Java中读写锁-蒲公英云

Java中读写锁

傷城~ 2023-06-07 03:16 79阅读 0赞

1.读写操作必须共用一个锁对象

读线程

public class ReadLock implements Runnable {
    // 获取一个key对应的value
    public void get(String key) {
        ReentrantReadWriteLock.ReadLock readLock = WriteLock.rwl.readLock();
        readLock.lock();
        try {
            //为了演示出效果，get操作再细分如下，开始—>结束视为原子步骤
            System.out.println("正在做读的操作,key:" + key + " 开始");
            Thread.sleep(1000);
            System.out.println("正在做读的操作,key:" + key + " 结束");
        } catch (InterruptedException e) {
            e.printStackTrace();
        } finally {
            readLock.unlock();
        }
    }
    @Override
    public void run() {
        for (int key = 0; key < 5; key++) {
            get("" + key);
        }
    }
}

2.写线程

public class WriteLock implements Runnable {
    public static final ReentrantReadWriteLock rwl = new ReentrantReadWriteLock();//读写锁对象,两者必须共用一个锁对象
    // 获取一个key对应的value
    public void put(String key) {
        ReentrantReadWriteLock.WriteLock writeLock =rwl.writeLock();
        try {
            writeLock.lock();
            System.out.println("正在做写的操作,key:" + key + ",value:" + "开始.");
            Thread.sleep(1000);
            System.out.println("正在做写的操作,key:" + key + ",value:" + "结束.");
            System.out.println();
        } catch (InterruptedException e) {
            e.printStackTrace();
        } finally {
            writeLock.unlock();
        }
    }
    @Override
    public void run() {
        for (int key = 0; key < 5; key++) {
            put("" + key);
        }
    }
}

3.测试

public class LockTest {
    public static void main(String[] args) {
        ReadLock readLock=new ReadLock(); //读
        WriteLock writeLock=new WriteLock(); //写
        Thread thread1=new Thread(readLock); //读线程
        Thread thread2=new Thread(readLock); //读线程
        Thread thread3=new Thread(writeLock);//写线程
        thread1.start();//启动读
        thread2.start();//启动读
        thread3.start();//启动写
    }
}