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(); } }