使用DeferredResult时，ResponseEntity得正文为空

Question

我正在使用springboot 1.4.4创建一个异步RESTful API。除了成功处理请求时，DeferredResult >的正文和200 OK状态代码始终为空之外，其他操作都很正常，即使我显式地将字符串值设置到result对象。代码如下所示：

RestController IMPL：

 @Async
  public DeferredResult<ResponseEntity<String>> parseWithLongDelay(    
     @RequestBody MyRequestObject req){
     DeferredResult<ResponseEntity<String>> result = new DeferredResult<>();
     :
     :
     result.setResult(new ResponseEntity<String>("That big zip file successfully parsed.", HttpStatus.OK));
     return result;
  }

客户端：

 @Test
 public void test(){
    ListenableFuture<ResponseEntity<String>> futureEntity = new AsyncRestTemplate().postForEntity(url, requestEntity,
    String.class);
    futureEntity.addCallback(new MyFutureCallback());
    :
  }
  class MyFutureCallback implements ListenableFutureCallback<ResponseEntity<String>> {
  @Override
  public void onSuccess(ResponseEntity<String> entity) {
   String body = entity.getBody();
   log.info("response content: " + body);
   //always get null body, there is no server side exception or error
   //when callback happens
 }
}  

我期待字符串“That big zip file successfully parsed.”body get return而不是Null？有线索吗？请救命！

Answer 1

我发现在我的例子中，ShalloweTagHeaderFilter导致了错误。这是我在休息法中为了避免身体空虚所做的：

ShallowEtagHeaderFilter.disableContentCaching(request);