CompletableFuture并行异步处理类使用示例

清疚 2023-10-08 10:19 29阅读 0赞

> 等待所有任务执行完, 串行执行和异步执行的高级写法:

package com.zhangxueliang.demo.springbootdemo.JUC.c_026_01_ThreadPool;
    
    import java.util.Random;
    import java.util.concurrent.CompletableFuture;
    import java.util.concurrent.TimeUnit;
    
    /**
     * @ProjectName springbootdemo_src
     * @ClassName T06_01_CompletableFuture
     * @Desicription TODO
     * @Author Zhang Xueliang
     * @Date 2019/12/5 16:13
     * @Version 1.0
     **/
    public class T06_01_CompletableFuture {
    
    
        public static void main(String[] args) {
            long start,end;
            start=System.currentTimeMillis();
            /*priceOfJD();
            priceOfTB();
            priceOfTM();*/
            CompletableFuture<Double> priceOfTM = CompletableFuture.supplyAsync(() -> priceOfTM());
            CompletableFuture<Double> priceOfJD = CompletableFuture.supplyAsync(() -> priceOfJD());
            CompletableFuture<Double> priceOfTB = CompletableFuture.supplyAsync(() -> priceOfTB());
            CompletableFuture.allOf(priceOfJD,priceOfTB,priceOfTM).join();
    
            end=System.currentTimeMillis();
            System.out.println(end-start);
        }
    
    
        private static double priceOfTM() {
            delay();
            return 1.00;
        }
    
        private static double priceOfTB() {
            delay();
            return 2.00;
        }
    
        private static double priceOfJD() {
            delay();
            return 3.00;
        }
    
        private static void delay() {
            int time = new Random().nextInt(500);
            try {
                TimeUnit.MILLISECONDS.sleep(time);
            } catch (InterruptedException e) {
                e.printStackTrace();
            }
            System.out.printf("After %s sleep!\n", time);
        }
    
    }

![20191205164600935.png][]

> Completable好玩的API:

package com.zhangxueliang.demo.springbootdemo.JUC.c_026_01_ThreadPool;
    
    import java.util.Random;
    import java.util.concurrent.CompletableFuture;
    import java.util.concurrent.TimeUnit;
    
    /**
     * @ProjectName springbootdemo_src
     * @ClassName T06_01_CompletableFuture
     * @Desicription TODO
     * @Author Zhang Xueliang
     * @Date 2019/12/5 16:13
     * @Version 1.0
     **/
    public class T06_01_CompletableFuture {
    
    
        public static void main(String[] args) {
            CompletableFuture.supplyAsync(()->priceOfJD()).thenApply(String::valueOf).thenApply(str->"price "+str).thenAccept(System.out::println);
            while (true){}
      
        }
    
    
        private static double priceOfTM() {
            delay();
            return 1.00;
        }
    
        private static double priceOfTB() {
            delay();
            return 2.00;
        }
    
        private static double priceOfJD() {
            delay();
            return 3.00;
        }
    
        private static void delay() {
            int time = new Random().nextInt(500);
            try {
                TimeUnit.MILLISECONDS.sleep(time);
            } catch (InterruptedException e) {
                e.printStackTrace();
            }
            System.out.printf("After %s sleep!\n", time);
        }
    
    }

[20191205164600935.png]: https://img-blog.csdnimg.cn/20191205164600935.png