java一个多线程的经典例子

import java.io.*;
//多线程编程 
public class MultiThread   
{ 
public static void main(String args[]) 
{ 
System.out.println("我是主线程!"); 
//下面创建线程实例thread1 
ThreadUseExtends thread1=new ThreadUseExtends(); 
//创建thread2时以实现了Runnable接口的THhreadUseRunnable类实例为参数 
Thread thread2=new Thread(new ThreadUseRunnable(),"SecondThread"); 
thread1.start();//启动线程thread1使之处于就绪状态 
//thread1.setPriority(6);//设置thread1的优先级为6 
//优先级将决定cpu空出时，处于就绪状态的线程谁先占领cpu开始运行 
//优先级范围1到10,MIN_PRIORITY,MAX_PRIORITY,NORM_PAIORITY 
//新线程继承创建她的父线程优先级,父线程通常有普通优先级即5NORM_PRIORITY 
System.out.println("主线程将挂起7秒!"); 
try 
{ 
Thread.sleep(7000);//主线程挂起7秒 
} 
catch (InterruptedException e) 
{ 
return; 
} 
System.out.println("又回到了主线程!"); 
if(thread1.isAlive()) 
{   
thread1.stop();//如果thread1还存在则杀掉他 
System.out.println("thread1休眠过长,主线程杀掉了thread1!"); 
} 
else 
System.out.println("主线程没发现thread1,thread1已醒顺序执行结束了!"); 
thread2.start();//启动thread2 
System.out.println("主线程又将挂起7秒!"); 
try 
{ 
Thread.sleep(7000);//主线程挂起7秒 
} 
catch (InterruptedException e) 
{ 
return; 
} 
System.out.println("又回到了主线程!"); 
if(thread2.isAlive()) 
{   
thread2.stop();//如果thread2还存在则杀掉他 
System.out.println("thread2休眠过长，主线程杀掉了thread2!"); 
} 
else 
System.out.println("主线程没发现thread2,thread2已醒顺序执行结束了!"); 
System.out.println("程序结束按任意键继续!"); 
try 
{ 
System.in.read(); 
} 
catch (IOException e) 
{ 
System.out.println(e.toString()); 
}
}//main 
}/