zookeeper的java客户端api学习笔记

zookeeper的java客户端api的使用样例。

package cn.itcast.bigdata.zk;import java.io.IOException;import java.util.List;import org.apache.zookeeper.CreateMode;import org.apache.zookeeper.KeeperException;import org.apache.zookeeper.WatchedEvent;import org.apache.zookeeper.Watcher;import org.apache.zookeeper.ZooDefs.Ids;import org.apache.zookeeper.ZooKeeper;import org.apache.zookeeper.data.Stat;import org.junit.Before;import org.junit.Test;public class SimpleZkClient {    private static final String connectString = "mini1:2181,mini2:2181,mini3:2181";    private static final int sessionTimeout = 2000;    ZooKeeper zkClient = null;    @Before    public void init() throws Exception {        zkClient = new ZooKeeper(connectString, sessionTimeout, new Watcher() {            @Override            public void process(WatchedEvent event) {                // 收到事件通知后的回调函数（应该是我们自己的事件处理逻辑）                System.out.println(event.getType() + "---" + event.getPath());                try {                    zkClient.getChildren("/", true);                } catch (Exception e) {                }            }        });    }    /**     * 数据的增删改查     *      * @throws InterruptedException     * @throws KeeperException     */    // 创建数据节点到zk中    public void testCreate() throws KeeperException, InterruptedException {        // 参数1：要创建的节点的路径 参数2：节点大数据 参数3：节点的权限 参数4：节点的类型        String nodeCreated = zkClient.create("/eclipse", "hellozk".getBytes(), Ids.OPEN_ACL_UNSAFE, CreateMode.PERSISTENT);        //上传的数据可以是任何类型，但都要转成byte[]    }    //判断znode是否存在    @Test       public void testExist() throws Exception{        Stat stat = zkClient.exists("/eclipse", false);        System.out.println(stat==null?"not exist":"exist");    }    // 获取子节点    @Test    public void getChildren() throws Exception {        List<String> children = zkClient.getChildren("/", true);        for (String child : children) {            System.out.println(child);        }        Thread.sleep(Long.MAX_VALUE);    }    //获取znode的数据    @Test    public void getData() throws Exception {        byte[] data = zkClient.getData("/eclipse", false, null);        System.out.println(new String(data));    }    //删除znode    @Test    public void deleteZnode() throws Exception {        //参数2：指定要删除的版本，-1表示删除所有版本        zkClient.delete("/eclipse", -1);    }    //删除znode    @Test    public void setData() throws Exception {        zkClient.setData("/app1", "imissyou angelababy".getBytes(), -1);        byte[] data = zkClient.getData("/app1", false, null);        System.out.println(new String(data));    }}