CompletableFuture.runAsync 異步回調

CompletableFuture.runAsync 異步任務

//外派一個可能阻塞的任務，另外執行，自己先執行其他任務，后面再get回任務結果
** CompletableFuture completableFuture = CompletableFuture.supplyAsync(()->{});**

package CompleTableFutureA;

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

/**CompletableFuture.runAsync 異步任務
 * @author liu
 */
public class Demo01 {
    public static void main(String[] args) throws ExecutionException, InterruptedException {
/*//沒有返回值的runAsync 異步回調
        CompletableFuture<Void> completableFuture1 = CompletableFuture.runAsync(()->{
            try {
                TimeUnit.SECONDS.sleep(2);
            } catch (InterruptedException e) {
                e.printStackTrace();
            }
            System.out.println(Thread.currentThread().getName()+".runAsync==>void");
        });
        System.out.println("11111");
        completableFuture1.get();//獲取阻塞執行結果*/


        //有返回值的supplyAsync 異步回調
        //ajax，成功和失敗的回調
        //返回的是錯誤信息
        CompletableFuture<Integer> completableFuture = CompletableFuture.supplyAsync(() -> {
            System.out.println(Thread.currentThread().getName() + "supplyAsync=>Integer");
            //int i=10/0;
            return 200;
        });

        System.out.println(completableFuture.whenComplete((t, u) -> {
            System.out.println("t-> " + t);//正常的返回結果
            System.out.println("u-> " + u);//錯誤信息
        }).exceptionally((e) -> {
            System.out.println(e.getMessage());
            return 404;
        }).get());

    }
}