Send status 200 without having to wait any return

Question

I have a GET request in my API that can be called via url. My problem is that this request is waiting for some return, even though it may take indefinitely. I would like to return a 200 status code right at the beginning of the application so that the user does not have his page blocked waiting for a response, while the rest of the code is executed normally.

My actual code look like this:

@Controller
public class APITest {

    @RequestMapping(value="test", method=RequestMethod.GET)
        public void RequestTest(
                @RequestParam(value="token", required=false) String token, 
                HttpServletRequest request, HttpServletResponse response)
                throws InterruptedException, ParseException, IOException, SQLException {

            // SOME CODE HERE

            return;
        }   
}

Is what I need possible using this method?

How about using `@Async` methods? See this [Getting Started](https://spring.io/guides/gs/async-method/) article. — wjans, May 27 '20 at 08:31
This remembers me an old [post of mine](https://stackoverflow.com/a/25402616/3545273). You should try to set the status and close the output stream of the response. — Serge Ballesta, May 27 '20 at 08:36
Thank you @SergeBallesta this worked fine for me! Exactly what I need. Despite the answer from Stephan worked as well, your method is simpler. Thank you! — pnda, May 27 '20 at 08:58

score 0 · Accepted Answer · answered May 27 '20 at 08:33

You could run the code in a different thread.

@Controller
public class APITest {

    @RequestMapping(value="test", method=RequestMethod.GET)
        public void RequestTest(
                @RequestParam(value="token", required=false) String token, 
                HttpServletRequest request, HttpServletResponse response)
                throws InterruptedException, ParseException, IOException, SQLException {

            CompletableFuture.runAsync(() -> longRunningTask());

            return;
        }   
}

The longRunningTask() will be executed in a different thread and RequestTest() will return directly with a 200.

Send status 200 without having to wait any return

1 Answers1