package com.xinwei.order.entity;

import java.util.concurrent.ExecutorService;

import java.util.concurrent.Executors;

import java.util.concurrent.Future;  

public class CallableTest {  

    public static void main(String[] args) {

        //创建线程池

        ExecutorService es = Executors.newSingleThreadExecutor();

        //创建Callable对象任务

        CallableDemo calTask=new CallableDemo();

        //提交任务并获取执行结果

        Future<Integer> future =es.submit(calTask);

        //关闭线程池

        es.shutdown();

        try {

            Thread.sleep(2000);

        System.out.println("主线程在执行其他任务");  

        if(future.get()!=null){

            //输出获取到的结果

            System.out.println("future.get()-->"+future.get());

        }else{

            //输出获取到的结果

            System.out.println("future.get()未获取到结果");

        }  

        } catch (Exception e) {

            e.printStackTrace();

        }

        System.out.println("主线程在执行完成");

    }

}

package com.xinwei.order.entity;

import java.util.concurrent.ExecutorService;

import java.util.concurrent.Executors;

import java.util.concurrent.FutureTask;

public class eeeee {  

    public static void main(String[] args) {

        //创建线程池

        ExecutorService es = Executors.newSingleThreadExecutor();

        //创建Callable对象任务

        CallableDemo calTask=new CallableDemo();

        //创建FutureTask

        FutureTask<Integer> futureTask=new FutureTask<>(calTask);

        //执行任务

        es.submit(futureTask);

        //关闭线程池

        es.shutdown();

        try {

            Thread.sleep();

        System.out.println("主线程在执行其他任务");  

        if(futureTask.get()!=null){

            //输出获取到的结果

            System.out.println("futureTask.get()-->"+futureTask.get());

        }else{

            //输出获取到的结果

            System.out.println("futureTask.get()未获取到结果");

        }  

        } catch (Exception e) {

            e.printStackTrace();

        }

        System.out.println("主线程在执行完成");

    }

} 

import java.util.concurrent.Callable;  

public class CallableDemo implements Callable<Integer> {  

    private int sum;

    @Override

    public Integer call() throws Exception {

        System.out.println("Callable子线程开始计算啦！");

        Thread.sleep();  

        for(int i= ;i<;i++){

            sum=sum+i;

        }

        System.out.println("Callable子线程计算结束！");

        return sum;

    }

}