重入锁 （替换synchronized）

package com.brendan.cn.concurrent;import java.util.concurrent.locks.ReentrantLock;public class ReenterLock implements Runnable {    public static ReentrantLock lock = new ReentrantLock();    public  static  int i = 0;    @Override    public void run() {        for (int j = 0; j <10000 ; j++) {            lock.lock();            try {                i ++;                System.out.println((Thread.currentThread().getName()  +" === >  "+i));            }finally {                lock.unlock();            }        }    }    public static void main(String[] args) throws InterruptedException {        ReenterLock  rl = new ReenterLock();        Thread t1 = new Thread(rl);        Thread t2 = new Thread(rl);        t1.start();        t2.start();        t1.join();        t2.join();        System.out.println("*************"+i);    }}这里的join 指的是加入一个线程，t.join 指等待t1线程执行完后，主线程才执行重入锁的重入是指一个线程可以多次获取资源