zookeeper客户端curator简易使用
写在前面：目前Curator有2.x.x和3.x.x两个系列的版本，支持不同版本的Zookeeper。其中Curator 2.x.x兼容Zookeeper的3.4.x和3.5.x。而Curator 3.x.x只兼容Zookeeper 3.5.x，并且提供了一些诸如动态重新配置、watch删除等新特性。本文是基于docker容器创建zookeeper环境，读者请自行选择zookeeper环境。如若读者想在centos安装docker，请参考《centos中简易安装docker》https://blog.csdn.net/belonghuang157405/article/details/80774506
本文参考文章：https://blog.csdn.net/haoyuyang/article/details/53469269
完整代码地址：https://github.com/Blankwhiter/curator
第一步 搭建zookeeper环境
在centos中，拉取zookeeper镜像，以及创建zookeeper容器。
docker pull zookeeper
docker run -d -v /home/soft/zookeeperhost/zookeeperDataDir:/data -v /home/soft/zookeeperhost/zookeeperDataLogDir:/datalog -e ZOO_MY_ID=1 -e ZOO_SERVERS='server.1=192.168.9.129:2888:3888'--net=host --privileged zookeeper注：192.168.9.129读者请自行改为本机ip，此文采用的单例，而非集群，如需集群 读者请自行创建.192.168.9.129
第二步 curator依赖加入
在pox.xml中加入curator包：
<dependency>
<groupId>org.apache.curator</groupId>
<artifactId>curator-recipes</artifactId>
<version>2.12.0</version>
</dependency>
第三步 测试crud操作
import org.apache.curator.framework.CuratorFramework;
import org.apache.curator.framework.CuratorFrameworkFactory;
import org.apache.curator.framework.recipes.cache.*;
import org.apache.curator.retry.ExponentialBackoffRetry;
import org.apache.zookeeper.data.Stat;
/**
* curator测试crud操作
*/
public class CuratorClientTest {
/**
* Zookeeper info 集群用,隔开，如192.168.9.127:2181,192.168.9.128:2181,192.168.9.129:2181
*/
private static final String ZK_ADDRESS = "192.168.9.129:2181";
/**
* 创建路径
*/
private static final String ZK_PATH_PARENT = "/new1";
private static final String ZK_PATH = "/new1/mytest";
public static void main(String[] args) throws Exception {
CuratorFramework client = getClient();
/*
开始连接
*/
client.start();
// initNodeCache(client);
// initPathChildrenCache(client);
initTreeCache(client);
createNode(client);
/*
普通查询
*/
byte[] bytes = client.getData().forPath(ZK_PATH);
System.out.println(new String(bytes));
/*
包含状态查询
*/
Stat stat = new Stat();
byte[] bytes1 = client.getData().storingStatIn(stat).forPath(ZK_PATH);
System.out.println(new String(bytes1));
// updateNode(client);
// deleteNode(client);
Thread.sleep(15000);
/*
关闭连接
*/
client.close();
}
/**
* 删除节点
*
* @param client
* @throws Exception
*/
public static void deleteNode(CuratorFramework client) throws Exception {
/*
删除节点
*/
// client.delete().forPath(ZK_PATH);
/*
删除节点 并且递归删除子节点
*/
// client.delete().deletingChildrenIfNeeded().forPath(ZK_PATH);
client.delete().guaranteed().forPath(ZK_PATH);
}
/**
* 更新节点内容
*/
public static void updateNode(CuratorFramework client) throws Exception {
/*
更新节点信息 如果未传入version参数，那么更新当前最新版本
*/
client.setData().forPath(ZK_PATH, "新内容3".getBytes());
/*
指定版本更新 版本不一直异常信息：org.apache.zookeeper.KeeperException$BadVersionException: KeeperErrorCode = BadVersion for
*/
// client.setData().withVersion(aversion).forPath(ZK_PATH);
}
/**
* 创建节点信息以及内容
*
* @param client
* @throws Exception
*/
public static void createNode(CuratorFramework client) throws Exception {
/*
创建节点以及对应内容。无法递归创建节点
*/
client.create().forPath(ZK_PATH + "/noCursion", "noCursion".getBytes());
// client.create().forPath(ZK_PATH_PARENT,"noCursion".getBytes());
/*
递归创建节点以及对应内容
*/
client.create().creatingParentsIfNeeded().forPath(ZK_PATH, "testdata".getBytes());
// client.create().forPath(ZK_PATH_PARENT).
}
/**
* 获得客户端连接
*
* @return
*/
public static CuratorFramework getClient() {
/*
重试策略
*/
ExponentialBackoffRetry exponentialBackoffRetry = new ExponentialBackoffRetry(1000, 3);
/*
CuratorFrameworkFactory工厂创建实例
*/
return CuratorFrameworkFactory.newClient(ZK_ADDRESS, exponentialBackoffRetry);
}
/**
* 初始化TreeCache的节点监听
*
* @param client
* @throws Exception
*/
public static void initTreeCache(CuratorFramework client) throws Exception {
TreeCache treeCache = new TreeCache(client, ZK_PATH_PARENT);
treeCache.start();
treeCache.getListenable().addListener((curatorFramework, treeCacheEvent) -> {
switch (treeCacheEvent.getType()) {
case NODE_ADDED:
System.out.println("NODE_ADDED：路径：" + treeCacheEvent.getData().getPath() + "，数据：" + new String(treeCacheEvent.getData().getData())
+ "，状态：" + treeCacheEvent.getData().getStat());
break;
case NODE_UPDATED:
System.out.println("NODE_UPDATED：路径：" + treeCacheEvent.getData().getPath() + "，数据：" + new String(treeCacheEvent.getData().getData())
+ "，状态：" + treeCacheEvent.getData().getStat());
break;
case NODE_REMOVED:
System.out.println("NODE_REMOVED：路径：" + treeCacheEvent.getData().getPath() + "，数据：" + new String(treeCacheEvent.getData().getData())
+ "，状态：" + treeCacheEvent.getData().getStat());
break;
default:
break;
}
});
}
/**
* 初始化节点监听
*
* @param client
* @throws Exception
*/
public static void initNodeCache(CuratorFramework client) throws Exception {
/*
监听节点的新增、修改操作。 最后一个参数表示是否进行压缩
*/
NodeCache nodeCache = new NodeCache(client, ZK_PATH_PARENT, false);
nodeCache.start(true);
/*
会监听父节点的创建和修改，删除不会监听
*/
nodeCache.getListenable().addListener(() -> {
System.out.println("nodeCache listen begin");
System.out.println("data:" + nodeCache.getCurrentData().getData().toString());
System.out.println("nodeCache listen end");
});
}
/**
* 初始化子节点监听
*
* @param client
* @throws Exception
*/
public static void initPathChildrenCache(CuratorFramework client) throws Exception {
/*
监听子节点的新增、修改、删除操作。
*/
PathChildrenCache pathChildrenCache = new PathChildrenCache(client, ZK_PATH_PARENT, true);
/**
* 如果不填写这个参数，则无法监听到子节点的数据更新
如果参数为PathChildrenCache.StartMode.BUILD_INITIAL_CACHE，则会预先创建之前指定的/super节点
如果参数为PathChildrenCache.StartMode.POST_INITIALIZED_EVENT，效果与BUILD_INITIAL_CACHE相同，只是不会预先创建/super节点
参数为PathChildrenCache.StartMode.NORMAL时，与不填写参数是同样的效果，不会监听子节点的数据更新操作
*/
pathChildrenCache.start(PathChildrenCache.StartMode.POST_INITIALIZED_EVENT);
pathChildrenCache.getListenable().addListener((curatorFramework, event) -> {
switch (event.getType()) {
case CHILD_ADDED:
System.out.println("CHILD_ADDED，类型：" + event.getType() + "，路径：" + event.getData().getPath() + "，数据：" +
new String(event.getData().getData()) + "，状态：" + event.getData().getStat());
break;
case CHILD_UPDATED:
System.out.println("CHILD_UPDATED，类型：" + event.getType() + "，路径：" + event.getData().getPath() + "，数据：" +
new String(event.getData().getData()) + "，状态：" + event.getData().getStat());
break;
case CHILD_REMOVED:
System.out.println("CHILD_REMOVED，类型：" + event.getType() + "，路径：" + event.getData().getPath() + "，数据：" +
new String(event.getData().getData()) + "，状态：" + event.getData().getStat());
break;
default:
break;
}
});
}