多线程ExecutorService中submit和execute区别

多线程ExecutorService中submit和execute区别

• 介绍

  submit和execute都是 ExecutorService 的方法，都是添加线程到线程池中。

• 区别 
  submit 有返回值 返回future ， execute没有

• submit 返回值 future 用处 
  可以执行cancle方法，取消执行 
  可以通过get()方法，判断是否执行成功 ==null表示执行成功

import java.util.concurrent.ExecutionException;
import java.util.concurrent.ExecutorService;
import java.util.concurrent.Executors;
import java.util.concurrent.Future;

public class ThreadPoolDemo
{

    class ThreadDemo implements Runnable
    {

        public void run()
        {
            System.err.println("hello world");
        }

    }

    public static void main(String[] args)
    {
        ExecutorService executorService = Executors.newFixedThreadPool(2);

        ThreadPoolDemo threadPoolDemo = new ThreadPoolDemo();
        for (int i = 0; i < 5; i++)
        {
            ThreadDemo threadDemo = threadPoolDemo.new ThreadDemo();
            Future future = executorService.submit(threadDemo);

            // 可以取消执行
            future.cancel(true);

            // 可以获取返回结果，如果future.get()!=null 且无异常，表示执行成功
            try
            {
                if (future.get() == null) System.out.println("执行完成");
            }
            catch (InterruptedException e)
            {
                e.printStackTrace();
            }
            catch (ExecutionException e)
            {
                e.printStackTrace();
            }
        }
    }
}
转载来源:http://blog.youkuaiyun.com/ai2713165/article/details/50466212