java线程死锁代码示例

package com.ycf.study.thread;
class Sources{
	int a;
	public void setA(int x) {
		synchronized (this) {
			this.a = x;
			try {
				Thread.sleep(2000);
			}
			catch (InterruptedException e) {
				e.printStackTrace();
			}
		}
	}
}
public class DeadThreadByExtend {
	public static void main(String[] args) {
		Sources s1 = new Sources();
		Sources s2 = new Sources();
		class MyThread1 extends java.lang.Thread {
			@Override
			      public void run() {
				System.out.println("线程1开始");
				synchronized (s1) {
					System.out.println("线程1申请修改s1");
					s1.setA(20);
					System.out.println("线程1修改完成");
					System.out.println("线程1申请修改s2");
					s2.setA(10);
					System.out.println("线程1修改s2完成");
				}
				System.out.println("线程1退出并释放锁++++++++++");
			}
		}
		class MyThread2 extends java.lang.Thread {
			@Override
			      public void run() {
				System.out.println("线程2开始");
				synchronized (s2) {
					System.out.println("线程2申请修改s2");
					s2.setA(20);
					System.out.println("线程2修改s2完成");
					System.out.println("线程2申请修改s1");
					s1.setA(10);
					System.out.println("线程2修改s1完成");
				}
				System.out.println("线程2退出并释放锁++++++++++");
			}
		}
		MyThread1 mt1 = new MyThread1();
		MyThread2 mt2 = new MyThread2();
		mt1.start();
		mt2.start();
	}
}