Zookeeper Curator 框架实现分布式锁

官方文档：https://curator.apache.org/index.html

依赖

    org.apache.zookeeper
    zookeeper
    3.5.7


    org.apache.curator
    curator-framework
    4.3.0


    org.apache.curator
    curator-recipes
    4.3.0


    org.apache.curator
    curator-client
    4.3.0

案例

package com.syf.case3;

import org.apache.curator.framework.CuratorFramework;
import org.apache.curator.framework.CuratorFrameworkFactory;
import org.apache.curator.framework.recipes.locks.InterProcessMutex;
import org.apache.curator.retry.ExponentialBackoffRetry;

public class CuratorLockTest {
    public static void main(String[] args) {

        // 创建分布式锁1
        InterProcessMutex lock1 = new InterProcessMutex(getCuratorFramework(), "/locks");
        // 创建分布式锁2
        InterProcessMutex lock2 = new InterProcessMutex(getCuratorFramework(), "/locks");
        new Thread(new Runnable() {
            @Override
            public void run() {

                try {
                    lock1.acquire();
                    System.out.println("线程1 获取到锁");

                    lock1.acquire();
                    System.out.println("线程1 再次获取到锁");

                    Thread.sleep(5 * 1000);

                    lock1.release();
                    System.out.println("线程1 释放锁");
                    Thread.sleep(5 * 1000);
                    lock1.release();
                    System.out.println("线程1 再次释放锁");
                } catch (Exception e) {
                    e.printStackTrace();
                }
            }
        }).start();

        new Thread(new Runnable() {
            @Override
            public void run() {

                try {
                    lock2.acquire();
                    System.out.println("线程2 获取到锁");

                    lock2.acquire();
                    System.out.println("线程2 再次获取到锁");

                    Thread.sleep(5 * 1000);

                    lock2.release();
                    System.out.println("线程2 释放锁");
                    Thread.sleep(5 * 1000);
                    lock2.release();
                    System.out.println("线程2 再次释放锁");
                } catch (Exception e) {
                    e.printStackTrace();
                }
            }
        }).start();
    }

    private static CuratorFramework getCuratorFramework() {

        ExponentialBackoffRetry policy = new ExponentialBackoffRetry(3000, 3);

        CuratorFramework client = CuratorFrameworkFactory.builder().connectString("hadoop102:2181,hadoop103:2181,hadoop104:2181")
                .connectionTimeoutMs(2000)
                .sessionTimeoutMs(2000)
                .retryPolicy(policy).build();
        // 启动客户端
        client.start();
        System.out.println("zookeeper 启动成功");
        return client;
    }
}