package com.lk.B;

public class Test4 {
	private static final Object o1 = new Object();
	private static final Object o2 = new Object();
	
	private class Run1 implements Runnable{

		@Override
		public void run() {
			// TODO Auto-generated method stub
			String threadName = Thread.currentThread().getName();
			synchronized (o1) {
				try {
					Thread.sleep(1000);
				} catch (InterruptedException e) {
					// TODO Auto-generated catch block
					e.printStackTrace();
				}
				System.out.println(threadName+"进入同步块o1准备进入o2");
				synchronized (o2) {
					System.out.println(threadName+"已经进入同步块o2");
				}
			}
		}
		
	}
	
	private class Run2 implements Runnable{

		@Override
		public void run() {
			// TODO Auto-generated method stub
			String threadName = Thread.currentThread().getName();
			synchronized (o2) {
				try {
					Thread.sleep(1000);
				} catch (InterruptedException e) {
					// TODO Auto-generated catch block
					e.printStackTrace();
				}
				System.out.println(threadName+"进入同步块o2准备进入o1");
				synchronized (o1) {
					System.out.println(threadName+"已经进入同步块o1");
				}
			}
		}
		
	}

	public static void main(String[] args) {
		// TODO Auto-generated method stub
		Thread t1 = new Thread(new Test4().new Run1());
		Thread t2 = new Thread(new Test4().new Run2());
		t1.start();
		t2.start();
	}

}

　　控制台的红色按钮笔试程序并没有运行结束，因为处于死锁状态

  当程序启动后，第一个线程执行Run1类中的run方法，此时为o1加锁，然后线程休眠1s。然后第二个线程执行Run2类中的run方法，此时为o2加锁，然后线程休眠1s。此时第一个线程已经休眠结束，开始为o2加锁，而o2已经被加锁，因此发生了死锁。