java多线程死锁简单实例

TestDeadLock.java:
package com.ctgu.testDeadLock;

public class TestDeadLock {

public static void main(String[] args) {
    User user = new User("大毛", "123", 22);
    User user2 = new User("二毛", "456", 44);
    new Thread1("Thread1", user, user2).start();
    new Thread2("Thread2", user, user2).start();
}

}

Thread1.java:
package com.ctgu.testDeadLock;

public class Thread1 extends Thread{

private User user;
private User user2;

public Thread1(String name, User user, User user2) {
    this.setName(name);
    this.user = user;
    this.user2 = user2;
}

@Override
public void run() {
    synchronized (user) {
        System.out.println(Thread.currentThread().getName() + " 锁定user");
        try {
            Thread.sleep(5000);
        } catch (InterruptedException e) {
            e.printStackTrace();
        }
        synchronized (user2) {
            System.out.println(Thread.currentThread().getName() + " 锁定user2");
        }
    }
}

}

Thread2.java:
package com.ctgu.testDeadLock;

public class Thread2 extends Thread{

private User user;
private User user2;

public Thread2(String name, User user, User user2) {
    this.setName(name);
    this.user = user;
    this.user2 = user2;
}

@Override
public void run() {
    synchronized (user2) {
        System.out.println(Thread.currentThread().getName() + " 锁定user2");
        try {
            Thread.sleep(5000);
        } catch (InterruptedException e) {
            e.printStackTrace();
        }
        synchronized (user) {
            System.out.println(Thread.currentThread().getName() + " 锁定user");
        }
    }
}

}

运行结果:
Thread1 锁定user
Thread2 锁定user2
此时,程序一直执行不停止,死锁现象发生