java CompletableFuture 异步编程工具用法1

1、测试异步调用：

static void testCompletableFuture1() throws ExecutionException, InterruptedException {// 1、无返回值的异步任务。异步线程执行RunnableCompletableFuture.runAsync(() -> System.out.println("only you"));// 2、有返回值的异步任务。执行Supplier函数并返回结果CompletableFuture<String> future = CompletableFuture.supplyAsync(() -> "3个时辰内必须找人解毒，不过老夫也可以帮忙哦");System.out.println("supplyAsync, result: " + future.get()); // 阻塞获取结果}

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2、链式调用：

static void testCompletableFuture2() throws ExecutionException, InterruptedException {System.out.println("main thread, id: " +  Thread.currentThread().getId());// 链式操作CompletableFuture<String> future = CompletableFuture.supplyAsync(() -> {System.out.println("supplyAsync thread: " + Thread.currentThread().getId());return "我行我素";});// 结果转换future = future.thenApply(s -> {System.out.println("thenApply thread: " + Thread.currentThread().getId());return s + " !!!";});// 结果消费CompletableFuture<Void> future2 = future.thenAccept(s -> {System.out.println("thenAccept thread: " + Thread.currentThread().getId());System.out.println(s);// 输出结果});}

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3、依赖其他Future任务

// thenCompose()串联多个异步任务,前一个任务结果为后一个任务的输入static void testCompletableFuture3() throws ExecutionException, InterruptedException {CompletableFuture<String> future = CompletableFuture.supplyAsync(() -> "haiyangxuanfeng");future = future.thenCompose(s -> CompletableFuture.supplyAsync(s::toUpperCase));future.thenAccept(new Consumer<String>() {@Overridepublic void accept(String s) {System.out.println(s);}}).get();}

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