2.2.5synchronized代码间的同步性

package com.cky.bean;
 
/**
 * Created by chenkaiyang on 2017/12/6.
 */
public class ObjectService {
    public void serviceMethodA(){
        synchronized (this) {
            try {
                System.out.println("a begin time="+System.currentTimeMillis());
                Thread.sleep(2000);
                System.out.println("a end time="+System.currentTimeMillis());
            } catch (InterruptedException e) {
                e.printStackTrace();
            }
        }
 
    }
 
    public void serviceMethodB(){
        synchronized (this) {
            System.out.println("b begin time="+System.currentTimeMillis());
            System.out.println("b end time="+System.currentTimeMillis());
        }
 
    }
}

package com.cky.thread;
 
import com.cky.bean.ObjectService;
 
/**
 * Created by chenkaiyang on 2017/12/5.
 */
public class ThreadA extends Thread{
    private ObjectService service;
    public ThreadA(ObjectService service) {
        super();
        this.service = service;
    }
 
    @Override
    public void run() {
        super.run();
        service.serviceMethodA();
    }
}

package com.cky.thread;
 
import com.cky.bean.ObjectService;
 
/**
 * Created by chenkaiyang on 2017/12/5.
 */
public class ThreadB extends  Thread{
    private ObjectService service;
    public ThreadB(ObjectService service) {
        super();
        this.service = service;
    }
 
    @Override
    public void run() {
        super.run();
        service.serviceMethodB();
    }
}

package com.cky.test;
 
import com.cky.bean.ObjectService;
import com.cky.thread.ThreadA;
import com.cky.thread.ThreadB;
 
/**
 * Created by chenkaiyang on 2017/12/6.
 */
public class Test2 {
    public static void main(String[] args) {
        ObjectService objectService = new ObjectService();
        ThreadA a = new ThreadA(objectService);
        a.setName("a");
        ThreadB b = new ThreadB(objectService);
        b.setName("b");
        a.start();
        b.start();
 
    }
}

D:\it\jdk1.8\bin\java -Didea.launcher.port=7541 "-Didea.launcher.bin.path=D:\it\idea\IntelliJ IDEA 2016.3.3\bin" -Dfile.encoding=UTF-8 -classpath "D:\it\jdk1.8\jre\lib\charsets.jar;D:\it\jdk1.8\jre\lib\deploy.jar;D:\it\jdk1.8\jre\lib\ext\access-bridge-64.jar;D:\it\jdk1.8\jre\lib\ext\cldrdata.jar;D:\it\jdk1.8\jre\lib\ext\dnsns.jar;D:\it\jdk1.8\jre\lib\ext\jaccess.jar;D:\it\jdk1.8\jre\lib\ext\jfxrt.jar;D:\it\jdk1.8\jre\lib\ext\localedata.jar;D:\it\jdk1.8\jre\lib\ext\nashorn.jar;D:\it\jdk1.8\jre\lib\ext\sunec.jar;D:\it\jdk1.8\jre\lib\ext\sunjce_provider.jar;D:\it\jdk1.8\jre\lib\ext\sunmscapi.jar;D:\it\jdk1.8\jre\lib\ext\sunpkcs11.jar;D:\it\jdk1.8\jre\lib\ext\zipfs.jar;D:\it\jdk1.8\jre\lib\javaws.jar;D:\it\jdk1.8\jre\lib\jce.jar;D:\it\jdk1.8\jre\lib\jfr.jar;D:\it\jdk1.8\jre\lib\jfxswt.jar;D:\it\jdk1.8\jre\lib\jsse.jar;D:\it\jdk1.8\jre\lib\management-agent.jar;D:\it\jdk1.8\jre\lib\plugin.jar;D:\it\jdk1.8\jre\lib\resources.jar;D:\it\jdk1.8\jre\lib\rt.jar;F:\springboot\threaddemo\out\production\threaddemo;D:\it\idea\IntelliJ IDEA 2016.3.3\lib\idea_rt.jar" com.intellij.rt.execution.application.AppMain com.cky.test.Test2
a begin time=1512569404772
a end time=1512569406772
b begin time=1512569406772
b end time=1512569406772

结果分析：当一个线程访问object的一个同步代码块时，其他线程对同一个object的所有其他的同步代码块将被阻塞，这说明同步代码块使用的是对象监视