CompletableFutureCompletableFuture测试runAsync()方法调用CompletableFuture.join()/get()方法阻塞主线程

Posted 2021-02-28 july-sunny

问题

　　CompletableFuture.runAsync() 返回 CompletableFuture<Void>对象，调用CompletableFuture.allOf(f1,f2).join() 是否能够阻塞主线程

结论

    public static void main(String[] args) {
        CompletableFuture<Void> f1 = CompletableFuture.runAsync(() -> {
            try {
                Thread.sleep(2000);
            } catch (InterruptedException e) {
                e.printStackTrace();
            }
            System.out.println("第一个异步任务");
        });

        CompletableFuture<Void> f2 = CompletableFuture.runAsync(() -> {
            try {
                Thread.sleep(2000);
            } catch (InterruptedException e) {
                e.printStackTrace();
            }
            System.out.println("第二个异步任务");
        });
        CompletableFuture.allOf(f1,f2).join();
        System.out.println("CompletableFuture Test runAsync");
    }

　　CompletableFuture.runAsync() 返回 CompletableFuture<Void>对象，调用CompletableFuture.allOf(f1,f2).join() 可以阻塞主线程