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<>异步回调
Future 设计的初衷：对将来的某个时间的结果进行建模
代码示例
package com.future; import java.util.concurrent.CompletableFuture; import java.
util.concurrent.ExecutionException; import java.util.concurrent.Future; import
java.util.concurrent.TimeUnit; /** * * 异步调用:Ajax * //异步执行 * //成功回调 * //失败回调 * *
*/ public class Demo01 { public static void main(String[] args) throws
ExecutionException, InterruptedException { //发起一个请求 Void 是void 包装类 //没有返回值的
runAsync 异步回调 // CompletableFuture<Void> completableFuture =
CompletableFuture.runAsync(()->{ // try { // TimeUnit.SECONDS.sleep(2); // }
catch (InterruptedException e) { // e.printStackTrace(); // } //
System.out.println(Thread.currentThread().getName()+"runAsync"); // }); //
System.out.println("1111"); // completableFuture.get();//获取阻塞执行结果
//有返回值的异步回调,Supplier 供给型接口 ,无入参，有返回值！ // ajax,成功和失败回调 // 失败是返回的错误信息
CompletableFuture<Integer> completableFuture1 = CompletableFuture.supplyAsync(()
-> { System.out.println(Thread.currentThread().getName()+"supplyAsync=>Integer")
; int i =10/0; return 1024; }); System.out.println(completableFuture1.
whenComplete((t, u) -> { System.out.println("t=>" + t);// 正常的返回结果 System.out.
println("u=>" + u);// 错误信息：java.util.concurrent.CompletionException }).
exceptionally((t) -> { System.out.println(t.getMessage()); return 233;
//可以获得到错误的返回结果 }).get()); /** * 一般业务返回编码 * success Code 200 * error Code 404
500 */ } }
输出结果：
ForkJoinPool.commonPool-worker-1supplyAsync=>Integer
t=>null
u=>java.util.concurrent.CompletionException: java.lang.ArithmeticException: /
by zero
java.lang.ArithmeticException: / by zero
233