Java jersey glassfish (payara) 休息 : get status on running async method

Question

我正在处理这个项目，需要大量处理和时间，我希望通过对后端的 API 调用来启动该过程。

现在，我在使用 Payara 作为服务器的开发环境中拥有 Jersey 和 Jackson 以及 Maven。

我试图让用户只需在 Web 界面中按“开始”即可开始在后台处理长任务，并且 JSON 请求可以获取状态更新，直到任务完成。

这是我的(非常糟糕的)测试代码，我用它来尝试了解该过程。任务是否在所有用户之间共享并不重要，因为该项目只是一个原型(prototype)。

ExecutorService task = Executors
        .newCachedThreadPool(new ThreadFactoryBuilder().setNameFormat("long-running-resource-executor-%d")
                .setUncaughtExceptionHandler(new JerseyProcessingUncaughtExceptionHandler()).build());

AsyncResponse asyncBla;

@GET
@Path("/expensive")
public void getExpensive(@Suspended final AsyncResponse async) {

    asyncBla = async;

    task.submit(new Runnable() {

        @Override
        public void run() {
            try {
                Thread.sleep(10000);
                System.out.println("Ba-boop");
            } catch (InterruptedException e) {
                System.out.println("barp");
            }
            // async.resume("Started");

        }

    });

    async.resume("Started");
}

@GET
@Path("/expensive/status")
public String getExpensiveStatus() {

    if (asyncBla == null)
        return "Nope.";

    return asyncBla.isDone();
}

Answer 1

您可以尝试以下方法:

@Singleton
@Path("expensive-task")
public class ExpensiveTaskResource {

    private ExecutorService executor;

    private Future<String> futureResult;

    @PostConstruct
    public void onCreate() {
        this.executor = Executors.newSingleThreadExecutor();
    }

    @POST
    public Response startTask() {
        futureResult = executor.submit(new ExpensiveTask());
        return Response.status(Status.ACCEPTED).build();
    }

    @GET
    public Response getResult() throws ExecutionException, InterruptedException {
        if (futureResult != null && futureResult.isDone()) {
            return Response.status(Status.OK).entity(futureResult.get()).build();
        } else {
            return Response.status(Status.FORBIDDEN).entity("Try later").build();
        }
    }

    @PreDestroy
    public void onDestroy() {
        this.executor.shutdownNow();
    }
}

public class ExpensiveTask implements Callable<String> {

    @Override
    public String call() throws Exception {

        try {
            Thread.sleep(10000);
        } catch (InterruptedException e) {
            e.printStackTrace();
        }

        return "Task completed";
    }
}