多線程喚醒指定線程

package com.monkey1024.communication;

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

/**
 * 使用ReenTrantLock喚醒指定線程
 *
 */
public class LockTest01 {

    public static void main(String[] args) {

        Print2 p = new Print2();

        Thread t1 = new Thread(){
            public void run(){
                while(true){
                    p.print1();
                }

            }
        };

        Thread t2 = new Thread(){
            public void run(){
                while(true){
                    p.print2();
                }
            }
        };

        Thread t3 = new Thread(){
            public void run(){
                while(true){
                    p.print3();
                }
            }
        };

        t1.start();
        t2.start();
        t3.start();
    }

}

class Print2{

    //互斥鎖
    private ReentrantLock r = new ReentrantLock();
    //監視器
    private Condition c1 = r.newCondition();
    private Condition c2 = r.newCondition();
    private Condition c3 = r.newCondition();

    private int flag = 1;

    public void print1(){
        //在要開始同步的地方加上鎖
        r.lock();
        while(flag != 1){
            try {
                //讓當前線程進入等待狀態
                c1.await();
            } catch (InterruptedException e) {
                e.printStackTrace();
            }
        }

        System.out.println("monkey");
        flag = 2;
        //隨機的喚醒c2線程
        c2.signal();
        //在執行結束后釋放鎖
        r.unlock();
    }
    //wait 釋放對象鎖
    //sleep 不釋放
    //notify 不釋放
    public void print2(){
        r.lock();
        while(flag != 2){
            try {
                c2.await();
            } catch (InterruptedException e) {
                e.printStackTrace();
            }
        }

        System.out.println("1024");
        flag = 3;
        //喚醒c3線程
        c3.signal();
        r.unlock();

    }

    public void print3(){
        r.lock();
        while(flag != 3){
            try {
                c3.await();
            } catch (InterruptedException e) {
                e.printStackTrace();
            }
        }

        System.out.println("888");
        flag = 1;
        c1.signal();
        r.unlock();

    }
}