FutureTask创建Future

本文演示通过FutureTask去创建Future.

概述

　　我们通过类图去说明FutureTask,见下图所示

　　

FutureTask实例

　　下面我们通过一个代码去演示FutureTask用法，见下图所示：

　　

package com.yang.callable;

import java.util.concurrent.*;

public class FutureTaskDemo {
    public static void main(String[] args) throws ExecutionException, InterruptedException {
        ExecutorService executorService = Executors.newFixedThreadPool(2);
        FutureTask<Integer> futureTask = new FutureTask<>(new Task());
        executorService.submit(futureTask);
        System.out.println(futureTask.get());
        executorService.shutdown();
    }

    static class Task implements Callable<Integer> {
        @Override
        public Integer call() throws Exception {
            int num = 0;
            for (int i = 0; i < 10000; i++) {
                num = num + i;
            }
            return num;
        }
    }
}

　　运行结果如下：