProgress(bytesRead, contentLength, done);
+        } 
+      };
+
+      progressRequestListener = new ProgressRequestBody.ProgressRequestListener() {
+        @Override
+        public void onRequestProgress(long bytesWritten, long contentLength, boolean done) {
+          callback.onUploadProgress(bytesWritten, contentLength, done);
+        }
+      };
+    }
+
+    Call call = addPetCall(body, progressListener, progressRequestListener);
     apiClient.executeAsync(call, callback);
     return call;
   }
   
   /* Build call for findPetsByStatus */
-  private Call findPetsByStatusCall(List<String> status) throws ApiException {
+  private Call findPetsByStatusCall(List<String> status, final ProgressResponseBody.ProgressListener progressListener, final ProgressRequestBody.ProgressRequestListener progressRequestListener) throws ApiException {
     Object postBody = null;
     
 
@@ -170,8 +240,20 @@ public class PetApi {
     final String contentType = apiClient.selectHeaderContentType(contentTypes);
     headerParams.put("Content-Type", contentType);
 
+    if(progressListener != null) {
+      apiClient.getHttpClient().networkInterceptors().add(new Interceptor() {
+      @Override
+      public Response intercept(Interceptor.Chain chain) throws IOException {
+        Response originalResponse = chain.proceed(chain.request());
+        return originalResponse.newBuilder()
+                .body(new ProgressResponseBody(originalResponse.body(), progressListener))
+                .build();
+        }
+      });
+    }
+
     String[] authNames = new String[] { "petstore_auth" };
-    return apiClient.buildCall(path, "GET", queryParams, postBody, headerParams, formParams, authNames);
+    return apiClient.buildCall(path, "GET", queryParams, postBody, headerParams, formParams, authNames, progressRequestListener);
   }
 
   /**
@@ -181,7 +263,7 @@ public class PetApi {
    * @return List<Pet>
    */
   public List<Pet> findPetsByStatus(List<String> status) throws ApiException {
-    Call call = findPetsByStatusCall(status);
+    Call call = findPetsByStatusCall(status, null, null);
     Type returnType = new TypeToken<List<Pet>>(){}.getType();
     return apiClient.execute(call, returnType);
   }
@@ -193,15 +275,35 @@ public class PetApi {
    * @param callback The callback to be executed when the API call finishes
    * @return The request call
    */
-  public Call findPetsByStatusAsync(List<String> status, ApiCallback<List<Pet>> callback) throws ApiException {
-    Call call = findPetsByStatusCall(status);
+  public Call findPetsByStatusAsync(List<String> status, final ApiCallback<List<Pet>> callback) throws ApiException {
+
+    ProgressResponseBody.ProgressListener progressListener = null;
+    ProgressRequestBody.ProgressRequestListener progressRequestListener = null;
+
+    if(callback != null) {
+      progressListener = new ProgressResponseBody.ProgressListener() {
+        @Override
+        public void update(long bytesRead, long contentLength, boolean done) {
+          callback.onDownloadProgress(bytesRead, contentLength, done);
+        } 
+      };
+
+      progressRequestListener = new ProgressRequestBody.ProgressRequestListener() {
+        @Override
+        public void onRequestProgress(long bytesWritten, long contentLength, boolean done) {
+          callback.onUploadProgress(bytesWritten, contentLength, done);
+        }
+      };
+    }
+
+    Call call = findPetsByStatusCall(status, progressListener, progressRequestListener);
     Type returnType = new TypeToken<List<Pet>>(){}.getType();
     apiClient.executeAsync(call, returnType, callback);
     return call;
   }
   
   /* Build call for findPetsByTags */
-  private Call findPetsByTagsCall(List<String> tags) throws ApiException {
+  private Call findPetsByTagsCall(List<String> tags, final ProgressResponseBody.ProgressListener progressListener, final ProgressRequestBody.ProgressRequestListener progressRequestListener) throws ApiException {
     Object postBody = null;
     
 
@@ -228,8 +330,20 @@ public class PetApi {
     final String contentType = apiClient.selectHeaderContentType(contentTypes);
     headerParams.put("Content-Type", contentType);
 
+    if(progressListener != null) {
+      apiClient.getHttpClient().networkInterceptors().add(new Interceptor() {
+      @Override
+      public Response intercept(Interceptor.Chain chain) throws IOException {
+        Response originalResponse = chain.proceed(chain.request());
+        return originalResponse.newBuilder()
+                .body(new ProgressResponseBody(originalResponse.body(), progressListener))
+                .build();
+        }
+      });
+    }
+
     String[] authNames = new String[] { "petstore_auth" };
-    return apiClient.buildCall(path, "GET", queryParams, postBody, headerParams, formParams, authNames);
+    return apiClient.buildCall(path, "GET", queryParams, postBody, headerParams, formParams, authNames, progressRequestListener);
   }
 
   /**
@@ -239,7 +353,7 @@ public class PetApi {
    * @return List<Pet>
    */
   public List<Pet> findPetsByTags(List<String> tags) throws ApiException {
-    Call call = findPetsByTagsCall(tags);
+    Call call = findPetsByTagsCall(tags, null, null);
     Type returnType = new TypeToken<List<Pet>>(){}.getType();
     return apiClient.execute(call, returnType);
   }
@@ -251,15 +365,35 @@ public class PetApi {
    * @param callback The callback to be executed when the API call finishes
    * @return The request call
    */
-  public Call findPetsByTagsAsync(List<String> tags, ApiCallback<List<Pet>> callback) throws ApiException {
-    Call call = findPetsByTagsCall(tags);
+  public Call findPetsByTagsAsync(List<String> tags, final ApiCallback<List<Pet>> callback) throws ApiException {
+
+    ProgressResponseBody.ProgressListener progressListener = null;
+    ProgressRequestBody.ProgressRequestListener progressRequestListener = null;
+
+    if(callback != null) {
+      progressListener = new ProgressResponseBody.ProgressListener() {
+        @Override
+        public void update(long bytesRead, long contentLength, boolean done) {
+          callback.onDownloadProgress(bytesRead, contentLength, done);
+        } 
+      };
+
+      progressRequestListener = new ProgressRequestBody.ProgressRequestListener() {
+        @Override
+        public void onRequestProgress(long bytesWritten, long contentLength, boolean done) {
+          callback.onUploadProgress(bytesWritten, contentLength, done);
+        }
+      };
+    }
+
+    Call call = findPetsByTagsCall(tags, progressListener, progressRequestListener);
     Type returnType = new TypeToken<List<Pet>>(){}.getType();
     apiClient.executeAsync(call, returnType, callback);
     return call;
   }
   
   /* Build call for getPetById */
-  private Call getPetByIdCall(Long petId) throws ApiException {
+  private Call getPetByIdCall(Long petId, final ProgressResponseBody.ProgressListener progressListener, final ProgressRequestBody.ProgressRequestListener progressRequestListener) throws ApiException {
     Object postBody = null;
     
     // verify the required parameter 'petId' is set
@@ -290,8 +424,20 @@ public class PetApi {
     final String contentType = apiClient.selectHeaderContentType(contentTypes);
     headerParams.put("Content-Type", contentType);
 
+    if(progressListener != null) {
+      apiClient.getHttpClient().networkInterceptors().add(new Interceptor() {
+      @Override
+      public Response intercept(Interceptor.Chain chain) throws IOException {
+        Response originalResponse = chain.proceed(chain.request());
+        return originalResponse.newBuilder()
+                .body(new ProgressResponseBody(originalResponse.body(), progressListener))
+                .build();
+        }
+      });
+    }
+
     String[] authNames = new String[] { "api_key" };
-    return apiClient.buildCall(path, "GET", queryParams, postBody, headerParams, formParams, authNames);
+    return apiClient.buildCall(path, "GET", queryParams, postBody, headerParams, formParams, authNames, progressRequestListener);
   }
 
   /**
@@ -301,7 +447,7 @@ public class PetApi {
    * @return Pet
    */
   public Pet getPetById(Long petId) throws ApiException {
-    Call call = getPetByIdCall(petId);
+    Call call = getPetByIdCall(petId, null, null);
     Type returnType = new TypeToken<Pet>(){}.getType();
     return apiClient.execute(call, returnType);
   }
@@ -313,15 +459,35 @@ public class PetApi {
    * @param callback The callback to be executed when the API call finishes
    * @return The request call
    */
-  public Call getPetByIdAsync(Long petId, ApiCallback<Pet> callback) throws ApiException {
-    Call call = getPetByIdCall(petId);
+  public Call getPetByIdAsync(Long petId, final ApiCallback<Pet> callback) throws ApiException {
+
+    ProgressResponseBody.ProgressListener progressListener = null;
+    ProgressRequestBody.ProgressRequestListener progressRequestListener = null;
+
+    if(callback != null) {
+      progressListener = new ProgressResponseBody.ProgressListener() {
+        @Override
+        public void update(long bytesRead, long contentLength, boolean done) {
+          callback.onDownloadProgress(bytesRead, contentLength, done);
+        } 
+      };
+
+      progressRequestListener = new ProgressRequestBody.ProgressRequestListener() {
+        @Override
+        public void onRequestProgress(long bytesWritten, long contentLength, boolean done) {
+          callback.onUploadProgress(bytesWritten, contentLength, done);
+        }
+      };
+    }
+
+    Call call = getPetByIdCall(petId, progressListener, progressRequestListener);
     Type returnType = new TypeToken<Pet>(){}.getType();
     apiClient.executeAsync(call, returnType, callback);
     return call;
   }
   
   /* Build call for updatePetWithForm */
-  private Call updatePetWithFormCall(String petId, String name, String status) throws ApiException {
+  private Call updatePetWithFormCall(String petId, String name, String status, final ProgressResponseBody.ProgressListener progressListener, final ProgressRequestBody.ProgressRequestListener progressRequestListener) throws ApiException {
     Object postBody = null;
     
     // verify the required parameter 'petId' is set
@@ -356,8 +522,20 @@ public class PetApi {
     final String contentType = apiClient.selectHeaderContentType(contentTypes);
     headerParams.put("Content-Type", contentType);
 
+    if(progressListener != null) {
+      apiClient.getHttpClient().networkInterceptors().add(new Interceptor() {
+      @Override
+      public Response intercept(Interceptor.Chain chain) throws IOException {
+        Response originalResponse = chain.proceed(chain.request());
+        return originalResponse.newBuilder()
+                .body(new ProgressResponseBody(originalResponse.body(), progressListener))
+                .build();
+        }
+      });
+    }
+
     String[] authNames = new String[] { "petstore_auth" };
-    return apiClient.buildCall(path, "POST", queryParams, postBody, headerParams, formParams, authNames);
+    return apiClient.buildCall(path, "POST", queryParams, postBody, headerParams, formParams, authNames, progressRequestListener);
   }
 
   /**
@@ -368,7 +546,7 @@ public class PetApi {
    * @param status Updated status of the pet
    */
   public void updatePetWithForm(String petId, String name, String status) throws ApiException {
-    Call call = updatePetWithFormCall(petId, name, status);
+    Call call = updatePetWithFormCall(petId, name, status, null, null);
     apiClient.execute(call);
   }
 
@@ -381,14 +559,34 @@ public class PetApi {
    * @param callback The callback to be executed when the API call finishes
    * @return The request call
    */
-  public Call updatePetWithFormAsync(String petId, String name, String status, ApiCallback<Void> callback) throws ApiException {
-    Call call = updatePetWithFormCall(petId, name, status);
+  public Call updatePetWithFormAsync(String petId, String name, String status, final ApiCallback<Void> callback) throws ApiException {
+
+    ProgressResponseBody.ProgressListener progressListener = null;
+    ProgressRequestBody.ProgressRequestListener progressRequestListener = null;
+
+    if(callback != null) {
+      progressListener = new ProgressResponseBody.ProgressListener() {
+        @Override
+        public void update(long bytesRead, long contentLength, boolean done) {
+          callback.onDownloadProgress(bytesRead, contentLength, done);
+        } 
+      };
+
+      progressRequestListener = new ProgressRequestBody.ProgressRequestListener() {
+        @Override
+        public void onRequestProgress(long bytesWritten, long contentLength, boolean done) {
+          callback.onUploadProgress(bytesWritten, contentLength, done);
+        }
+      };
+    }
+
+    Call call = updatePetWithFormCall(petId, name, status, progressListener, progressRequestListener);
     apiClient.executeAsync(call, callback);
     return call;
   }
   
   /* Build call for deletePet */
-  private Call deletePetCall(Long petId, String apiKey) throws ApiException {
+  private Call deletePetCall(Long petId, String apiKey, final ProgressResponseBody.ProgressListener progressListener, final ProgressRequestBody.ProgressRequestListener progressRequestListener) throws ApiException {
     Object postBody = null;
     
     // verify the required parameter 'petId' is set
@@ -421,8 +619,20 @@ public class PetApi {
     final String contentType = apiClient.selectHeaderContentType(contentTypes);
     headerParams.put("Content-Type", contentType);
 
+    if(progressListener != null) {
+      apiClient.getHttpClient().networkInterceptors().add(new Interceptor() {
+      @Override
+      public Response intercept(Interceptor.Chain chain) throws IOException {
+        Response originalResponse = chain.proceed(chain.request());
+        return originalResponse.newBuilder()
+                .body(new ProgressResponseBody(originalResponse.body(), progressListener))
+                .build();
+        }
+      });
+    }
+
     String[] authNames = new String[] { "petstore_auth" };
-    return apiClient.buildCall(path, "DELETE", queryParams, postBody, headerParams, formParams, authNames);
+    return apiClient.buildCall(path, "DELETE", queryParams, postBody, headerParams, formParams, authNames, progressRequestListener);
   }
 
   /**
@@ -432,7 +642,7 @@ public class PetApi {
    * @param apiKey 
    */
   public void deletePet(Long petId, String apiKey) throws ApiException {
-    Call call = deletePetCall(petId, apiKey);
+    Call call = deletePetCall(petId, apiKey, null, null);
     apiClient.execute(call);
   }
 
@@ -444,14 +654,34 @@ public class PetApi {
    * @param callback The callback to be executed when the API call finishes
    * @return The request call
    */
-  public Call deletePetAsync(Long petId, String apiKey, ApiCallback<Void> callback) throws ApiException {
-    Call call = deletePetCall(petId, apiKey);
+  public Call deletePetAsync(Long petId, String apiKey, final ApiCallback<Void> callback) throws ApiException {
+
+    ProgressResponseBody.ProgressListener progressListener = null;
+    ProgressRequestBody.ProgressRequestListener progressRequestListener = null;
+
+    if(callback != null) {
+      progressListener = new ProgressResponseBody.ProgressListener() {
+        @Override
+        public void update(long bytesRead, long contentLength, boolean done) {
+          callback.onDownloadProgress(bytesRead, contentLength, done);
+        } 
+      };
+
+      progressRequestListener = new ProgressRequestBody.ProgressRequestListener() {
+        @Override
+        public void onRequestProgress(long bytesWritten, long contentLength, boolean done) {
+          callback.onUploadProgress(bytesWritten, contentLength, done);
+        }
+      };
+    }
+
+    Call call = deletePetCall(petId, apiKey, progressListener, progressRequestListener);
     apiClient.executeAsync(call, callback);
     return call;
   }
   
   /* Build call for uploadFile */
-  private Call uploadFileCall(Long petId, String additionalMetadata, File file) throws ApiException {
+  private Call uploadFileCall(Long petId, String additionalMetadata, File file, final ProgressResponseBody.ProgressListener progressListener, final ProgressRequestBody.ProgressRequestListener progressRequestListener) throws ApiException {
     Object postBody = null;
     
     // verify the required parameter 'petId' is set
@@ -486,8 +716,20 @@ public class PetApi {
     final String contentType = apiClient.selectHeaderContentType(contentTypes);
     headerParams.put("Content-Type", contentType);
 
+    if(progressListener != null) {
+      apiClient.getHttpClient().networkInterceptors().add(new Interceptor() {
+      @Override
+      public Response intercept(Interceptor.Chain chain) throws IOException {
+        Response originalResponse = chain.proceed(chain.request());
+        return originalResponse.newBuilder()
+                .body(new ProgressResponseBody(originalResponse.body(), progressListener))
+                .build();
+        }
+      });
+    }
+
     String[] authNames = new String[] { "petstore_auth" };
-    return apiClient.buildCall(path, "POST", queryParams, postBody, headerParams, formParams, authNames);
+    return apiClient.buildCall(path, "POST", queryParams, postBody, headerParams, formParams, authNames, progressRequestListener);
   }
 
   /**
@@ -498,7 +740,7 @@ public class PetApi {
    * @param file file to upload
    */
   public void uploadFile(Long petId, String additionalMetadata, File file) throws ApiException {
-    Call call = uploadFileCall(petId, additionalMetadata, file);
+    Call call = uploadFileCall(petId, additionalMetadata, file, null, null);
     apiClient.execute(call);
   }
 
@@ -511,8 +753,28 @@ public class PetApi {
    * @param callback The callback to be executed when the API call finishes
    * @return The request call
    */
-  public Call uploadFileAsync(Long petId, String additionalMetadata, File file, ApiCallback<Void> callback) throws ApiException {
-    Call call = uploadFileCall(petId, additionalMetadata, file);
+  public Call uploadFileAsync(Long petId, String additionalMetadata, File file, final ApiCallback<Void> callback) throws ApiException {
+
+    ProgressResponseBody.ProgressListener progressListener = null;
+    ProgressRequestBody.ProgressRequestListener progressRequestListener = null;
+
+    if(callback != null) {
+      progressListener = new ProgressResponseBody.ProgressListener() {
+        @Override
+        public void update(long bytesRead, long contentLength, boolean done) {
+          callback.onDownloadProgress(bytesRead, contentLength, done);
+        } 
+      };
+
+      progressRequestListener = new ProgressRequestBody.ProgressRequestListener() {
+        @Override
+        public void onRequestProgress(long bytesWritten, long contentLength, boolean done) {
+          callback.onUploadProgress(bytesWritten, contentLength, done);
+        }
+      };
+    }
+
+    Call call = uploadFileCall(petId, additionalMetadata, file, progressListener, progressRequestListener);
     apiClient.executeAsync(call, callback);
     return call;
   }
diff --git a/samples/client/petstore/java/okhttp-gson/src/main/java/io/swagger/client/api/StoreApi.java b/samples/client/petstore/java/okhttp-gson/src/main/java/io/swagger/client/api/StoreApi.java
index cb780538e18..2235a73e0c3 100644
--- a/samples/client/petstore/java/okhttp-gson/src/main/java/io/swagger/client/api/StoreApi.java
+++ b/samples/client/petstore/java/okhttp-gson/src/main/java/io/swagger/client/api/StoreApi.java
@@ -5,10 +5,16 @@ import io.swagger.client.ApiClient;
 import io.swagger.client.ApiException;
 import io.swagger.client.Configuration;
 import io.swagger.client.Pair;
+import io.swagger.client.ProgressRequestBody;
+import io.swagger.client.ProgressResponseBody;
 
 import com.google.gson.reflect.TypeToken;
 
 import com.squareup.okhttp.Call;
+import com.squareup.okhttp.Interceptor;
+import com.squareup.okhttp.Response;
+
+import java.io.IOException;
 
 import java.util.Map;
 import io.swagger.client.model.Order;
@@ -37,7 +43,7 @@ public class StoreApi {
 
   
   /* Build call for getInventory */
-  private Call getInventoryCall() throws ApiException {
+  private Call getInventoryCall(, final ProgressResponseBody.ProgressListener progressListener, final ProgressRequestBody.ProgressRequestListener progressRequestListener) throws ApiException {
     Object postBody = null;
     
 
@@ -62,8 +68,20 @@ public class StoreApi {
     final String contentType = apiClient.selectHeaderContentType(contentTypes);
     headerParams.put("Content-Type", contentType);
 
+    if(progressListener != null) {
+      apiClient.getHttpClient().networkInterceptors().add(new Interceptor() {
+      @Override
+      public Response intercept(Interceptor.Chain chain) throws IOException {
+        Response originalResponse = chain.proceed(chain.request());
+        return originalResponse.newBuilder()
+                .body(new ProgressResponseBody(originalResponse.body(), progressListener))
+                .build();
+        }
+      });
+    }
+
     String[] authNames = new String[] { "api_key" };
-    return apiClient.buildCall(path, "GET", queryParams, postBody, headerParams, formParams, authNames);
+    return apiClient.buildCall(path, "GET", queryParams, postBody, headerParams, formParams, authNames, progressRequestListener);
   }
 
   /**
@@ -72,7 +90,7 @@ public class StoreApi {
    * @return Map<String, Integer>
    */
   public Map<String, Integer> getInventory() throws ApiException {
-    Call call = getInventoryCall();
+    Call call = getInventoryCall(, null, null);
     Type returnType = new TypeToken<Map<String, Integer>>(){}.getType();
     return apiClient.execute(call, returnType);
   }
@@ -83,15 +101,35 @@ public class StoreApi {
    * @param callback The callback to be executed when the API call finishes
    * @return The request call
    */
-  public Call getInventoryAsync(ApiCallback<Map<String, Integer>> callback) throws ApiException {
-    Call call = getInventoryCall();
+  public Call getInventoryAsync(final ApiCallback<Map<String, Integer>> callback) throws ApiException {
+
+    ProgressResponseBody.ProgressListener progressListener = null;
+    ProgressRequestBody.ProgressRequestListener progressRequestListener = null;
+
+    if(callback != null) {
+      progressListener = new ProgressResponseBody.ProgressListener() {
+        @Override
+        public void update(long bytesRead, long contentLength, boolean done) {
+          callback.onDownloadProgress(bytesRead, contentLength, done);
+        } 
+      };
+
+      progressRequestListener = new ProgressRequestBody.ProgressRequestListener() {
+        @Override
+        public void onRequestProgress(long bytesWritten, long contentLength, boolean done) {
+          callback.onUploadProgress(bytesWritten, contentLength, done);
+        }
+      };
+    }
+
+    Call call = getInventoryCall(, progressListener, progressRequestListener);
     Type returnType = new TypeToken<Map<String, Integer>>(){}.getType();
     apiClient.executeAsync(call, returnType, callback);
     return call;
   }
   
   /* Build call for placeOrder */
-  private Call placeOrderCall(Order body) throws ApiException {
+  private Call placeOrderCall(Order body, final ProgressResponseBody.ProgressListener progressListener, final ProgressRequestBody.ProgressRequestListener progressRequestListener) throws ApiException {
     Object postBody = body;
     
 
@@ -116,8 +154,20 @@ public class StoreApi {
     final String contentType = apiClient.selectHeaderContentType(contentTypes);
     headerParams.put("Content-Type", contentType);
 
+    if(progressListener != null) {
+      apiClient.getHttpClient().networkInterceptors().add(new Interceptor() {
+      @Override
+      public Response intercept(Interceptor.Chain chain) throws IOException {
+        Response originalResponse = chain.proceed(chain.request());
+        return originalResponse.newBuilder()
+                .body(new ProgressResponseBody(originalResponse.body(), progressListener))
+                .build();
+        }
+      });
+    }
+
     String[] authNames = new String[] {  };
-    return apiClient.buildCall(path, "POST", queryParams, postBody, headerParams, formParams, authNames);
+    return apiClient.buildCall(path, "POST", queryParams, postBody, headerParams, formParams, authNames, progressRequestListener);
   }
 
   /**
@@ -127,7 +177,7 @@ public class StoreApi {
    * @return Order
    */
   public Order placeOrder(Order body) throws ApiException {
-    Call call = placeOrderCall(body);
+    Call call = placeOrderCall(body, null, null);
     Type returnType = new TypeToken<Order>(){}.getType();
     return apiClient.execute(call, returnType);
   }
@@ -139,15 +189,35 @@ public class StoreApi {
    * @param callback The callback to be executed when the API call finishes
    * @return The request call
    */
-  public Call placeOrderAsync(Order body, ApiCallback<Order> callback) throws ApiException {
-    Call call = placeOrderCall(body);
+  public Call placeOrderAsync(Order body, final ApiCallback<Order> callback) throws ApiException {
+
+    ProgressResponseBody.ProgressListener progressListener = null;
+    ProgressRequestBody.ProgressRequestListener progressRequestListener = null;
+
+    if(callback != null) {
+      progressListener = new ProgressResponseBody.ProgressListener() {
+        @Override
+        public void update(long bytesRead, long contentLength, boolean done) {
+          callback.onDownloadProgress(bytesRead, contentLength, done);
+        } 
+      };
+
+      progressRequestListener = new ProgressRequestBody.ProgressRequestListener() {
+        @Override
+        public void onRequestProgress(long bytesWritten, long contentLength, boolean done) {
+          callback.onUploadProgress(bytesWritten, contentLength, done);
+        }
+      };
+    }
+
+    Call call = placeOrderCall(body, progressListener, progressRequestListener);
     Type returnType = new TypeToken<Order>(){}.getType();
     apiClient.executeAsync(call, returnType, callback);
     return call;
   }
   
   /* Build call for getOrderById */
-  private Call getOrderByIdCall(String orderId) throws ApiException {
+  private Call getOrderByIdCall(String orderId, final ProgressResponseBody.ProgressListener progressListener, final ProgressRequestBody.ProgressRequestListener progressRequestListener) throws ApiException {
     Object postBody = null;
     
     // verify the required parameter 'orderId' is set
@@ -178,8 +248,20 @@ public class StoreApi {
     final String contentType = apiClient.selectHeaderContentType(contentTypes);
     headerParams.put("Content-Type", contentType);
 
+    if(progressListener != null) {
+      apiClient.getHttpClient().networkInterceptors().add(new Interceptor() {
+      @Override
+      public Response intercept(Interceptor.Chain chain) throws IOException {
+        Response originalResponse = chain.proceed(chain.request());
+        return originalResponse.newBuilder()
+                .body(new ProgressResponseBody(originalResponse.body(), progressListener))
+                .build();
+        }
+      });
+    }
+
     String[] authNames = new String[] {  };
-    return apiClient.buildCall(path, "GET", queryParams, postBody, headerParams, formParams, authNames);
+    return apiClient.buildCall(path, "GET", queryParams, postBody, headerParams, formParams, authNames, progressRequestListener);
   }
 
   /**
@@ -189,7 +271,7 @@ public class StoreApi {
    * @return Order
    */
   public Order getOrderById(String orderId) throws ApiException {
-    Call call = getOrderByIdCall(orderId);
+    Call call = getOrderByIdCall(orderId, null, null);
     Type returnType = new TypeToken<Order>(){}.getType();
     return apiClient.execute(call, returnType);
   }
@@ -201,15 +283,35 @@ public class StoreApi {
    * @param callback The callback to be executed when the API call finishes
    * @return The request call
    */
-  public Call getOrderByIdAsync(String orderId, ApiCallback<Order> callback) throws ApiException {
-    Call call = getOrderByIdCall(orderId);
+  public Call getOrderByIdAsync(String orderId, final ApiCallback<Order> callback) throws ApiException {
+
+    ProgressResponseBody.ProgressListener progressListener = null;
+    ProgressRequestBody.ProgressRequestListener progressRequestListener = null;
+
+    if(callback != null) {
+      progressListener = new ProgressResponseBody.ProgressListener() {
+        @Override
+        public void update(long bytesRead, long contentLength, boolean done) {
+          callback.onDownloadProgress(bytesRead, contentLength, done);
+        } 
+      };
+
+      progressRequestListener = new ProgressRequestBody.ProgressRequestListener() {
+        @Override
+        public void onRequestProgress(long bytesWritten, long contentLength, boolean done) {
+          callback.onUploadProgress(bytesWritten, contentLength, done);
+        }
+      };
+    }
+
+    Call call = getOrderByIdCall(orderId, progressListener, progressRequestListener);
     Type returnType = new TypeToken<Order>(){}.getType();
     apiClient.executeAsync(call, returnType, callback);
     return call;
   }
   
   /* Build call for deleteOrder */
-  private Call deleteOrderCall(String orderId) throws ApiException {
+  private Call deleteOrderCall(String orderId, final ProgressResponseBody.ProgressListener progressListener, final ProgressRequestBody.ProgressRequestListener progressRequestListener) throws ApiException {
     Object postBody = null;
     
     // verify the required parameter 'orderId' is set
@@ -240,8 +342,20 @@ public class StoreApi {
     final String contentType = apiClient.selectHeaderContentType(contentTypes);
     headerParams.put("Content-Type", contentType);
 
+    if(progressListener != null) {
+      apiClient.getHttpClient().networkInterceptors().add(new Interceptor() {
+      @Override
+      public Response intercept(Interceptor.Chain chain) throws IOException {
+        Response originalResponse = chain.proceed(chain.request());
+        return originalResponse.newBuilder()
+                .body(new ProgressResponseBody(originalResponse.body(), progressListener))
+                .build();
+        }
+      });
+    }
+
     String[] authNames = new String[] {  };
-    return apiClient.buildCall(path, "DELETE", queryParams, postBody, headerParams, formParams, authNames);
+    return apiClient.buildCall(path, "DELETE", queryParams, postBody, headerParams, formParams, authNames, progressRequestListener);
   }
 
   /**
@@ -250,7 +364,7 @@ public class StoreApi {
    * @param orderId ID of the order that needs to be deleted
    */
   public void deleteOrder(String orderId) throws ApiException {
-    Call call = deleteOrderCall(orderId);
+    Call call = deleteOrderCall(orderId, null, null);
     apiClient.execute(call);
   }
 
@@ -261,8 +375,28 @@ public class StoreApi {
    * @param callback The callback to be executed when the API call finishes
    * @return The request call
    */
-  public Call deleteOrderAsync(String orderId, ApiCallback<Void> callback) throws ApiException {
-    Call call = deleteOrderCall(orderId);
+  public Call deleteOrderAsync(String orderId, final ApiCallback<Void> callback) throws ApiException {
+
+    ProgressResponseBody.ProgressListener progressListener = null;
+    ProgressRequestBody.ProgressRequestListener progressRequestListener = null;
+
+    if(callback != null) {
+      progressListener = new ProgressResponseBody.ProgressListener() {
+        @Override
+        public void update(long bytesRead, long contentLength, boolean done) {
+          callback.onDownloadProgress(bytesRead, contentLength, done);
+        } 
+      };
+
+      progressRequestListener = new ProgressRequestBody.ProgressRequestListener() {
+        @Override
+        public void onRequestProgress(long bytesWritten, long contentLength, boolean done) {
+          callback.onUploadProgress(bytesWritten, contentLength, done);
+        }
+      };
+    }
+
+    Call call = deleteOrderCall(orderId, progressListener, progressRequestListener);
     apiClient.executeAsync(call, callback);
     return call;
   }
diff --git a/samples/client/petstore/java/okhttp-gson/src/main/java/io/swagger/client/api/UserApi.java b/samples/client/petstore/java/okhttp-gson/src/main/java/io/swagger/client/api/UserApi.java
index a04470b3b40..4f364db4b12 100644
--- a/samples/client/petstore/java/okhttp-gson/src/main/java/io/swagger/client/api/UserApi.java
+++ b/samples/client/petstore/java/okhttp-gson/src/main/java/io/swagger/client/api/UserApi.java
@@ -5,10 +5,16 @@ import io.swagger.client.ApiClient;
 import io.swagger.client.ApiException;
 import io.swagger.client.Configuration;
 import io.swagger.client.Pair;
+import io.swagger.client.ProgressRequestBody;
+import io.swagger.client.ProgressResponseBody;
 
 import com.google.gson.reflect.TypeToken;
 
 import com.squareup.okhttp.Call;
+import com.squareup.okhttp.Interceptor;
+import com.squareup.okhttp.Response;
+
+import java.io.IOException;
 
 import io.swagger.client.model.User;
 import java.util.*;
@@ -37,7 +43,7 @@ public class UserApi {
 
   
   /* Build call for createUser */
-  private Call createUserCall(User body) throws ApiException {
+  private Call createUserCall(User body, final ProgressResponseBody.ProgressListener progressListener, final ProgressRequestBody.ProgressRequestListener progressRequestListener) throws ApiException {
     Object postBody = body;
     
 
@@ -62,8 +68,20 @@ public class UserApi {
     final String contentType = apiClient.selectHeaderContentType(contentTypes);
     headerParams.put("Content-Type", contentType);
 
+    if(progressListener != null) {
+      apiClient.getHttpClient().networkInterceptors().add(new Interceptor() {
+      @Override
+      public Response intercept(Interceptor.Chain chain) throws IOException {
+        Response originalResponse = chain.proceed(chain.request());
+        return originalResponse.newBuilder()
+                .body(new ProgressResponseBody(originalResponse.body(), progressListener))
+                .build();
+        }
+      });
+    }
+
     String[] authNames = new String[] {  };
-    return apiClient.buildCall(path, "POST", queryParams, postBody, headerParams, formParams, authNames);
+    return apiClient.buildCall(path, "POST", queryParams, postBody, headerParams, formParams, authNames, progressRequestListener);
   }
 
   /**
@@ -72,7 +90,7 @@ public class UserApi {
    * @param body Created user object
    */
   public void createUser(User body) throws ApiException {
-    Call call = createUserCall(body);
+    Call call = createUserCall(body, null, null);
     apiClient.execute(call);
   }
 
@@ -83,14 +101,34 @@ public class UserApi {
    * @param callback The callback to be executed when the API call finishes
    * @return The request call
    */
-  public Call createUserAsync(User body, ApiCallback<Void> callback) throws ApiException {
-    Call call = createUserCall(body);
+  public Call createUserAsync(User body, final ApiCallback<Void> callback) throws ApiException {
+
+    ProgressResponseBody.ProgressListener progressListener = null;
+    ProgressRequestBody.ProgressRequestListener progressRequestListener = null;
+
+    if(callback != null) {
+      progressListener = new ProgressResponseBody.ProgressListener() {
+        @Override
+        public void update(long bytesRead, long contentLength, boolean done) {
+          callback.onDownloadProgress(bytesRead, contentLength, done);
+        } 
+      };
+
+      progressRequestListener = new ProgressRequestBody.ProgressRequestListener() {
+        @Override
+        public void onRequestProgress(long bytesWritten, long contentLength, boolean done) {
+          callback.onUploadProgress(bytesWritten, contentLength, done);
+        }
+      };
+    }
+
+    Call call = createUserCall(body, progressListener, progressRequestListener);
     apiClient.executeAsync(call, callback);
     return call;
   }
   
   /* Build call for createUsersWithArrayInput */
-  private Call createUsersWithArrayInputCall(List<User> body) throws ApiException {
+  private Call createUsersWithArrayInputCall(List<User> body, final ProgressResponseBody.ProgressListener progressListener, final ProgressRequestBody.ProgressRequestListener progressRequestListener) throws ApiException {
     Object postBody = body;
     
 
@@ -115,8 +153,20 @@ public class UserApi {
     final String contentType = apiClient.selectHeaderContentType(contentTypes);
     headerParams.put("Content-Type", contentType);
 
+    if(progressListener != null) {
+      apiClient.getHttpClient().networkInterceptors().add(new Interceptor() {
+      @Override
+      public Response intercept(Interceptor.Chain chain) throws IOException {
+        Response originalResponse = chain.proceed(chain.request());
+        return originalResponse.newBuilder()
+                .body(new ProgressResponseBody(originalResponse.body(), progressListener))
+                .build();
+        }
+      });
+    }
+
     String[] authNames = new String[] {  };
-    return apiClient.buildCall(path, "POST", queryParams, postBody, headerParams, formParams, authNames);
+    return apiClient.buildCall(path, "POST", queryParams, postBody, headerParams, formParams, authNames, progressRequestListener);
   }
 
   /**
@@ -125,7 +175,7 @@ public class UserApi {
    * @param body List of user object
    */
   public void createUsersWithArrayInput(List<User> body) throws ApiException {
-    Call call = createUsersWithArrayInputCall(body);
+    Call call = createUsersWithArrayInputCall(body, null, null);
     apiClient.execute(call);
   }
 
@@ -136,14 +186,34 @@ public class UserApi {
    * @param callback The callback to be executed when the API call finishes
    * @return The request call
    */
-  public Call createUsersWithArrayInputAsync(List<User> body, ApiCallback<Void> callback) throws ApiException {
-    Call call = createUsersWithArrayInputCall(body);
+  public Call createUsersWithArrayInputAsync(List<User> body, final ApiCallback<Void> callback) throws ApiException {
+
+    ProgressResponseBody.ProgressListener progressListener = null;
+    ProgressRequestBody.ProgressRequestListener progressRequestListener = null;
+
+    if(callback != null) {
+      progressListener = new ProgressResponseBody.ProgressListener() {
+        @Override
+        public void update(long bytesRead, long contentLength, boolean done) {
+          callback.onDownloadProgress(bytesRead, contentLength, done);
+        } 
+      };
+
+      progressRequestListener = new ProgressRequestBody.ProgressRequestListener() {
+        @Override
+        public void onRequestProgress(long bytesWritten, long contentLength, boolean done) {
+          callback.onUploadProgress(bytesWritten, contentLength, done);
+        }
+      };
+    }
+
+    Call call = createUsersWithArrayInputCall(body, progressListener, progressRequestListener);
     apiClient.executeAsync(call, callback);
     return call;
   }
   
   /* Build call for createUsersWithListInput */
-  private Call createUsersWithListInputCall(List<User> body) throws ApiException {
+  private Call createUsersWithListInputCall(List<User> body, final ProgressResponseBody.ProgressListener progressListener, final ProgressRequestBody.ProgressRequestListener progressRequestListener) throws ApiException {
     Object postBody = body;
     
 
@@ -168,8 +238,20 @@ public class UserApi {
     final String contentType = apiClient.selectHeaderContentType(contentTypes);
     headerParams.put("Content-Type", contentType);
 
+    if(progressListener != null) {
+      apiClient.getHttpClient().networkInterceptors().add(new Interceptor() {
+      @Override
+      public Response intercept(Interceptor.Chain chain) throws IOException {
+        Response originalResponse = chain.proceed(chain.request());
+        return originalResponse.newBuilder()
+                .body(new ProgressResponseBody(originalResponse.body(), progressListener))
+                .build();
+        }
+      });
+    }
+
     String[] authNames = new String[] {  };
-    return apiClient.buildCall(path, "POST", queryParams, postBody, headerParams, formParams, authNames);
+    return apiClient.buildCall(path, "POST", queryParams, postBody, headerParams, formParams, authNames, progressRequestListener);
   }
 
   /**
@@ -178,7 +260,7 @@ public class UserApi {
    * @param body List of user object
    */
   public void createUsersWithListInput(List<User> body) throws ApiException {
-    Call call = createUsersWithListInputCall(body);
+    Call call = createUsersWithListInputCall(body, null, null);
     apiClient.execute(call);
   }
 
@@ -189,14 +271,34 @@ public class UserApi {
    * @param callback The callback to be executed when the API call finishes
    * @return The request call
    */
-  public Call createUsersWithListInputAsync(List<User> body, ApiCallback<Void> callback) throws ApiException {
-    Call call = createUsersWithListInputCall(body);
+  public Call createUsersWithListInputAsync(List<User> body, final ApiCallback<Void> callback) throws ApiException {
+
+    ProgressResponseBody.ProgressListener progressListener = null;
+    ProgressRequestBody.ProgressRequestListener progressRequestListener = null;
+
+    if(callback != null) {
+      progressListener = new ProgressResponseBody.ProgressListener() {
+        @Override
+        public void update(long bytesRead, long contentLength, boolean done) {
+          callback.onDownloadProgress(bytesRead, contentLength, done);
+        } 
+      };
+
+      progressRequestListener = new ProgressRequestBody.ProgressRequestListener() {
+        @Override
+        public void onRequestProgress(long bytesWritten, long contentLength, boolean done) {
+          callback.onUploadProgress(bytesWritten, contentLength, done);
+        }
+      };
+    }
+
+    Call call = createUsersWithListInputCall(body, progressListener, progressRequestListener);
     apiClient.executeAsync(call, callback);
     return call;
   }
   
   /* Build call for loginUser */
-  private Call loginUserCall(String username, String password) throws ApiException {
+  private Call loginUserCall(String username, String password, final ProgressResponseBody.ProgressListener progressListener, final ProgressRequestBody.ProgressRequestListener progressRequestListener) throws ApiException {
     Object postBody = null;
     
 
@@ -225,8 +327,20 @@ public class UserApi {
     final String contentType = apiClient.selectHeaderContentType(contentTypes);
     headerParams.put("Content-Type", contentType);
 
+    if(progressListener != null) {
+      apiClient.getHttpClient().networkInterceptors().add(new Interceptor() {
+      @Override
+      public Response intercept(Interceptor.Chain chain) throws IOException {
+        Response originalResponse = chain.proceed(chain.request());
+        return originalResponse.newBuilder()
+                .body(new ProgressResponseBody(originalResponse.body(), progressListener))
+                .build();
+        }
+      });
+    }
+
     String[] authNames = new String[] {  };
-    return apiClient.buildCall(path, "GET", queryParams, postBody, headerParams, formParams, authNames);
+    return apiClient.buildCall(path, "GET", queryParams, postBody, headerParams, formParams, authNames, progressRequestListener);
   }
 
   /**
@@ -237,7 +351,7 @@ public class UserApi {
    * @return String
    */
   public String loginUser(String username, String password) throws ApiException {
-    Call call = loginUserCall(username, password);
+    Call call = loginUserCall(username, password, null, null);
     Type returnType = new TypeToken<String>(){}.getType();
     return apiClient.execute(call, returnType);
   }
@@ -250,15 +364,35 @@ public class UserApi {
    * @param callback The callback to be executed when the API call finishes
    * @return The request call
    */
-  public Call loginUserAsync(String username, String password, ApiCallback<String> callback) throws ApiException {
-    Call call = loginUserCall(username, password);
+  public Call loginUserAsync(String username, String password, final ApiCallback<String> callback) throws ApiException {
+
+    ProgressResponseBody.ProgressListener progressListener = null;
+    ProgressRequestBody.ProgressRequestListener progressRequestListener = null;
+
+    if(callback != null) {
+      progressListener = new ProgressResponseBody.ProgressListener() {
+        @Override
+        public void update(long bytesRead, long contentLength, boolean done) {
+          callback.onDownloadProgress(bytesRead, contentLength, done);
+        } 
+      };
+
+      progressRequestListener = new ProgressRequestBody.ProgressRequestListener() {
+        @Override
+        public void onRequestProgress(long bytesWritten, long contentLength, boolean done) {
+          callback.onUploadProgress(bytesWritten, contentLength, done);
+        }
+      };
+    }
+
+    Call call = loginUserCall(username, password, progressListener, progressRequestListener);
     Type returnType = new TypeToken<String>(){}.getType();
     apiClient.executeAsync(call, returnType, callback);
     return call;
   }
   
   /* Build call for logoutUser */
-  private Call logoutUserCall() throws ApiException {
+  private Call logoutUserCall(, final ProgressResponseBody.ProgressListener progressListener, final ProgressRequestBody.ProgressRequestListener progressRequestListener) throws ApiException {
     Object postBody = null;
     
 
@@ -283,8 +417,20 @@ public class UserApi {
     final String contentType = apiClient.selectHeaderContentType(contentTypes);
     headerParams.put("Content-Type", contentType);
 
+    if(progressListener != null) {
+      apiClient.getHttpClient().networkInterceptors().add(new Interceptor() {
+      @Override
+      public Response intercept(Interceptor.Chain chain) throws IOException {
+        Response originalResponse = chain.proceed(chain.request());
+        return originalResponse.newBuilder()
+                .body(new ProgressResponseBody(originalResponse.body(), progressListener))
+                .build();
+        }
+      });
+    }
+
     String[] authNames = new String[] {  };
-    return apiClient.buildCall(path, "GET", queryParams, postBody, headerParams, formParams, authNames);
+    return apiClient.buildCall(path, "GET", queryParams, postBody, headerParams, formParams, authNames, progressRequestListener);
   }
 
   /**
@@ -292,7 +438,7 @@ public class UserApi {
    * 
    */
   public void logoutUser() throws ApiException {
-    Call call = logoutUserCall();
+    Call call = logoutUserCall(, null, null);
     apiClient.execute(call);
   }
 
@@ -302,14 +448,34 @@ public class UserApi {
    * @param callback The callback to be executed when the API call finishes
    * @return The request call
    */
-  public Call logoutUserAsync(ApiCallback<Void> callback) throws ApiException {
-    Call call = logoutUserCall();
+  public Call logoutUserAsync(final ApiCallback<Void> callback) throws ApiException {
+
+    ProgressResponseBody.ProgressListener progressListener = null;
+    ProgressRequestBody.ProgressRequestListener progressRequestListener = null;
+
+    if(callback != null) {
+      progressListener = new ProgressResponseBody.ProgressListener() {
+        @Override
+        public void update(long bytesRead, long contentLength, boolean done) {
+          callback.onDownloadProgress(bytesRead, contentLength, done);
+        } 
+      };
+
+      progressRequestListener = new ProgressRequestBody.ProgressRequestListener() {
+        @Override
+        public void onRequestProgress(long bytesWritten, long contentLength, boolean done) {
+          callback.onUploadProgress(bytesWritten, contentLength, done);
+        }
+      };
+    }
+
+    Call call = logoutUserCall(, progressListener, progressRequestListener);
     apiClient.executeAsync(call, callback);
     return call;
   }
   
   /* Build call for getUserByName */
-  private Call getUserByNameCall(String username) throws ApiException {
+  private Call getUserByNameCall(String username, final ProgressResponseBody.ProgressListener progressListener, final ProgressRequestBody.ProgressRequestListener progressRequestListener) throws ApiException {
     Object postBody = null;
     
     // verify the required parameter 'username' is set
@@ -340,8 +506,20 @@ public class UserApi {
     final String contentType = apiClient.selectHeaderContentType(contentTypes);
     headerParams.put("Content-Type", contentType);
 
+    if(progressListener != null) {
+      apiClient.getHttpClient().networkInterceptors().add(new Interceptor() {
+      @Override
+      public Response intercept(Interceptor.Chain chain) throws IOException {
+        Response originalResponse = chain.proceed(chain.request());
+        return originalResponse.newBuilder()
+                .body(new ProgressResponseBody(originalResponse.body(), progressListener))
+                .build();
+        }
+      });
+    }
+
     String[] authNames = new String[] {  };
-    return apiClient.buildCall(path, "GET", queryParams, postBody, headerParams, formParams, authNames);
+    return apiClient.buildCall(path, "GET", queryParams, postBody, headerParams, formParams, authNames, progressRequestListener);
   }
 
   /**
@@ -351,7 +529,7 @@ public class UserApi {
    * @return User
    */
   public User getUserByName(String username) throws ApiException {
-    Call call = getUserByNameCall(username);
+    Call call = getUserByNameCall(username, null, null);
     Type returnType = new TypeToken<User>(){}.getType();
     return apiClient.execute(call, returnType);
   }
@@ -363,15 +541,35 @@ public class UserApi {
    * @param callback The callback to be executed when the API call finishes
    * @return The request call
    */
-  public Call getUserByNameAsync(String username, ApiCallback<User> callback) throws ApiException {
-    Call call = getUserByNameCall(username);
+  public Call getUserByNameAsync(String username, final ApiCallback<User> callback) throws ApiException {
+
+    ProgressResponseBody.ProgressListener progressListener = null;
+    ProgressRequestBody.ProgressRequestListener progressRequestListener = null;
+
+    if(callback != null) {
+      progressListener = new ProgressResponseBody.ProgressListener() {
+        @Override
+        public void update(long bytesRead, long contentLength, boolean done) {
+          callback.onDownloadProgress(bytesRead, contentLength, done);
+        } 
+      };
+
+      progressRequestListener = new ProgressRequestBody.ProgressRequestListener() {
+        @Override
+        public void onRequestProgress(long bytesWritten, long contentLength, boolean done) {
+          callback.onUploadProgress(bytesWritten, contentLength, done);
+        }
+      };
+    }
+
+    Call call = getUserByNameCall(username, progressListener, progressRequestListener);
     Type returnType = new TypeToken<User>(){}.getType();
     apiClient.executeAsync(call, returnType, callback);
     return call;
   }
   
   /* Build call for updateUser */
-  private Call updateUserCall(String username, User body) throws ApiException {
+  private Call updateUserCall(String username, User body, final ProgressResponseBody.ProgressListener progressListener, final ProgressRequestBody.ProgressRequestListener progressRequestListener) throws ApiException {
     Object postBody = body;
     
     // verify the required parameter 'username' is set
@@ -402,8 +600,20 @@ public class UserApi {
     final String contentType = apiClient.selectHeaderContentType(contentTypes);
     headerParams.put("Content-Type", contentType);
 
+    if(progressListener != null) {
+      apiClient.getHttpClient().networkInterceptors().add(new Interceptor() {
+      @Override
+      public Response intercept(Interceptor.Chain chain) throws IOException {
+        Response originalResponse = chain.proceed(chain.request());
+        return originalResponse.newBuilder()
+                .body(new ProgressResponseBody(originalResponse.body(), progressListener))
+                .build();
+        }
+      });
+    }
+
     String[] authNames = new String[] {  };
-    return apiClient.buildCall(path, "PUT", queryParams, postBody, headerParams, formParams, authNames);
+    return apiClient.buildCall(path, "PUT", queryParams, postBody, headerParams, formParams, authNames, progressRequestListener);
   }
 
   /**
@@ -413,7 +623,7 @@ public class UserApi {
    * @param body Updated user object
    */
   public void updateUser(String username, User body) throws ApiException {
-    Call call = updateUserCall(username, body);
+    Call call = updateUserCall(username, body, null, null);
     apiClient.execute(call);
   }
 
@@ -425,14 +635,34 @@ public class UserApi {
    * @param callback The callback to be executed when the API call finishes
    * @return The request call
    */
-  public Call updateUserAsync(String username, User body, ApiCallback<Void> callback) throws ApiException {
-    Call call = updateUserCall(username, body);
+  public Call updateUserAsync(String username, User body, final ApiCallback<Void> callback) throws ApiException {
+
+    ProgressResponseBody.ProgressListener progressListener = null;
+    ProgressRequestBody.ProgressRequestListener progressRequestListener = null;
+
+    if(callback != null) {
+      progressListener = new ProgressResponseBody.ProgressListener() {
+        @Override
+        public void update(long bytesRead, long contentLength, boolean done) {
+          callback.onDownloadProgress(bytesRead, contentLength, done);
+        } 
+      };
+
+      progressRequestListener = new ProgressRequestBody.ProgressRequestListener() {
+        @Override
+        public void onRequestProgress(long bytesWritten, long contentLength, boolean done) {
+          callback.onUploadProgress(bytesWritten, contentLength, done);
+        }
+      };
+    }
+
+    Call call = updateUserCall(username, body, progressListener, progressRequestListener);
     apiClient.executeAsync(call, callback);
     return call;
   }
   
   /* Build call for deleteUser */
-  private Call deleteUserCall(String username) throws ApiException {
+  private Call deleteUserCall(String username, final ProgressResponseBody.ProgressListener progressListener, final ProgressRequestBody.ProgressRequestListener progressRequestListener) throws ApiException {
     Object postBody = null;
     
     // verify the required parameter 'username' is set
@@ -463,8 +693,20 @@ public class UserApi {
     final String contentType = apiClient.selectHeaderContentType(contentTypes);
     headerParams.put("Content-Type", contentType);
 
+    if(progressListener != null) {
+      apiClient.getHttpClient().networkInterceptors().add(new Interceptor() {
+      @Override
+      public Response intercept(Interceptor.Chain chain) throws IOException {
+        Response originalResponse = chain.proceed(chain.request());
+        return originalResponse.newBuilder()
+                .body(new ProgressResponseBody(originalResponse.body(), progressListener))
+                .build();
+        }
+      });
+    }
+
     String[] authNames = new String[] {  };
-    return apiClient.buildCall(path, "DELETE", queryParams, postBody, headerParams, formParams, authNames);
+    return apiClient.buildCall(path, "DELETE", queryParams, postBody, headerParams, formParams, authNames, progressRequestListener);
   }
 
   /**
@@ -473,7 +715,7 @@ public class UserApi {
    * @param username The name that needs to be deleted
    */
   public void deleteUser(String username) throws ApiException {
-    Call call = deleteUserCall(username);
+    Call call = deleteUserCall(username, null, null);
     apiClient.execute(call);
   }
 
@@ -484,8 +726,28 @@ public class UserApi {
    * @param callback The callback to be executed when the API call finishes
    * @return The request call
    */
-  public Call deleteUserAsync(String username, ApiCallback<Void> callback) throws ApiException {
-    Call call = deleteUserCall(username);
+  public Call deleteUserAsync(String username, final ApiCallback<Void> callback) throws ApiException {
+
+    ProgressResponseBody.ProgressListener progressListener = null;
+    ProgressRequestBody.ProgressRequestListener progressRequestListener = null;
+
+    if(callback != null) {
+      progressListener = new ProgressResponseBody.ProgressListener() {
+        @Override
+        public void update(long bytesRead, long contentLength, boolean done) {
+          callback.onDownloadProgress(bytesRead, contentLength, done);
+        } 
+      };
+
+      progressRequestListener = new ProgressRequestBody.ProgressRequestListener() {
+        @Override
+        public void onRequestProgress(long bytesWritten, long contentLength, boolean done) {
+          callback.onUploadProgress(bytesWritten, contentLength, done);
+        }
+      };
+    }
+
+    Call call = deleteUserCall(username, progressListener, progressRequestListener);
     apiClient.executeAsync(call, callback);
     return call;
   }
diff --git a/samples/client/petstore/java/okhttp-gson/src/main/java/io/swagger/client/auth/ApiKeyAuth.java b/samples/client/petstore/java/okhttp-gson/src/main/java/io/swagger/client/auth/ApiKeyAuth.java
index c072321f457..600455b7592 100644
--- a/samples/client/petstore/java/okhttp-gson/src/main/java/io/swagger/client/auth/ApiKeyAuth.java
+++ b/samples/client/petstore/java/okhttp-gson/src/main/java/io/swagger/client/auth/ApiKeyAuth.java
@@ -5,7 +5,7 @@ import io.swagger.client.Pair;
 import java.util.Map;
 import java.util.List;
 
-@javax.annotation.Generated(value = "class io.swagger.codegen.languages.JavaClientCodegen", date = "2015-10-20T11:42:25.339-07:00")
+@javax.annotation.Generated(value = "class io.swagger.codegen.languages.JavaClientCodegen", date = "2015-11-21T19:41:14.431+08:00")
 public class ApiKeyAuth implements Authentication {
   private final String location;
   private final String paramName;
diff --git a/samples/client/petstore/java/okhttp-gson/src/main/java/io/swagger/client/auth/Authentication.java b/samples/client/petstore/java/okhttp-gson/src/main/java/io/swagger/client/auth/Authentication.java
index 18ca4080c2e..aa2efcd7e9b 100644
--- a/samples/client/petstore/java/okhttp-gson/src/main/java/io/swagger/client/auth/Authentication.java
+++ b/samples/client/petstore/java/okhttp-gson/src/main/java/io/swagger/client/auth/Authentication.java
@@ -5,7 +5,7 @@ import io.swagger.client.Pair;
 import java.util.Map;
 import java.util.List;
 
-@javax.annotation.Generated(value = "class io.swagger.codegen.languages.JavaClientCodegen", date = "2015-10-20T11:42:25.339-07:00")
+@javax.annotation.Generated(value = "class io.swagger.codegen.languages.JavaClientCodegen", date = "2015-11-21T19:41:14.431+08:00")
 public interface Authentication {
   /** Apply authentication settings to header and query params. */
   void applyToParams(List<Pair> queryParams, Map<String, String> headerParams);
diff --git a/samples/client/petstore/java/okhttp-gson/src/main/java/io/swagger/client/auth/OAuth.java b/samples/client/petstore/java/okhttp-gson/src/main/java/io/swagger/client/auth/OAuth.java
index bc6473d110f..8463a8bbd28 100644
--- a/samples/client/petstore/java/okhttp-gson/src/main/java/io/swagger/client/auth/OAuth.java
+++ b/samples/client/petstore/java/okhttp-gson/src/main/java/io/swagger/client/auth/OAuth.java
@@ -5,7 +5,7 @@ import io.swagger.client.Pair;
 import java.util.Map;
 import java.util.List;
 
-@javax.annotation.Generated(value = "class io.swagger.codegen.languages.JavaClientCodegen", date = "2015-11-02T22:14:00.422+08:00")
+@javax.annotation.Generated(value = "class io.swagger.codegen.languages.JavaClientCodegen", date = "2015-11-21T19:41:14.431+08:00")
 public class OAuth implements Authentication {
   private String accessToken;