ZooKeeper学习笔记-6---ZkClient使用

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ZkClient是一个开源的ZooKeeper客户端，是在原生的ZooKeeper API接口之上进行包装，是一个更易使用的ZooKeeper客户端。ZkClient在内部实现了Session超时重连、Watcher反复注册等功能，使得ZooKeeper客户端的繁琐细节对开发人员透明。
接下来，我们将从创建会话、创建节点、读取数据、更新数据、删除节点、检测节点等方面介绍ZkClient的使用。

1.会话创建、节点创建、获取子节点、删除节点

public class ZkClientTest {    public static void main(String[] args) throws IOException,InterruptedException {        //创建会话        ZkClient zkClient = new ZkClient("127.0.0.1:2181", 5000);        String path = "/zk-book";        //监测子节点变化        zkClient.subscribeChildChanges(path, new IZkChildListener() {               @Override            public void handleChildChange(String parentPath, List<String> currentChild)                    throws Exception {                System.out.println(parentPath + " 's child changed ,currentChilds: " + currentChild);            }        });        //创建节点        zkClient.createPersistent(path);        Thread.sleep(1000);        System.out.println(zkClient.getChildren(path));        Thread.sleep(1000);        zkClient.createPersistent(path + "/c1");        Thread.sleep(1000);        System.out.println(zkClient.getChildren(path));        Thread.sleep(1000);        zkClient.createPersistent(path + "/c2","123");        Thread.sleep(1000);        System.out.println(zkClient.getChildren(path));        //删除节点        Thread.sleep(1000);        zkClient.delete(path + "/c1");        Thread.sleep(1000);        System.out.println(zkClient.getChildren(path));        zkClient.delete(path + "/c2");        System.out.println(zkClient.getChildren(path));         Thread.sleep(1000);         }}

输出结果：

/zk-book 's child changed ,currentChilds: [][]/zk-book 's child changed ,currentChilds: [c1][c1]/zk-book 's child changed ,currentChilds: [c1, c2][c1, c2]/zk-book 's child changed ,currentChilds: [c2][c2][]/zk-book 's child changed ,currentChilds: []

2.改变节点数据、检测节点是否存在

public class ZkClientTest {    public static void main(String[] args) throws InterruptedException   {        //创建会话        ZkClient zkClient = new ZkClient("127.0.0.1:2181", 5000);        //创建节点        String path = "/zk-book";        zkClient.createPersistent(path,"123");        //监测节点数据变化        zkClient.subscribeDataChanges(path, new IZkDataListener() {            @Override            public void handleDataDeleted(String dataPath) throws Exception {                System.out.println("Node " + dataPath + " deleted.");            }            @Override            public void handleDataChange(String dataPath, Object data) throws Exception {                System.out.println("Node " + dataPath + " changed, new data: " +data);            }        });        //读取节点数据        System.out.println(zkClient.readData(path));        zkClient.writeData(path, "456");        Thread.sleep(1000);        System.out.println("Node exists :" + zkClient.exists(path));        zkClient.delete(path);        System.out.println("Node exists :" + zkClient.exists(path));    }}

输出结果：

123Node /zk-book changed, new data: 456Node exists :trueNode exists :false

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