thread-->设置后台执行类

package thread;

import java.util.concurrent.ExecutorService;
import java.util.concurrent.Executors;
import java.util.concurrent.ThreadFactory;
import java.util.concurrent.TimeUnit;

public class Daemonromactory implements Runnable
{
    
    public void run()
    {
        try
        {
            while (true)
            {
                TimeUnit.MILLISECONDS.sleep(100);
                System.out.println(Thread.currentThread() + " : " + this);
            }
        }
        catch (InterruptedException e)
        {
            // TODO Auto-generated catch block
            e.printStackTrace();
        }
    }
    
    public static void main(String[] args)
        throws Exception
    {
        ExecutorService service = Executors.newCachedThreadPool(new DaemonThreadFactory());
        for (int i = 0; i < 10; i++)
        {
            service.execute(new Daemonromactory());
        }
        System.out.println("all daemons started");
        TimeUnit.MILLISECONDS.sleep(100);
    }
    
}

class DaemonThreadFactory implements ThreadFactory
{
    
    public Thread newThread(Runnable r)
    {
        Thread t = new Thread(r);
        t.setDaemon(true);
        return t;
    }
}

 例子2 ：由后台线程创建的线程全部都是后台线程。后台线程的存活时间取决于调用它的前台线程，如果前台线程执行完毕，后台线程执行就结束。

package thread;

import java.util.concurrent.TimeUnit;

/** 设置后台执行线程 */
public class SimpleDaemons implements Runnable
{
    public void run()
    {
        try
        {
            while (true)
            {
                TimeUnit.MILLISECONDS.sleep(100);
                System.out.println(Thread.currentThread());
            }
        }
        catch (Exception e)
        {
            System.out.println("sleep() interrupted");
        }
    }
    
    public static void main(String[] args)
        throws Exception
    {
        for (int i = 0; i < 10; i++)
        {
            Thread daemon = new Thread(new SimpleDaemons());
            daemon.setDaemon(true);// 设置为后台启动
            daemon.start();
        }
        System.out.println("all daemons started");
        
        TimeUnit.MILLISECONDS.sleep(100);// 当主程序停止时，后台程序同时被停止，可以设置睡眠时间来测试
        
    }
    
}