JUC并发编程ReadWriteLock(九)

package com.xizi.readWrite;

import java.util.HashMap;
import java.util.Map;
import java.util.concurrent.locks.ReadWriteLock;
import java.util.concurrent.locks.ReentrantLock;
import java.util.concurrent.locks.ReentrantReadWriteLock;

/**
 * 独占锁（写锁）一次只能被一个线程占有
 * 共享锁（读锁）多个线程可以同时占有
 */


public class ReadWriteLockdemo {
    public static void main(String[] args) {
        MyCacheLock myCache = new MyCacheLock();

        for (int i = 1; i <= 5; i++) {
            final int temp = i;
            new Thread(() -> {
                myCache.put(temp + "", temp + "");
            }, String.valueOf(i)).start();
        }
        for (int i = 1; i <= 5; i++) {
            final int temp = i;
            new Thread(() -> {
                myCache.get(temp+"");
            }, String.valueOf(i)).start();
        }

    }


}
//加锁的
class MyCacheLock{
    private volatile Map<String, Object> map = new HashMap<>();
    //读写锁：更加细粒度的控制

    private ReadWriteLock readWriteLock=new ReentrantReadWriteLock();
    //存 写 只希望同时只有一个线程写
    public void put(String key, Object value) {
        readWriteLock.writeLock().lock();
        try {
            System.out.println(Thread.currentThread().getName() + "写入" + key);
            map.put(key, value);
            System.out.println(Thread.currentThread().getName() + "写入OK");
        } catch (Exception e) {
            e.printStackTrace();
        } finally {
            readWriteLock.writeLock().unlock();
        }
    }

    //取 读  所有人都可以读
    public void get(String key) {
        readWriteLock.readLock().lock();
        try {
            System.out.println(Thread.currentThread().getName() + "读取" + key);
            Object o = map.get(key);
            System.out.println(Thread.currentThread().getName() + "读取OK");
        } catch (Exception e) {
            e.printStackTrace();
        } finally {
            readWriteLock.readLock().unlock();
        }
    }


}


//自定义缓冲
class MyCache {
    private volatile Map<String, Object> map = new HashMap<>();

    //存 写
    public void put(String key, Object value) {
        System.out.println(Thread.currentThread().getName() + "写入" + key);
        map.put(key, value);
        System.out.println(Thread.currentThread().getName() + "写入OK");
    }

    //取 读
    public void get(String key) {
        System.out.println(Thread.currentThread().getName() + "读取" + key);
        Object o = map.get(key);
        System.out.println(Thread.currentThread().getName() + "读取OK");
    }


}