重学java 44.多线程 Lock锁的使用

news2025/3/15 6:29:49

昨日之深渊，今日之浅谈

—— 24.5.25

一、Lock对象的介绍和基本使用

1.概述

Lock是一个接口

2.实现类

ReentrantLock

3.方法

lock()获取锁

unlock()释放锁

4.Lock锁的使用

package S78Lock;

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

public class MyTicket implements Runnable{
    // 定义100章票
    int ticket = 100;

    // 创建lock对象
    Lock lock = new ReentrantLock();


    @Override
    public void run(){
        while(true){
            try{
                Thread.sleep(100L);

                // 获取锁
                lock.lock();
                if (ticket > 0) {
                    System.out.println(Thread.currentThread().getName() + "买了第" + ticket + "张票");
                    ticket--;
                }
            } catch (InterruptedException e) {
                throw new RuntimeException(e);
            }finally {
                // 释放锁
                lock.unlock();
            }
        }
    }
}

package S78Lock;

public class Demo217Test {
    public static void main(String[] args) {
        // new一次，分别传递到三个线程对象中去
        MyTicket myTicket = new MyTicket();
        System.out.println(myTicket);

        Thread th1= new Thread(myTicket, "赵四");
        Thread th2= new Thread(myTicket, "刘能");
        Thread th3= new Thread(myTicket, "广坤");

        th1.start();
        th2.start();
        th3.start();
    }
}

仍然是线程安全的