testthread2.java

自己做的一个QQ聊天系统

package test.thread;

public class TestThread2 {
	static int i = 200; 
	static Object lock = new Object();
	public static void main(String[] args) {
		// TODO Auto-generated method stub
		Thread add = new AddThread();
		Thread sub = new SubThread();
        add.start();
        sub.start();
        try{
        	 Thread.sleep(6000);
        }catch(InterruptedException e){
        	e.printStackTrace();
        }
         System.out.println("i =" + i);
	}

}
class AddThread extends Thread{
	public void run(){
		for(int j=0;j<=100;j++){
			try{
				 Thread.sleep(50);
			}catch(InterruptedException e){
				e.printStackTrace();
			}
			synchronized(TestThread2.lock){
				TestThread2.i = TestThread2.i + 1;
			}
			System.out.println("add:"+TestThread2.i);
		}
	}
}
class SubThread extends Thread{
	public void run(){
		for(int j=0;j<=100;j++){
			try{
				Thread.sleep(50);
			}catch (InterruptedException e){
				e.printStackTrace();
			}
			synchronized(TestThread2.lock){
				TestThread2.i = TestThread2.i - 1;
			}
			System.out.println("sub:" + TestThread2.i);
		}
	}
}