ZkClient API使用

Maven工程方式导入ZkClient API

<dependency>
      <groupId>org.apache.zookeeper</groupId>
      <artifactId>zookeeper</artifactId>
      <version>3.4.10</version>
      <exclusions>
        <exclusion>
          <groupId>org.slf4j</groupId>
          <artifactId>slf4j-log4j12</artifactId>
        </exclusion>
        <exclusion>
          <groupId>log4j</groupId>
          <artifactId>log4j</artifactId>
        </exclusion>
      </exclusions>
    </dependency>

    <dependency>
      <groupId>com.101tec</groupId>
      <artifactId>zkclient</artifactId>
      <version>0.10</version>
    </dependency>

create session 创建和zookeeper集群间的连接

package com.timer.zkClientApi;

import org.I0Itec.zkclient.ZkClient;
import org.I0Itec.zkclient.serialize.SerializableSerializer;

/**
 * Created with IntelliJ IDEA.
 *
 * @author: zhubo
 * @description:
 *
    1）和zookeeper原生API不同，通过zkclient API创建会话，需要提供session timout, connection timeout两个定时器
    2）同时要提供1个序列化器实例，原因在于后续创建znode节点时，写入的数据（java对象）会自动通过序列化器来转换为byte[]
    3）同理，读取出的byte[]的数据，也会自动通过序列化器直接转换为Java对象

 * @time: 2018年06月04日
 * @modifytime:
 */
public class CreateSession {

    public static void main(String[] args) {
        ZkClient zkClient = new ZkClient("192.168.20.157:2181",5000,5000,new SerializableSerializer());

        System.out.println("Connection OK!");

    }
}

创建znode节点

package com.timer.zkClientApi;

import org.I0Itec.zkclient.ZkClient;
import org.I0Itec.zkclient.serialize.SerializableSerializer;
import org.apache.zookeeper.CreateMode;

/**
 * Created with IntelliJ IDEA.
 *
 * @author: zhubo
 * @description: 添加数据节点
 * @time: 2018年06月04日
 * @modifytime:
 */
public class CreateNode {

    public static void main(String[] args) {
        ZkClient zc = new ZkClient("192.168.20.157:2181", 5000, 5000, new SerializableSerializer());

        User u = new User();
        String actual_path = zc.create("/node_zkclient/ddd", u, CreateMode.PERSISTENT); //直接将实例u写入，自动通过序列化为byte[]
        System.out.println(actual_path);
    }
}

修改节点数据

package com.timer.zkClientApi;

import org.I0Itec.zkclient.ZkClient;
import org.I0Itec.zkclient.serialize.SerializableSerializer;
import org.apache.zookeeper.CreateMode;

/**
 * Created with IntelliJ IDEA.
 *
 * @author: zhubo
 * @description: 修改数据节点
 * @time: 2018年06月04日
 * @modifytime:
 */
public class NodeSetData {

    public static void main(String[] args) {
        ZkClient zc = new ZkClient("192.168.20.157:2181", 5000, 5000, new SerializableSerializer());
        User u = new User();
        u.setId(1L);
        u.setName("shayzhang");

        if(!zc.exists("/node_zkclient")){
            zc.create("/node_zkclient",u, CreateMode.PERSISTENT);
        }
        u.setId(2L);
        u.setName("zhangjin");

        zc.writeData("/node_zkclient",u);//直接写入实例，自动通过连接创建时创建的序列化实例，转换为byte[]
    }
}

获取节点数据

package com.timer.zkClientApi;

import org.I0Itec.zkclient.ZkClient;
import org.I0Itec.zkclient.serialize.SerializableSerializer;
import org.apache.zookeeper.CreateMode;
import org.apache.zookeeper.data.Stat;

/**
 * Created with IntelliJ IDEA.
 *
 * @author: zhubo
 * @description:
 * @time: 2018年06月04日
 * @modifytime:
 */
public class NodeGetData {

    public static void main(String[] args) {
        ZkClient zc = new ZkClient("192.168.20.157:2181", 5000, 5000, new SerializableSerializer());
        User u = new User();
        u.setId(1L);
        u.setName("shayzhang");
        String actual_path = zc.create("/node_zkclient", u, CreateMode.PERSISTENT);
        System.out.println("Create path is: " + actual_path);

        Stat stat = new Stat();
        zc.readData("/node_zkclient",stat);

        if(u == null){
            System.out.println("Node doesn't exist!");
        }else {
            System.out.println(u.getId());
            System.out.println(stat);
        }
    }
}

获取子节点列表

package com.timer.zkClientApi;

import org.I0Itec.zkclient.ZkClient;
import org.I0Itec.zkclient.serialize.SerializableSerializer;
import org.apache.zookeeper.CreateMode;

import java.util.List;

/**
 * Created with IntelliJ IDEA.
 *
 * @author: zhubo
 * @description: 获取子节点列表
 * @time: 2018年06月04日
 * @modifytime:
 */
public class NodeGetChildren {

    public static void main(String[] args) {
        ZkClient zc = new ZkClient("192.168.20.157:2181", 5000, 5000, new SerializableSerializer());
        if(!zc.exists("/node_zkclient")){
            User u = new User();
            u.setId(1L);
            u.setName("shayzhang");

            String actual_path = zc.create("/node_zkclient", u, CreateMode.PERSISTENT);
            System.out.println("Create path is: " + actual_path);
        }
        List<String> children_list  = zc.getChildren("/node_zkclient");
        System.out.println("Children list of /node_zkclient is : " + children_list.toString());  //打印子节点列表
    }

}

删除节点

package com.timer.zkClientApi;

import org.I0Itec.zkclient.ZkClient;
import org.I0Itec.zkclient.serialize.SerializableSerializer;

/**
 * Created with IntelliJ IDEA.
 *
 * @author: zhubo
 * @description: 删除节点
 * @time: 2018年06月04日
 * @modifytime:
 */
public class NodeDeleteNode {

    public static void main(String[] args) {
        ZkClient zc = new ZkClient("192.168.20.157:2181", 5000, 5000, new SerializableSerializer());
        String delete_node = "/node_zkclient/abc";

        if(zc.exists(delete_node)){
            //delete node without children
            boolean e1 = zc.delete(delete_node);
            System.out.println("Delete node without children: " + e1);
        }
        // delete node and all children
        boolean e2 = zc.deleteRecursive(delete_node);
        System.out.println("Delete node and children: " + e2);
    }
}

订阅子节点列表发生变化

package com.timer.zkClientApi;

import org.I0Itec.zkclient.IZkChildListener;
import org.I0Itec.zkclient.ZkClient;
import org.I0Itec.zkclient.serialize.SerializableSerializer;

import java.util.List;

/**
 * Created with IntelliJ IDEA.
 *
 * @author: zhubo
 * @description: 订阅子节点列表发生变化
 * @time: 2018年06月04日
 * @modifytime:
 */
public class SubscribeChildren {

    public static void main(String[] args) {
        ZkClient zc = new ZkClient("192.168.20.157:2181", 5000, 5000, new SerializableSerializer());
        System.out.println("Connected to zk server!");
        // subscribe children change event, multiple subscribe
        List<String> results = zc.subscribeChildChanges("/node_zkclient", new ZkChildListener());

        try{
            Thread.sleep(Long.MAX_VALUE);
        }catch (InterruptedException e){
            e.printStackTrace();
        }
    }
    private static class ZkChildListener implements IZkChildListener{
        @Override
        public void handleChildChange(String s, List<String> list) throws Exception {
            //print parent path
            System.out.println("Parent path: " + s);
            //print current children
            System.out.println("Current children: " + list.toString());
        }
    }
}

订阅数据变化

package com.timer.zkClientApi;

import org.I0Itec.zkclient.IZkDataListener;
import org.I0Itec.zkclient.ZkClient;
import org.I0Itec.zkclient.serialize.SerializableSerializer;

/**
 * Created with IntelliJ IDEA.
 *
 * @author: zhubo
 * @description: 订阅数据发生变化
 * @time: 2018年06月04日
 * @modifytime:
 */
public class SubscribeData {

    public static void main(String[] args) {
        ZkClient zc = new ZkClient("192.168.20.157:2181", 5000, 5000, new SerializableSerializer());
        System.out.println("Connected to zk server!");
        // subscribe data change event, multiple subscribe
        zc.subscribeDataChanges("/node_zkclient", new ZkDataListener());
        try{
            Thread.sleep(Long.MAX_VALUE);
        }catch (InterruptedException e){
            e.printStackTrace();
        }
    }

    private static class ZkDataListener implements IZkDataListener {
        @Override
        public void handleDataChange(String s, Object o) throws Exception {
            System.out.println("Path Data Changed: " + s);
            System.out.println("Current Data: " + o.toString());
        }
        @Override
        public void handleDataDeleted(String s) throws Exception {
            System.out.println("Data Deleted: " + s);
        }
    }
}