1 //寫一個死鎖程序
 2 public class DeadLock {
 3      //主程序執行
 4      public static void main(String[] args) {
 5           Thread thread1 = new Thread(new MyThread(true));
 6           Thread thread2 = new
 
 Thread(new MyThread(true));
 7           thread1.start();
 8           thread1.start();
 9           thread2.start();
10      }
11 }
12 class MyThread implements Runnable{
13      private boolean flag;
14      //標記，用來分割線程執行部分
15      public MyThread(boolean flag) {
16           this.flag = flag;
17      }
 
18      @Override
19      public void run() {
20           if (flag) {
21                //線程1擁有鎖1而需要鎖2
22               synchronized(MyLock.object1) {
23                    System.out.println("鎖1");
24                    synchronized(MyLock.object2) {
25                         System.out.println("鎖2");
 
26                    }
27               }
28           }else {
29                //線程2擁有鎖2而需要鎖1
30               synchronized(MyLock.object2) {
31                    System.out.println("鎖2");
32                    synchronized(MyLock.object1) {
33                         System.out.println("鎖1");
34                    }
35               }
36           }
37 
38      }
39 }
40 class MyLock{
41      //創建兩個顯式的鎖
42      static Object object1 = new Object();
43      static Object object2 = new Object();
44 }

線程死鎖