可重入读写锁ReentrantReadWriteLock的demo使用

/**
 * ReentrantReadWriteLockDemo
 */
public class ReentrantReadWriteLockDemo {
    private int i = 0;
    private int j = 0;
    private ReadWriteLock lock = new ReentrantReadWriteLock();
    Lock readLock = lock.readLock(); // 获取读锁
    Lock writeLock = lock.writeLock(); // 获取写锁
    // 由于out是执行输出操作，不涉及修改操作，因此允许多个线程同时执行out，
    // 故使用读锁进行lock
    public void out(){
        readLock.lock();
        try {
            System.out.println(Thread.currentThread().getName()+"i的值====》"+i + "j的值====》"+j);
        }finally {
            readLock.unlock();
        }
    }
    // 由于inCreate是写数据操作，因此应该互斥访问，使用写锁进行lock
    public void inCreate() {
        writeLock.lock();
        try {
            i++;
            Thread.sleep(500L);
            j++;
        } catch (InterruptedException e) {
            e.printStackTrace();
        }finally {
            writeLock.unlock();
        }
    }
    public static void main(String[] args) {
        ReentrantReadWriteLockDemo reentrantReadWriteLockDemo = new ReentrantReadWriteLockDemo();
        // 
        for (int i = 0; i < 3; i++) {
            new Thread(()->{
                reentrantReadWriteLockDemo.inCreate();
                reentrantReadWriteLockDemo.out();
            }).start();
        }
        new Thread(()->{
            reentrantReadWriteLockDemo.out();
        },"读线程").start();
        new Thread(()->{
            reentrantReadWriteLockDemo.inCreate();
        },"写线程").start();
        new Thread(()->{
            reentrantReadWriteLockDemo.out();
        },"读线程1").start();
        new Thread(()->{
            reentrantReadWriteLockDemo.out();
        },"读线程2").start();
    }
}