How do I use Jetty Continuations in Dropwizard?

Question

I have a resource method that looks like this:

@Path("/helloworld")
@GET
public Response sayHello(@Context HttpServletRequest request)
        throws InterruptedException {
    Continuation c = ContinuationSupport.getContinuation(request);

    c.suspend();
    Thread.sleep(1000);
    c.resume();

    return Response.ok("hello world hard").build();
}

It seems that when I call this endpoint, dropwizard ends up calling the sayHello method in an infinite loop. Am I doing this correctly?

Answer 1

You would use the continuation like you would for any Jetty server. Something like this really contrived example:

public Response sayHello(@Context HttpServletRequest request)
        throws InterruptedException {
  Continuation c = ContinuationSupport.getContinuation(request);

  c.setTimeout(2000);
  c.suspend();

  // Do work
  System.out.println("halp");

  // End condition
  if (c.isInitial() != true) {
    c.complete();
    return Response.ok().build();
  }

  return Response.serverError().build();
}

You go into an infinite loop because you are never getting to end of the block to return the response and the continuation is continually suspending/resuming.