symfony2无法在控制器中接收json响应

我正在使用FOSRestBundle开发REST API。我无法从控制器发送JSON响应。我正在将FooControllerFoo的fooAction的请求转发到BarController的某个操作，当我试图从该操作返回JSON响应时，我得到的是空白数组。

这是一个场景：

FooController.php

class FooController  extends FOSRestController {
...
public function fooAction() {
 ...
    $response = $this->forward('ApplicationPApiBundle:bar:getByZipCode', array(), array('zipcode' => $zipcode));
    print_r($response);  //getting blank array here
...
}
}

BarController.php

class BarController  extends FOSRestController {
    ...
    public function getByZipCodeAction() {
     ...
       $response = new Response((array("one"=>"1", "two"=> "2")));
       $response->headers->set('Content-Type', 'application/json');
       // print_r($response);  // after printing I can see data in json format
       return $response;
     }
    }

当我在FooController的fooAction中打印响应时，我将其视为一个空数组，但当我在返回它之前在Barcontroller的getByZipCodeAction中打印它时，我会看到具有json内容的正确响应对象。

有人能帮我弄清楚这里发生了什么吗？

编辑：返回之前在Barcontroller中打印的响应对象：

Symfony'Component'HttpFoundation'Response Object
(
    [headers] => Symfony'Component'HttpFoundation'ResponseHeaderBag Object
        (
            [computedCacheControl:protected] => Array
                (
                    [no-cache] => 1
                )
            [cookies:protected] => Array
                (
                )
            [headerNames:protected] => Array
                (
                    [cache-control] => Cache-Control
                    [date] => Date
                    [content-type] => Content-Type
                )
            [headers:protected] => Array
                (
                    [cache-control] => Array
                        (
                            [0] => no-cache
                        )
                    [date] => Array
                        (
                            [0] => Wed, 24 Sep 2014 13:48:49 GMT
                        )
                    [content-type] => Array
                        (
                            [0] => application/json
                        )
                )
            [cacheControl:protected] => Array
                (
                )
        )
    [content:protected] => {"one":"1","two":"2"}
    [version:protected] => 1.0
    [statusCode:protected] => 200
    [statusText:protected] => OK
    [charset:protected] => 
)

=============================================

从转发操作获得响应后，Foocontroller中打印的响应对象：

Symfony'Component'HttpFoundation'Response Object
(
    [headers] => Symfony'Component'HttpFoundation'ResponseHeaderBag Object
        (
            [computedCacheControl:protected] => Array
                (
                    [no-cache] => 1
                )
            [cookies:protected] => Array
                (
                )
            [headerNames:protected] => Array
                (
                    [cache-control] => Cache-Control
                    [date] => Date
                    [content-type] => Content-Type
                    [x-debug-token] => X-Debug-Token
                    [x-debug-token-link] => X-Debug-Token-Link
                )
            [headers:protected] => Array
                (
                    [cache-control] => Array
                        (
                            [0] => no-cache
                        )
                    [date] => Array
                        (
                            [0] => Wed, 24 Sep 2014 13:48:49 GMT
                        )
                    [content-type] => Array
                        (
                            [0] => application/json
                        )
                    [x-debug-token] => Array
                        (
                            [0] => 168be3
                        )
                    [x-debug-token-link] => Array
                        (
                            [0] => /app_dev.php/_profiler/168be3
                        )
                )
            [cacheControl:protected] => Array
                (
                )
        )
    [content:protected] => []
    [version:protected] => 1.0
    [statusCode:protected] => 200
    [statusText:protected] => OK
    [charset:protected] => 
)

请注意内容为空。