java死锁的简单例子有哪些

Java死锁是指两个或多个线程在执行过程中，因争夺资源而造成的一种相互等待的现象，当线程处于这种状态时，它们无法继续执行，除非其他线程释放它们正在等待的资源，下面是一个Java死锁的简单例子：

1、创建两个线程类ThreadA和ThreadB，分别继承Thread类。

class ThreadA extends Thread {
    private Object lock1;
    private Object lock2;
    public ThreadA(Object lock1, Object lock2) {
        this.lock1 = lock1;
        this.lock2 = lock2;
    }
    @Override
    public void run() {
        synchronized (lock1) {
            System.out.println("ThreadA 获取了 lock1");
            try {
                Thread.sleep(100);
            } catch (InterruptedException e) {
                e.printStackTrace();
            }
            synchronized (lock2) {
                System.out.println("ThreadA 获取了 lock2");
            }
        }
    }
}
class ThreadB extends Thread {
    private Object lock1;
    private Object lock2;
    public ThreadB(Object lock1, Object lock2) {
        this.lock1 = lock1;
        this.lock2 = lock2;
    }
    @Override
    public void run() {
        synchronized (lock1) {
            System.out.println("ThreadB 获取了 lock1");
            try {
                Thread.sleep(100);
            } catch (InterruptedException e) {
                e.printStackTrace();
            }
            synchronized (lock2) {
                System.out.println("ThreadB 获取了 lock2");
            }
        }
    }
}

2、在main方法中创建两个对象lock1和lock2，并创建两个线程threadA和threadB，分别传入这两个对象作为参数，然后启动这两个线程。

public class DeadlockExample {
    public static void main(String[] args) {
        Object lock1 = new Object();
        Object lock2 = new Object();
        Thread threadA = new ThreadA(lock1, lock2);
        Thread threadB = new ThreadB(lock1, lock2);
        threadA.start();
        threadB.start();
    }
}

3、运行程序，观察输出结果，由于线程threadA和threadB分别持有lock1和lock2的锁，且按照相同的顺序尝试获取锁，因此它们会互相等待对方释放锁，导致死锁，程序将无法继续执行。