从头认识多线程-2.12 synchronized ()代码块不单可以用this，也可以用其他对象

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这一章节我们来讨论一下synchronized ()代码块的另一个用法，它不单可以用this，也可以用其他对象。

1.代码清单

package com.ray.deepintothread.ch02.topic_13;

/**
 * 
 * @author RayLee
 *
 */
public class ObjectLock {
	public static void main(String[] args) throws InterruptedException {
		MyService myService = new MyService();
		ThreadOne threadOne = new ThreadOne(myService);
		Thread thread = new Thread(threadOne);
		thread.start();
		ThreadTwo threadTwo = new ThreadTwo(myService);
		Thread thread2 = new Thread(threadTwo);
		thread2.start();
	}
}

class ThreadOne implements Runnable {

	private MyService myService;

	public ThreadOne(MyService myService) {
		this.myService = myService;
	}

	@Override
	public void run() {
		try {
			myService.updateA();
		} catch (InterruptedException e) {
			e.printStackTrace();
		}
	}
}

class ThreadTwo implements Runnable {

	private MyService myService;

	public ThreadTwo(MyService myService) {
		this.myService = myService;
	}

	@Override
	public void run() {
		try {
			myService.updateB();
		} catch (InterruptedException e) {
			e.printStackTrace();
		}
	}
}

class MyService {

	private Object object;

	public MyService() {
		object = new Object();
	}

	public void updateA() throws InterruptedException {
		synchronized (object) {
			long startTime = System.currentTimeMillis();
			System.out.println("updateA startTime:" + startTime);
			Thread.sleep(1000);
			long endTime = System.currentTimeMillis();
			System.out.println("updateA endTime:" + endTime);
		}
	}

	public void updateB() throws InterruptedException {
		synchronized (object) {
			long startTime = System.currentTimeMillis();
			System.out.println("updateB startTime:" + startTime);
			Thread.sleep(1000);
			long endTime = System.currentTimeMillis();
			System.out.println("updateB endTime:" + endTime);
		}
	}

}

updateA startTime:1462455786957
updateA endTime:1462455787958
updateB startTime:1462455787958
updateB endTime:1462455788958

2.结论

从输出可以看见，跟前面章节的代码相比，我们把synchronized ()里面的this换成一个new Object（），而且这个object不一定是object，可以是任何对象

总结：这一章节展示了synchronized ()代码块的另一个用法，它不单可以用this，也可以用其他对象。

这一章节就到这里，谢谢

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我的github：https://github.com/raylee2015/DeepIntoThread

目录：http://blog.csdn.net/raylee2007/article/details/51204573

从头认识多线程-2.12 synchronized ()代码块不单可以用this，也可以用其他对象

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原文地址：http://blog.csdn.net/raylee2007/article/details/51326584