springboot2.x连接zookeeper

浅浅的花香味﹌ 2023-07-19 12:15 8阅读 0赞

### 1、引入相关依赖 ###

<properties>
            <java.version>1.8</java.version>
            <lombok.version>1.18.12</lombok.version>
            <zookeeper.version>3.6.0</zookeeper.version>
        </properties>
    
        <dependencies>
            <dependency>
                <groupId>org.springframework.boot</groupId>
                <artifactId>spring-boot-starter-web</artifactId>
            </dependency>
    
            <dependency>
                <groupId>org.apache.zookeeper</groupId>
                <artifactId>zookeeper</artifactId>
                <version>${ zookeeper.version}</version>
            </dependency>
    
            <dependency>
                <groupId>org.projectlombok</groupId>
                <artifactId>lombok</artifactId>
                <version>${ lombok.version}</version>
            </dependency>
        </dependencies>

### 2、连接配置 ###

@Configuration
    public class ZookeeperConfig { 
        private static final Logger logger = LoggerFactory.getLogger(ZookeeperConfig.class);
    
        @Value("${zookeeper.address}")
        private    String connectString;
    
        @Value("${zookeeper.timeout}")
        private  int timeout;
    
    
        @Bean(name = "zkClient")
        public ZooKeeper zkClient(){ 
            ZooKeeper zooKeeper=null;
            try { 
                final CountDownLatch countDownLatch = new CountDownLatch(1);
                //连接成功后，会回调watcher监听，此连接操作是异步的，执行完new语句后，直接调用后续代码
                zooKeeper = new ZooKeeper(connectString, timeout, new Watcher() { 
                    @Override
                    public void process(WatchedEvent event) { 
                        logger.info("receive event:" + event.toString());
                        if(Event.KeeperState.SyncConnected==event.getState()){ 
                            //如果收到了服务端的响应事件,连接成功
                            countDownLatch.countDown();
                        }
                    }
                });
                countDownLatch.await();
                logger.info("【初始化ZooKeeper连接状态....】={}",zooKeeper.getState());
    
            }catch (Exception e){ 
                logger.error("初始化ZooKeeper连接异常....】={}",e);
            }
            return  zooKeeper;
        }
    
    }

### 3、测试zookeeper的api ###

@Slf4j
    @Component
    public class ZnodeTest implements CommandLineRunner { 
    
        @Autowired
        private ZooKeeper zkClient;
    
        @Override
        public void run(String... args) throws Exception { 
            List<String> children = zkClient.getChildren("/test1", new CustomWatcher());
            log.info("children: "+ children);
            if(!ObjectUtils.isEmpty(children)){ 
                for (int i = 0; i < children.size(); i++) { 
                    byte[] data = zkClient.getData("/test1/" + children.get(i), false, null);
                    if (data != null) { 
                        log.info("get child "+"/test1/"+children.get(i)+":"+new String(data));
                    }else{ 
                        log.info("get child "+"/test1/"+children.get(i)+":"+null);
                    }
    
                }
    
            }
        }
    }
    
    @Slf4j
    public class CustomWatcher implements Watcher { 
    
        @Override
        public void process(WatchedEvent watchedEvent) { 
            log.info(watchedEvent.toString());
        }
    }

![在这里插入图片描述][20200331013440526.png]  
Zookeeper中还有创建znode、删除znode、判断是否存在等api，就不一个一个去试了。

### 4、Apache Curator ###

连接zookeeper的java客户端还有一种叫curator。  
增加依赖

<dependency>
                <groupId>org.apache.curator</groupId>
                <artifactId>curator-recipes</artifactId>
                <version>${ curator.version}</version>
            </dependency>
    
            <dependency>
                <groupId>org.apache.curator</groupId>
                <artifactId>curator-framework</artifactId>
                <version>${ curator.version}</version>
            </dependency>

properties中增加

<curator.version>4.3.0</curator.version>

curator方式配置连接

@Configuration
    public class CuratorConfiguration { 
    
        @Value("${curator.retryCount}")
        private int retryCount;
    
        @Value("${curator.elapsedTimeMs}")
        private int elapsedTimeMs;
    
        @Value("${curator.connectString}")
        private String connectString;
    
        @Value("${curator.sessionTimeoutMs}")
        private int sessionTimeoutMs;
    
        @Value("${curator.connectionTimeoutMs}")
        private int connectionTimeoutMs;
    
        @Bean(initMethod = "start")
        public CuratorFramework curatorFramework() { 
            return CuratorFrameworkFactory.newClient(
                    connectString,
                    sessionTimeoutMs,
                    connectionTimeoutMs,
                    new RetryNTimes(retryCount, elapsedTimeMs));
        }
    }

application.properties中增加

#重试次数
    curator.retryCount=5
    #重试间隔时间
    curator.elapsedTimeMs=5000
    # zookeeper 地址
    curator.connectString=127.0.0.1:2181
    # session超时时间
    curator.sessionTimeoutMs=60000
    # 连接超时时间
    curator.connectionTimeoutMs=5000

测试API

@Slf4j
    @Component
    public class CuratorZnodeTest implements CommandLineRunner { 
    
        @Autowired
        private CuratorFramework zkClient;
    
        @Override
        public void run(String... args) throws Exception { 
            GetChildrenBuilder children = zkClient.getChildren();
            log.info("get children by Curator:"+children.forPath("/test1"));
        }
    }

![在这里插入图片描述][2020033101591749.png]

### 5、Java客户端的选择 ###

[Zookeeper原生Java API、ZKClient和Apache Curator 区别对比][Zookeeper_Java API_ZKClient_Apache Curator]

### 参考 ###

[SpringBoot集成Zookeeper][SpringBoot_Zookeeper]  
[缓存架构SpringBoot集成Curator实现zookeeper分布式锁][SpringBoot_Curator_zookeeper]

[20200331013440526.png]: /images/20230528/bbb61b6c55b340f69d0fa35415b1bd18.png
[2020033101591749.png]: /images/20230528/25317d8aa22c44778ab2a7841917b76f.png
[Zookeeper_Java API_ZKClient_Apache Curator]: https://blog.csdn.net/l18848956739/article/details/99693299
[SpringBoot_Zookeeper]: https://blog.csdn.net/u010391342/article/details/100404588?depth_1-utm_source=distribute.pc_relevant.none-task&utm_source=distribute.pc_relevant.none-task
[SpringBoot_Curator_zookeeper]: https://blog.csdn.net/zhuguanghalo/article/details/83278579