交替打印线程-基于等待唤醒机制

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

/**
 * @date: 2018/8/16
 * @description: 交替打印ABC三个线程，其中A先打印5次，然后B打印10次，C打印15次，一共进行20轮打印
 * 这里使用等待唤醒机制
 */
public class AlternateThread {

    private int number = 1;
    private Lock lock = new ReentrantLock();
    private Condition condition1 = lock.newCondition();
    private Condition condition2 = lock.newCondition();
    private Condition condition3 = lock.newCondition();

    public void loopA(int loopNum) throws InterruptedException {//参数loopNum表示第几轮打印，一共要打印20轮


        lock.lock();
        try{
            //1.判断
            while(number != 1){
                condition1.await();
            }

            //2.执行线程A代码
            for(int i = 1; i <= 5; i++){
                System.out.println("线程"+Thread.currentThread().getName() + "第" + loopNum + "轮打印");
            }

            //3.通知线程B
            number = 2;
            condition2.signal();
        }finally{
            lock.unlock();
        }

    }

    public void loopB(int loopNum) throws InterruptedException {//参数loopNum表示第几轮打印，一共要打印20轮


        lock.lock();
        try{
            //1.判断
            while(number != 2){
                condition2.await();
            }

            //2.执行线程A代码
            for(int i = 1; i <= 10; i++){
                System.out.println("线程"+Thread.currentThread().getName() + "第" + loopNum + "轮打印");
            }

            //3.通知线程C
            number = 3;
            condition3.signal();
        }finally{
            lock.unlock();
        }

    }

    public void loopC(int loopNum) throws InterruptedException {//参数loopNum表示第几轮打印，一共要打印20轮


        lock.lock();
        try{
            //1.判断
            while(number != 3){
                condition3.await();
            }

            //2.执行线程A代码
            for(int i = 1; i <= 15; i++){
                System.out.println("线程"+Thread.currentThread().getName() + "第" + loopNum + "轮打印");
            }
            System.out.println();//每执行完一轮ABC的打印，换行进行下一轮

            //3.通知线程A
            number = 1;
            condition1.signal();
        }finally{
            lock.unlock();
        }

    }

    public static void main(String[] args) {
        AlternateThread at = new AlternateThread();

        new Thread(new Runnable() {
            @Override
            public void run() {

                for(int i = 1 ;i <= 20; i++){
                    try {
                        at.loopA(i);
                    } catch (InterruptedException e) {
                        e.printStackTrace();
                    }
                }
            }
        },"A").start();

        new Thread(new Runnable() {
            @Override
            public void run() {

                for(int i = 1 ;i <= 20; i++){
                    try {
                        at.loopB(i);
                    } catch (InterruptedException e) {
                        e.printStackTrace();
                    }
                }
            }
        },"B").start();

        new Thread(new Runnable() {
            @Override
            public void run() {

                for(int i = 1 ;i <= 20; i++){
                    try {
                        at.loopC(i);
                    } catch (InterruptedException e) {
                        e.printStackTrace();
                    }
                }
            }
        },"C").start();
    }
}

运行结果