示例代码

public class DeadLockDemo {private static Object lock1 = new Object();private static Object lock2 = new Object();public static void main(String[] args) {new Thread(() -> {synchronized (lock1) {try {System.out.println("thread1 begin");Thread.sleep(5000);} catch (InterruptedException e) {}synchronized (lock2) {System.out.println("thread1 end");}}}).start();new Thread(() -> {synchronized (lock2) {try {System.out.println("thread2 begin");Thread.sleep(5000);} catch (InterruptedException e) {}synchronized (lock1) {System.out.println("thread2 end");}}}).start();}
}

使用下面的命令输出线程信息

jstack <pid>

“Thread-1” 线程名
prio=5 优先级=5
tid=0x0000028ae51d6000 线程id
nid=0x8778 线程对应的本地线程标识nid
java.lang.Thread.State: BLOCKED 线程状态

通过输出结果，可以看到有一个线程死锁，Thread-0和Thread-1在进行资源的竞争，同时也输出了资源竞争代码所在行。