1 public class DeadLock {
 2     public static void main(String[] args) {
 3         MyThread m=new MyThread();
 4         /*创建两个线程*/
 5         Thread t1=new Thread(m);
 6         Thread t2=new Thread(m);
 7         /*线程开始运作*/
 8         t1.start();
 9         t2.start();
10     }
11 
12 }
13 class MyThread implements Runnable{
14     /*设立标志位，目的是让两个线程分别进入if-else的两个分支*/
15     public boolean flag=true;
16     @Override
17     public void run() {
18         // TODO Auto-generated method stub
19         if(flag){
20             /*flag一开始为真，线程t1进入if分支，然后讲flag置假，让接下来的线程进入else分支*/
21             flag=false;
22             while(true)
23                 synchronized (this) {
24                     synchronized (this.getClass()) {
25                         System.out.println(Thread.currentThread().getName()+"true");
26                         try { Thread.sleep(50); } catch (Exception e) {  e.printStackTrace();  } 
27                     }
28                 }
29         }else{
30             /*t2线程进入该分支，进入死循环*/
31             while(true)
32                 synchronized (this.getClass()) {
33                     synchronized (this) {
34                         System.out.println(Thread.currentThread().getName()+"false");
35                         try { Thread.sleep(50); } catch (Exception e) {  e.printStackTrace();  } 
36                     }
37                 }
38         }
39     }
40     

运行结果：
 1 Thread-0true
 2 Thread-0true
 3 Thread-0true
 4 Thread-0true
 5 Thread-1false
 6 Thread-0true
 7 Thread-0true
 8 Thread-0true
 9 Thread-0true
10 Thread-1false
11 Thread-1false
12 Thread-0true
13 Thread-0true
14 Thread-0true
15 Thread-0true
16 Thread-0true
17 Thread-1false