zookeeper入门之Curator的使用之几种监听器的使用
package com.git.zookeeper.passwordmanager.listener;import java.util.ArrayList;import java.util.List;import java.util.concurrent.ExecutorService;import java.util.concurrent.Executors;import org.
·
package com.git.zookeeper.passwordmanager.listener;
import java.util.ArrayList;
import java.util.List;
import java.util.concurrent.ExecutorService;
import java.util.concurrent.Executors;
import org.apache.curator.RetryPolicy;
import org.apache.curator.framework.CuratorFramework;
import org.apache.curator.framework.CuratorFrameworkFactory;
import org.apache.curator.framework.api.ACLProvider;
import org.apache.curator.framework.api.CuratorEvent;
import org.apache.curator.framework.api.CuratorListener;
import org.apache.curator.framework.recipes.cache.ChildData;
import org.apache.curator.framework.recipes.cache.NodeCache;
import org.apache.curator.framework.recipes.cache.NodeCacheListener;
import org.apache.curator.framework.recipes.cache.PathChildrenCache;
import org.apache.curator.framework.recipes.cache.PathChildrenCache.StartMode;
import org.apache.curator.framework.recipes.cache.PathChildrenCacheEvent;
import org.apache.curator.framework.recipes.cache.PathChildrenCacheListener;
import org.apache.curator.framework.recipes.cache.TreeCache;
import org.apache.curator.framework.recipes.cache.TreeCacheEvent;
import org.apache.curator.framework.recipes.cache.TreeCacheListener;
import org.apache.curator.retry.ExponentialBackoffRetry;
import org.apache.curator.retry.RetryNTimes;
import org.apache.zookeeper.WatchedEvent;
import org.apache.zookeeper.Watcher;
import org.apache.zookeeper.ZooDefs;
import org.apache.zookeeper.ZooDefs.Perms;
import org.apache.zookeeper.data.ACL;
import org.apache.zookeeper.data.Id;
/**
* curator管理zookeeper的相关方法工具类
* @author songqinghu
* 要点:
* 1.连接的建立 (两种 OK--使用权限方式)
* 2.节点的管理操作,增删改查--层叠节点的操作(OK --设立命名空间)
* 3.节点的监听操作,和无限监听事件触发(OK --使用第三种方法)
* 4.节点的访问控制ACL操作,密码的添加,修改-->连接中设置
* 5.节点原子性操作
* 6.节点的分布式锁操作
* 7.分布式队列
*/
public class CuratorListenerUtils {
/**
* 先测试玩玩
* @描述:XXXXXXX
* @param args
* @return void
* @exception
* @createTime:2016年5月17日
* @author: songqinghu
* @throws Exception
*/
public static void main(String[] args) throws Exception {
CuratorFramework client = clientTwo();
//setListenterDateNode();
//setListenterThreeOne(client);
// setListenterThreeTwo(client);
setListenterThreeThree(client);
// getDataNode(client, "/two");
// setDataNode(client, "/two", "sss");
Thread.sleep(Long.MAX_VALUE);
}
/**
*
* @描述:创建一个zookeeper连接---连接方式一: 最简单的连接
* @return void
* @exception
* @createTime:2016年5月17日
* @author: songqinghu
*/
private static CuratorFramework clientOne(){
//zk 地址
String connectString = "10.125.2.44:2181";
// 连接时间 和重试次数
RetryPolicy retryPolicy = new ExponentialBackoffRetry(1000, 3);
CuratorFramework client = CuratorFrameworkFactory.newClient(connectString, retryPolicy);
client.start();
return client;
}
/**
*
* @描述:创建一个zookeeper连接---连接方式二:优选这个
* @return void
* @exception
* @createTime:2016年5月17日
* @author: songqinghu
*/
private static CuratorFramework clientTwo(){
//默认创建的根节点是没有做权限控制的--需要自己手动加权限???----
ACLProvider aclProvider = new ACLProvider() {
private List<ACL> acl ;
@Override
public List<ACL> getDefaultAcl() {
if(acl ==null){
ArrayList<ACL> acl = ZooDefs.Ids.CREATOR_ALL_ACL;
acl.clear();
acl.add(new ACL(Perms.ALL, new Id("auth", "admin:admin") ));
this.acl = acl;
}
return acl;
}
@Override
public List<ACL> getAclForPath(String path) {
return acl;
}
};
String scheme = "digest";
byte[] auth = "admin:admin".getBytes();
int connectionTimeoutMs = 5000;
String connectString = "10.125.2.44:2181";
String namespace = "testnamespace";
CuratorFramework client = CuratorFrameworkFactory.builder().aclProvider(aclProvider).
authorization(scheme, auth).
connectionTimeoutMs(connectionTimeoutMs).
connectString(connectString).
namespace(namespace).
retryPolicy(new RetryNTimes(Integer.MAX_VALUE, 1000)).build();
client.start();
return client;
}
/**
*
* @描述:第一种监听器的添加方式: 对指定的节点进行添加操作
* 仅仅能监控指定的本节点的数据修改,删除 操作 并且只能监听一次 --->不好
* @return void
* @exception
* @createTime:2016年5月18日
* @author: songqinghu
* @throws Exception
*/
private static void setListenterOne(CuratorFramework client) throws Exception{
// 注册观察者,当节点变动时触发
byte[] data = client.getData().usingWatcher(new Watcher() {
@Override
public void process(WatchedEvent event) {
System.out.println("获取 two 节点 监听器 : " + event);
}
}).forPath("/two");
System.out.println("two 节点数据: "+ new String(data));
}
/**
*
* @描述:第二种监听器的添加方式:
* 也是一次性的监听操作,使用后就无法在继续监听了
* @return void
* @exception
* @createTime:2016年5月18日
* @author: songqinghu
* @throws Exception
*/
private static void setListenterTwo(CuratorFramework client) throws Exception{
ExecutorService pool = Executors.newCachedThreadPool();
CuratorListener listener = new CuratorListener() {
@Override
public void eventReceived(CuratorFramework client, CuratorEvent event) throws Exception {
System.out.println("监听器 : "+ event.toString());
}
};
client.getCuratorListenable().addListener(listener,pool);
client.getData().inBackground().forPath("/two");
client.getData().inBackground().forPath("/two");
client.getData().inBackground().forPath("/two");
client.getData().inBackground().forPath("/two");
Thread.sleep(Long.MAX_VALUE );
}
/**
*
* @描述:第三种监听器的添加方式: Cache 的三种实现 实践
* Path Cache:监视一个路径下1)孩子结点的创建、2)删除,3)以及结点数据的更新。
* 产生的事件会传递给注册的PathChildrenCacheListener。
* Node Cache:监视一个结点的创建、更新、删除,并将结点的数据缓存在本地。
* Tree Cache:Path Cache和Node Cache的“合体”,监视路径下的创建、更新、删除事件,并缓存路径下所有孩子结点的数据。
* @return void
* @exception
* @createTime:2016年5月18日
* @author: songqinghu
* @throws Exception
*/
//1.path Cache 连接 路径 是否获取数据
//能监听所有的字节点 且是无限监听的模式 但是 指定目录下节点的子节点不再监听
private static void setListenterThreeOne(CuratorFramework client) throws Exception{
ExecutorService pool = Executors.newCachedThreadPool();
PathChildrenCache childrenCache = new PathChildrenCache(client, "/test", true);
PathChildrenCacheListener childrenCacheListener = new PathChildrenCacheListener() {
@Override
public void childEvent(CuratorFramework client, PathChildrenCacheEvent event) throws Exception {
System.out.println("开始进行事件分析:-----");
ChildData data = event.getData();
switch (event.getType()) {
case CHILD_ADDED:
System.out.println("CHILD_ADDED : "+ data.getPath() +" 数据:"+ data.getData());
break;
case CHILD_REMOVED:
System.out.println("CHILD_REMOVED : "+ data.getPath() +" 数据:"+ data.getData());
break;
case CHILD_UPDATED:
System.out.println("CHILD_UPDATED : "+ data.getPath() +" 数据:"+ data.getData());
break;
default:
break;
}
}
};
childrenCache.getListenable().addListener(childrenCacheListener);
System.out.println("Register zk watcher successfully!");
childrenCache.start(StartMode.POST_INITIALIZED_EVENT);
}
//2.Node Cache 监控本节点的变化情况 连接 目录 是否压缩
//监听本节点的变化 节点可以进行修改操作 删除节点后会再次创建(空节点)
private static void setListenterThreeTwo(CuratorFramework client) throws Exception{
ExecutorService pool = Executors.newCachedThreadPool();
//设置节点的cache
final NodeCache nodeCache = new NodeCache(client, "/test", false);
nodeCache.getListenable().addListener(new NodeCacheListener() {
@Override
public void nodeChanged() throws Exception {
System.out.println("the test node is change and result is :");
System.out.println("path : "+nodeCache.getCurrentData().getPath());
System.out.println("data : "+new String(nodeCache.getCurrentData().getData()));
System.out.println("stat : "+nodeCache.getCurrentData().getStat());
}
});
nodeCache.start();
}
//3.Tree Cache
// 监控 指定节点和节点下的所有的节点的变化--无限监听 可以进行本节点的删除(不在创建)
private static void setListenterThreeThree(CuratorFramework client) throws Exception{
ExecutorService pool = Executors.newCachedThreadPool();
//设置节点的cache
TreeCache treeCache = new TreeCache(client, "/test");
//设置监听器和处理过程
treeCache.getListenable().addListener(new TreeCacheListener() {
@Override
public void childEvent(CuratorFramework client, TreeCacheEvent event) throws Exception {
ChildData data = event.getData();
if(data !=null){
switch (event.getType()) {
case NODE_ADDED:
System.out.println("NODE_ADDED : "+ data.getPath() +" 数据:"+ new String(data.getData()));
break;
case NODE_REMOVED:
System.out.println("NODE_REMOVED : "+ data.getPath() +" 数据:"+ new String(data.getData()));
break;
case NODE_UPDATED:
System.out.println("NODE_UPDATED : "+ data.getPath() +" 数据:"+ new String(data.getData()));
break;
default:
break;
}
}else{
System.out.println( "data is null : "+ event.getType());
}
}
});
//开始监听
treeCache.start();
}
}
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