Question

我正在实施long polling as per the Spring blog from some time ago。

这里我的转换方法具有与以前相同的响应签名，但它现在使用长轮询而不是立即响应：

private Map<String, DeferredResult<ResponseEntity<?>>> requests = new ConcurrentHashMap<>();

@RequestMapping(value = "/{uuid}", method = RequestMethod.GET)
public DeferredResult<ResponseEntity<?>> poll(@PathVariable("uuid") final String uuid) {
    // Create & store a new instance
    ResponseEntity<?> pendingOnTimeout = ResponseEntity.accepted().build();
    DeferredResult<ResponseEntity<?>> deferredResult = new DeferredResult<>(TWENTYFIVE_SECONDS, pendingOnTimeout);
    requests.put(uuid, deferredResult);

    // Clean up poll requests when done
    deferredResult.onCompletion(() -> {
        requests.remove(deferredResult);
    });

    // Set result if already available
    Task task = taskHolder.retrieve(uuid);
    if (task == null)
        deferredResult.setResult(ResponseEntity.status(HttpStatus.GONE).build());
    else
        // Done (or canceled): Redirect to retrieve file contents
        if (task.getFutureFile().isDone())
            deferredResult.setResult(ResponseEntity.created(RetrieveController.uri(uuid)).build());

    // Return result
    return deferredResult;
}

特别是当请求花费太长时间（我之前立即返回）时，我想返回pendingOnTimeout响应，以防止代理切断请求。

现在我觉得我已经按原样运行，但是我想编写一个证明这一点的单元测试。但是，我使用MockMvc（通过webAppContextSetup）的所有尝试都无法为我提供断言我获得accepted标头的方法。例如，当我尝试以下内容时：

@Test
public void pollPending() throws Exception {
    MvcResult result = mockMvc.perform(get("/poll/{uuid}", uuidPending)).andReturn();
    mockMvc.perform(asyncDispatch(result))
            .andExpect(status().isAccepted());
}

我得到以下stacktrace：

java.lang.IllegalStateException：处理程序的异步结果[public org.springframework.web.context.request.async.DeferredResult>在指定的timeToWait = 25000期间未设置nl.bioprodict.blast.api.PollController.poll（java.lang.String）] 在org.springframework.util.Assert.state（Assert.java:392）在org.springframework.test.web.servlet.DefaultMvcResult.getAsyncResult（DefaultMvcResult.java:143）在org.springframework.test.web.servlet.DefaultMvcResult.getAsyncResult（DefaultMvcResult.java:120）在org.springframework.test.web.servlet.request.MockMvcRequestBuilders.asyncDispatch（MockMvcRequestBuilders.java:235）在nl.bioprodict.blast.docs.PollControllerDocumentation.pollPending（PollControllerDocumentation.java:53） ...

与此相关的Spring框架测试，我发现它们似乎都使用了嘲弄它：https://github.com/spring-projects/spring-framework/blob/master/spring-web/src/test/java/org/springframework/web/context/request/async/WebAsyncManagerTimeoutTests.java

如何测试DeferredResult timeoutResult的正确处理？

Answer 1

在我的情况下，经过Spring源代码并设置超时（10000毫秒）并获得异步结果后，我就解决了它，as;

 mvcResult.getRequest().getAsyncContext().setTimeout(10000);
 mvcResult.getAsyncResult();

我的整个测试代码是;

MvcResult mvcResult = this.mockMvc.perform(
                                post("<SOME_RELATIVE_URL>")
                                .contentType(MediaType.APPLICATION_JSON)
                                .content(<JSON_DATA>))
                        ***.andExpect(request().asyncStarted())***
                            .andReturn();

***mvcResult.getRequest().getAsyncContext().setTimeout(10000);***
***mvcResult.getAsyncResult();***

this.mockMvc
    .perform(asyncDispatch(mvcResult))
    .andDo(print())
    .andExpect(status().isOk());

希望有所帮助......

Answer 2

我ran across this problem使用Spring 4.3，并设法找到一种从单元测试中触发超时回调的方法。在获得MvcResult之后和调用asyncDispatch()之前，您可以插入如下代码：

MockAsyncContext ctx = (MockAsyncContext) mvcResult.getRequest().getAsyncContext();
for (AsyncListener listener : ctx.getListeners()) {
    listener.onTimeout(null);
}

请求的异步侦听器之一将调用DeferredResult的超时回调。

因此您的单元测试将如下所示：

@Test
public void pollPending() throws Exception {
    MvcResult result = mockMvc.perform(get("/poll/{uuid}", uuidPending)).andReturn();
    MockAsyncContext ctx = (MockAsyncContext) result.getRequest().getAsyncContext();
    for (AsyncListener listener : ctx.getListeners()) {
        listener.onTimeout(null);
    }
    mockMvc.perform(asyncDispatch(result))
            .andExpect(status().isAccepted());
}

如何测试DeferredResult timeoutResult

2 个答案: