java - 在超时时更改 deferredResult HTTP 状态代码

Question

我在 Spring MVC 上使用 deferredResult，但是使用这段代码，超时仍然将 HTTP 代码 503 发送回客户端。

future.onCompletion(new Runnable() {
    @Override
    public void run() {

        if(future.isSetOrExpired()){
            response.setStatus(HttpServletResponse.SC_NO_CONTENT);
        }
    }
});

知道还可以尝试什么吗？

Answer 1

我遇到了同样的问题。我的 Spring MVC Controller 方法最初返回 DeferredResult<Object> ，但后来我意识到我想控制 HTTP 状态代码。我在这里找到了答案:

https://www.jayway.com/2014/09/09/asynchronous-spring-service/

@RequestMapping("/async")
DeferredResult<ResponseEntity<?>> async(@RequestParam("q") String query) {

    DeferredResult<ResponseEntity<?>> deferredResult = new DeferredResult<>();
    ListenableFuture<RepoListDto> repositoryListDto = repoListService.search(query);
    
    repositoryListDto.addCallback(
            new ListenableFutureCallback<RepoListDto>() {
                @Override
                public void onSuccess(RepoListDto result) {
                    ResponseEntity<RepoListDto> responseEntity = 
                        new ResponseEntity<>(result, HttpStatus.OK);
                    deferredResult.setResult(responseEntity);
                }

                @Override
                public void onFailure(Throwable t) {
                    log.error("Failed to fetch result from remote service", t);
                    ResponseEntity<Void> responseEntity = 
                        new ResponseEntity<>(HttpStatus.SERVICE_UNAVAILABLE);
                    deferredResult.setResult(responseEntity);
                }
            }
    );
    
    return deferredResult;
}

只需使用 DeferredResult<ResponseEntity>您可以在 ResponseEntity 中同时设置响应和 Http 响应代码.