定义一个dog类

public class Dog {private String name;public String getName() {return name;}public void setName(String name) {this.name = name;}
}

定义一个同步对象锁

//同步对象锁
public class SysObject implements Runnable {private Dog dog;public SysObject(){if(dog==null){dog=new Dog();}}public void run(){Thread current=Thread.currentThread();synchronized (dog){for(int i=1;i<10;i++){System.out.println( "线程"+current.getName()+"在修改dog的名字" );dog.setName( "卡尔"+ i);System.out.println( dog.getName() );try {Thread.sleep( 1000 );}catch (InterruptedException e){e.printStackTrace();}}}}
}

测试类

public class test109 {public static void main(String[] args){SysObject sysObj=new SysObject();Thread t0=new Thread( sysObj,"歌谣" );Thread t1=new Thread( sysObj,"小白" );Thread t2=new Thread( sysObj,"小红" );t2.setPriority( Thread.MAX_PRIORITY );t2.start();t1.start();t0.start();}
}

运行结果