异步回调

很像ajax

package com.luoKing.future;

import java.util.concurrent.CompletableFuture;
import java.util.concurrent.ExecutionException;

public class Demo {


    public static void main(String[] args) throws ExecutionException, InterruptedException {
//        //没有返回值的异步回调
//        CompletableFuture completableFuture =CompletableFuture.runAsync(()->{
//            System.out.println(Thread.currentThread().getName()+"->runAsync");
//        });
//
//        System.out.println("11111");
//        completableFuture.get();//获取异步执行结果


        //有返回值的异步调用
        CompletableFuture completableFuture2 =CompletableFuture.supplyAsync(()->{
            int sum = 10/0;
            return 1024;
        });
        System.out.println(completableFuture2.whenComplete((t, u) -> {
            System.out.println("t->" + t); //t输出回调正确的信息
            System.out.println("u->" + u); //u输出异常信息 java.util.concurrent.CompletionException:
        }).exceptionally((e) -> {
            System.out.println(e.getMessage());
            return 500;//当发生错误回调时，就会输出这里的返回值
        }).get());

    }

}