java 多线程控制练习题_java常考手写代码题多线程创建控制-优快云博客

本文链接：https://blog.youkuaiyun.com/weixin_39475445/article/details/104336558

本文详细介绍了如何使用Java的Lock和Condition机制精确控制线程执行顺序，通过具体实例演示了三个线程（AA、BB、CC）按指定次数交替打印的过程，确保线程间的正确同步。

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//AA打印5次，BB打印10次，CC打印15次
//接着同上
//来10轮
根据题目需要精准控制线程，使用Lock来实现

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

class ShareThread{
    private int num =1;//A:1,B:2,C:3
    private Lock lock = new ReentrantLock();
    private Condition condition1 = lock.newCondition();
    private Condition condition2 = lock.newCondition();
    private Condition condition3 = lock.newCondition();
    public void printThread1(){
        lock.lock();
        try{
            //判断
            while(num != 1){
                condition1.await();
            }
            //干活
            for(int i = 0;i<=5;i++){
                System.out.println(Thread.currentThread().getName()+"\t"+i);
            }
            //通知
            num = 2;
            condition2.signal();
        }catch (Exception e){
            e.printStackTrace();
        }finally {
            lock.unlock();
        }
    }
    public void printThread2(){
        lock.lock();
        try{
            //判断
            while(num != 2){
                condition2.await();
            }
            //干活
            for(int i = 0;i<=10;i++){
                System.out.println(Thread.currentThread().getName()+"\t"+i);
            }
            //通知
            num = 3;
            condition3.signal();
        }catch (Exception e){
            e.printStackTrace();
        }finally {
            lock.unlock();
        }
    }
    public void printThread3(){
        lock.lock();
        try{
            //判断
            while(num != 3){
                condition3.await();
            }
            //干活
            for(int i = 0;i<=15;i++){
                System.out.println(Thread.currentThread().getName()+"\t"+i);
            }
            //通知
            num = 1;
            condition1.signal();
        }catch (Exception e){
            e.printStackTrace();
        }finally {
            lock.unlock();
        }
    }
}
public class ThreadPratice {
    public static void main(String[] args) {
        ShareThread shareThread = new ShareThread();
        new Thread(() ->{
            for(int i=1;i<=10;i++){
                shareThread.printThread1();
            }
        }).start();
        new Thread(() ->{
            for(int i=1;i<=10;i++){
                shareThread.printThread2();
            }
        }).start();
        new Thread(() ->{
            for(int i=1;i<=10;i++){
                shareThread.printThread3();
            }
        }).start();
    }
}