1、setDeamon

设置线程为后台运行的函数

public class SetDaemon
{
	public static void main(String[] args) throws InterruptedException
	{
		Thread tt=new Thread(new ThreadTest());
		tt.setDaemon(true);						//设置程序为后台运行
		tt.start();
		Thread.sleep(3);
	}
}

class ThreadTest implements Runnable
{
	public void run()
	{
		while(true)
		{
			System.out.println(Thread.currentThread().getName()+" is running...");	
		}

	}
}

可见当父线程后台运行的线程自动结束。< http://www.2cto.com/kf/ware/vc/" target="_blank" class="keylink">vcD4KPGgxPjKhompvaW48L2gxPgo8cD7Hv9bGQ1BV1rTQ0MSzuPbP37PMPC9wPgo8cD48cHJlIGNsYXNzPQ=="brush:java;">public class SetDaemon { public static void main(String[] args) throws InterruptedException { Thread tt=new Thread(new ThreadTest()); tt.start(); for(int i=0;i<10;i++) { if(i==5) { tt.join(); } System.out.println(Thread.currentThread().getName()+i+" is running..."); } } } class ThreadTest implements Runnable { public void run() { for(int i=0;i<5;i++) { System.out.println(Thread.currentThread().getName()+i+" is running..."); } } }

3、interrupt

public class SetDaemon
{
	public static void main(String[] args) throws InterruptedException
	{
		Thread tt=new Thread(new ThreadTest());
		tt.start();
		Thread.sleep(2000);
		System.out.println("The subthread is interupted in the main thread.");
		tt.interrupt();
		tt.join();
		System.out.println("The main thread is over.");
	}
}

class ThreadTest implements Runnable
{
	public void run()
	{
		try
		{
			System.out.println("The subthread is sleeping...");
			Thread.sleep(200000);
		}
		catch(Exception e)
		{
			e.printStackTrace();
			System.out.println("The subthread is interupted.");
			return;
		}
		System.out.println("The subthread is over.");
	}
}

注意：这里的线程中断和通常所讲的硬件中断并不是同一个概念，硬件中断是...（这个就不要讲啦），这里的中断可以理解成线程的状态被设置成了中断状态（即挂起了一个小旗，告诉其它线程‘哥处于中断状态’，禁止某些操作），此时执行某些函数会触发异常，被中断的线程进入到异常处理代码段。

请仔细体会以下代码：

public class SetDaemon
{
	public static void main(String[] args) throws InterruptedException
	{
		Thread tt=new Thread(new ThreadTest());
		tt.start();
		Thread.sleep(5);
		System.out.println("The subthread is interupted in the main thread.");
		tt.interrupt();
		tt.join();
		System.out.println("The main thread is over.");
	}
}

class ThreadTest implements Runnable
{
	public void run()
	{
		try
		{
			while(true)
			{
				System.out.println(Thread.currentThread().getName()+" is running...");
				Thread.sleep(1);
			}
		}
		catch(Exception e)
		{
			e.printStackTrace();
			System.out.println("The subthread is interupted.");
			return;
		}
		//System.out.println("The subthread is over.");
	}
}