springboot2.x connection zookeeper

1, the introduction of its dependencies

    <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, connection configuration

@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, the test zookeeper's 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());
    }
}

Here Insert Picture Description
Zookeeper there to create znode, delete znode, determine whether there is such as api, not one by one to try.

4、Apache Curator

The zookeeper connection java client there is something called curator.
Increased reliance

		<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 increase

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

connector arranged curator

@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 increase

#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

Test 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"));
    }
}