多线程-异步处理的三种方法(jdk7以前,Guava,Jdk1.8)

最新推荐文章于 2022-05-17 21:23:28 发布

原创最新推荐文章于 2022-05-17 21:23:28 发布 · 2.3k 阅读

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CC 4.0 BY-SA版权

博客展示了Java中异步任务处理的示例代码。使用了ExecutorService创建线程池，分别演示了JDK原生、Guava以及JDK 1.8的CompletableFuture方式来处理异步任务，包括主动获取结果和通过回调获取结果。

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public class ListenableFutureExample {
    public static void main(String[] args) throws ExecutionException, InterruptedException {
        ExecutorService service = Executors.newFixedThreadPool(2);
        ///执行结束,这个需要主动去拿,是阻塞的数据
        getIdirect(service);
        //通过回调去拿数据
        getCallBack(service);
        getJava8(service);
    }

    //jdk1.8  ForkJoin是任务的分发处理
    private static void getJava8(ExecutorService service) {
        //默认使用的是ForkJoinPool,如果不传线程池的话
        CompletableFuture<Integer> future = CompletableFuture.supplyAsync(() -> {
            try {
                TimeUnit.SECONDS.sleep(5);
            } catch (InterruptedException e) {
                e.printStackTrace();
            }
            return 100;
        }, service).whenComplete((v, t) -> System.out.println(v));
        //V --->返回的结果
        //t--->可能出现的异常
//        future.whenComplete((v, t) ->)
    }

    //Guava
    private static void getCallBack(ExecutorService service) {

        ListeningExecutorService listeningExecutorService = MoreExecutors.listeningDecorator(service);
        ListenableFuture<Integer> future = listeningExecutorService.submit(() -> {
            try {
                TimeUnit.SECONDS.sleep(5);
            } catch (InterruptedException e) {
                e.printStackTrace();
            }
            return 100;
        });
        //runnable--->DB
        future.addListener(() -> {
        }, service);

        //CallAble处理
        Futures.addCallback(future, new MyCallBack(), service);
        System.out.println("=======================");
    }

    //回调处理
    static class MyCallBack implements FutureCallback<Integer> {

        @Override
        public void onSuccess(Integer result) {
            System.out.println("I  am finish the result is " + result);
        }

        @Override
        public void onFailure(Throwable throwable) {
            throwable.printStackTrace();
        }
    }

    //Jdk
    public static Integer getIdirect(ExecutorService service) throws ExecutionException, InterruptedException {
        Future<Integer> future = service.submit(() -> {
            try {
                TimeUnit.SECONDS.sleep(5);
            } catch (InterruptedException e) {
                e.printStackTrace();
            }
            return 10;
        });
        Integer result = future.get();
        System.out.println(result);
        return result;//执行结束,这个需要主动去拿,那么怎么通过回调去拿
    }
}