3、代码实现

import java.util.concurrent.locks.Condition;
import java.util.concurrent.locks.Lock;
import java.util.concurrent.locks.ReentrantLock;

//1、创建资源类，定义属性和操作方法
class ShareResource{
    //定义标志位
    private int flag=1;//1 AA 2 BB 3 CC
    //创建Lock锁
    private Lock lock=new ReentrantLock();

    //创建三个condition
    private Condition c1=lock.newCondition();
    private Condition c2=lock.newCondition();
    private Condition c3=lock.newCondition();

    //打印5次，参数第几轮
    public void print5(int loop) throws InterruptedException {
        //上锁
        lock.lock();
        try {
            //判断
            while(flag!=1){
                //等待
                c1.await();
            }
            //干活
            for (int i = 1; i <=5 ; i++) {
                System.out.println(Thread.currentThread().getName()+"::"+i+" :轮数"+loop);
            }
            //通知
            flag=2; //修改标志位
            c2.signal();    //通知BB线程
        }finally {
            //解锁
            lock.unlock();
        }
    }
    //打印10次，参数第几轮
    public void print10(int loop) throws InterruptedException {
        lock.lock();
        try {
            while(flag!=2){
                c2.await();
            }
            //干活
            for (int i = 1; i <=10 ; i++) {
                System.out.println(Thread.currentThread().getName()+"::"+i+" :轮数"+loop);
            }
            //通知
            flag=3; //修改标志位
            c3.signal();    //通知CC线程
        }finally {
            lock.unlock();
        }
    }
    //打印15次，参数第几轮
    public void print15(int loop) throws InterruptedException {
        lock.lock();
        try {
            while(flag!=3){
                c3.await();
            }
            //干活
            for (int i = 1; i <=15 ; i++) {
                System.out.println(Thread.currentThread().getName()+"::"+i+" :轮数"+loop);
            }
            //通知
            flag=1; //修改标志位
            c1.signal();    //通知CC线程
        }finally {
            lock.unlock();
        }
    }
}
public class ThreadDemo3 {
    public static void main(String[] args) {
        ShareResource shareResource=new ShareResource();
        new Thread(()->{
            for (int i = 1; i <=10 ; i++) {
                try {
                    shareResource.print5(i);
                } catch (InterruptedException e) {
                    e.printStackTrace();
                }
            }
        },"AA").start();

        new Thread(()->{
            for (int i = 1; i <=10 ; i++) {
                try {
                    shareResource.print10(i);
                } catch (InterruptedException e) {
                    e.printStackTrace();
                }
            }
        },"BB").start();

        new Thread(()->{
            for (int i = 1; i <=10 ; i++) {
                try {
                    shareResource.print15(i);
                } catch (InterruptedException e) {
                    e.printStackTrace();
                }
            }
        },"CC").start();
    }
}

从结果可以看到，三个线程一直在循环打印，总共打印了10轮。