八：Zookeeper开源客户端Curator的api测试

curator是Netflix公司开源的一套ZooKeeper客户端，Curator解决了很多ZooKeeper客户端非常底层的细节开发工作。包括连接重连，反复注册Watcher等。实现了Fluent风格的API接口，目前已经为Apache的*项目，是全世界使用最广泛的ZooKeeper客户端之一

第一：maven依赖

 <dependency>
       <groupId>org.apache.curator</groupId>
       <artifactId>curator-framework</artifactId>
       <version>2.8.0</version>
     </dependency>
     <dependency>
       <groupId>org.apache.curator</groupId>
       <artifactId>curator-recipes</artifactId>
       <version>2.8.0</version>
     </dependency>

第二：测试的代码

 package com.yeepay.sxf.testrurator;

 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.CuratorFrameworkFactory.Builder;
 import org.apache.curator.framework.api.BackgroundCallback;
 import org.apache.curator.framework.api.CreateBuilder;
 import org.apache.curator.framework.api.CuratorEvent;
 import org.apache.curator.framework.api.CuratorEventType;
 import org.apache.curator.framework.api.DeleteBuilder;
 import org.apache.curator.framework.api.ExistsBuilder;
 import org.apache.curator.framework.api.GetChildrenBuilder;
 import org.apache.curator.framework.api.GetDataBuilder;
 import org.apache.curator.framework.api.SetDataBuilder;
 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.PathChildrenCacheEvent;
 import org.apache.curator.framework.recipes.cache.PathChildrenCacheEvent.Type;
 import org.apache.curator.framework.recipes.cache.PathChildrenCacheListener;
 import org.apache.curator.retry.ExponentialBackoffRetry;
 import org.apache.curator.retry.RetryNTimes;
 import org.apache.curator.retry.RetryUntilElapsed;
 import org.apache.zookeeper.CreateMode;
 import org.apache.zookeeper.data.Stat;

 /**
  * 测试Rurator客户端测试
  * @author sxf
  *
  */
 public class TestRurator {

     //创建一个线程池，让异步调用的的回调方法，申请线程池中的资源
     private static ExecutorService es=Executors.newFixedThreadPool(5);
     public static void main(String[] args) throws Exception {
                 //重试策略
                 RetryPolicy retryPolicy =new ExponentialBackoffRetry(1000, 3);

                 //客户端构建器
                 Builder builder=CuratorFrameworkFactory.builder();

                 builder.connectString("10.151.30.75:2181");//客户端链接地址：端口号
                 builder.sessionTimeoutMs(5000);//会话的超时时间
                 builder.connectionTimeoutMs(5000);//链接的超时时间
                 builder.retryPolicy(retryPolicy);//指定重试策略

                 //构建客户端
                 CuratorFramework client=builder.build();
                 client.start();

                 //测试创建节点
                 //testCreateNode(client);

                 //测试删除节点
                 //testDeleteNode(client);

                 //获取子节点列表
                 //getChildList(client);

                 //获取节点中存取的值
                 //getNodeValue(client);

                 //修改节点中存储数据的值
                 //updateNodeValue(client);

                 //判断一个节点是否存在
                 //isExistsNode(client);

                 //测试异步调用使用方法
                 //testSynCallBack(client);

                 //测试节点数据变动和节点被创建的事件足册
                 //nodeValueChangeListern(client);

                 //给某个节点注册监听其子节点的活动
                 nodeChildListernDothing(client);
                 Thread.sleep(Integer.MAX_VALUE);
     }

     /**
      * 建立客户端链接的第一种方法
      * @throws InterruptedException
      */
     public void testCreateSession() throws InterruptedException{
         //重试策略可以实现该接口。通过自定义规则，进行重试
         //重试链接的策略的接口
         //(最开始时间间隔，最多重试次数) 随着次数递增，时间间隔还会增加
         RetryPolicy retryPolicy =new ExponentialBackoffRetry(1000, 3);
         //(最多重试次数，每次重试间隔的时间长度)
         RetryPolicy retryPolicy2 =new RetryNTimes(5, 1000);
         //(重试时间的总长度，每次重试的时间间隔) 这个基本可重试10次
         RetryPolicy retryPolicy3 =new RetryUntilElapsed(10000, 1000);

         //(ip地址端口,会话超时时间，建立连接超时时间,重试链接的策略)
         CuratorFramework client=CuratorFrameworkFactory.newClient("10.151.30.75:2181", 5000,5000,retryPolicy);
         //启动链接
         client.start();

         Thread.sleep(Integer.MAX_VALUE);

     }

     /**
      * 建立客户端链接的第二种方法
      */
     public static void testCreateSession2(){
         //重试策略
         RetryPolicy retryPolicy =new ExponentialBackoffRetry(1000, 3);

         //客户端构建器
         Builder builder=CuratorFrameworkFactory.builder();

         builder.connectString("10.151.30.75:2181");//客户端链接地址：端口号
         builder.sessionTimeoutMs(5000);//会话的超时时间
         builder.connectionTimeoutMs(5000);//链接的超时时间
         builder.retryPolicy(retryPolicy);//指定重试策略
         builder.authorization(null);//给客户端添加权限AuthInfo 相关的知识在原生api里有讲过

 //        AuthInfo a=new AuthInfo("ip", "10.151.30.75:2181".getBytes());
 //        AuthInfo b=new AuthInfo("digest", "shangxiaofei:shangxiaofei".getBytes());

         //构建客户端
         CuratorFramework client=builder.build();

         //建立链接
         client.start();

     }

     /**
      * 测试创建节点(调用顺序)
      * 两种创建方式都可以
      * @throws Exception
      */
     public static void testCreateNode(CuratorFramework client) throws Exception{
         //创建节点构建器
 //        String path=client.create()
 //                                   .creatingParentsIfNeeded()//防止创建节点的父亲节点不存在，导致创建节点失败。如果父节点不存在，先创建父节点，再创建子节点
 //                                   .withMode(CreateMode.PERSISTENT)//指定节点的类型(持久节点，临时节点，持久节并顺序节点，临时并顺序节点)
 //                                   .forPath("/node_134", "xiaoshuai".getBytes());//节点路径，节点中存储的数据
 //
         CreateBuilder builder=client.create();
         builder.creatingParentsIfNeeded();
         builder.withMode(CreateMode.PERSISTENT);
         builder.withACL(null);//添加这个节点的权限。相关内容，在原生zookeeper客户端有讲解。上上篇博客
         /**
          * //基于ip的权限，意味着这个ip的客户端对此节点有读取权限
          *     ACL ipacl=new ACL(Perms.READ, new Id("ip", "10.151.30.75"));
          *     //基于digest的权限，意味着只有这个用户名和密码的客户端才能读取和写的权限
          *     ACL digetacl=new ACL(Perms.READ|Perms.WRITE,new Id("digest",DigestAuthenticationProvider.generateDigest("shangxiaofei:shangxiaofei")));
          *
          *     List<ACL> myaclAcls=new ArrayList<ACL>();
          *     myaclAcls.add(ipacl);
          *     myaclAcls.add(digetacl);
          */
         String pathString=builder.forPath("/node_135/node_135_2", "zhengjiuzhonghua".getBytes());

         System.out.println("TestRurator.testCreateNode()"+pathString);
     }

     /**
      * 测试删除节点(调用顺序不能乱)
      * @param client
      * @throws Exception
      */
     public static void testDeleteNode(CuratorFramework client) throws Exception{
         DeleteBuilder delteBuilder=client.delete();
         delteBuilder.guaranteed();//保证节点必须删除，如果删除出现错误，则后台程序会不断去尝试删除。
         delteBuilder.deletingChildrenIfNeeded();//如果存在子节点，先删除子节点
         delteBuilder.withVersion(-1);//指定版本号
         delteBuilder.forPath("/node_135");//指定路径
     }

     /**
      * 获取子节点列表
      * @param client
      * @throws Exception
      */
     public static void getChildList(CuratorFramework client) throws Exception{
         GetChildrenBuilder getChildBuilder=client.getChildren();
         List<String> nodelist=getChildBuilder.forPath("/");
         System.out.println("TestRurator.getChildList()"+nodelist);

     }
     /**
      * 获取节点中存取的值
      * @throws Exception
      */
     public static void getNodeValue(CuratorFramework client) throws Exception{

         GetDataBuilder dataBuilder=    client.getData();

         Stat stat=new Stat();
         dataBuilder.storingStatIn(stat);
         byte[] bytes=dataBuilder.forPath("/node_135/node_135_2");
         System.out.println("TestRurator.getNodeValue(data==>)"+new String(bytes));
         System.out.println("TestRurator.getNodeValue()"+stat);
     }

     /**
      * 修改节点中的数据
      * @param client
      * @throws Exception
      */
     public static void updateNodeValue(CuratorFramework client) throws Exception{
         SetDataBuilder setDataBuilder=client.setData();
         Stat stat=setDataBuilder.withVersion(-1).forPath("/node_135/node_135_2", "tianxiawushuang".getBytes());
         System.out.println("TestRurator.updateNodeValue()"+stat);
     }

     /**
      * 判断一个节点是否存在
      * @param client
      * @throws Exception
      */
     public static void isExistsNode(CuratorFramework client) throws Exception{
         ExistsBuilder existsBuilder=client.checkExists();
         Stat stat=existsBuilder.forPath("/node_135/node_135_2");
         if(stat!=null){
             System.out.println("TestRurator.isExistsNode()节点存在");
         }else{
             System.out.println("TestRurator.isExistsNode()节点不存在");
         }
     }
     /**
      * 以判断节点是否存在，讲解异步调用的使用
      * @param client
      * @throws Exception
      */
     public static void testSynCallBack(CuratorFramework client) throws Exception{
         ExistsBuilder existsBuilder=client.checkExists();
         existsBuilder.inBackground(new myBalckCallBack(),"sxf",es).forPath("/node_135/node_135_2");
         //System.out.println("TestRurator.testSynCallBack(异步调用返回)"+stat);
     }

     /**
      * 异步调用回调接口的实现类
      * @author sxf
      *
      */
     private static class myBalckCallBack implements BackgroundCallback{

         @Override
         public void processResult(CuratorFramework client, CuratorEvent event)
                 throws Exception {
                 //回调类型
                 CuratorEventType curatorEventType=event.getType();
                 //节点路径
                 String path=event.getPath();
                 //节点列表
                 List<String> list=event.getChildren();
                 //获取上下文
                 Object context=event.getContext();
                 //获取返回碼  异步操作成功，返回0
                 int code=event.getResultCode();
                 //获取数据内容
                 byte[] data=event.getData();

                 StringBuffer sb=new StringBuffer();
                 sb.append("curatorEventType="+curatorEventType).append("\n");
                 sb.append("path="+path).append("\n");
                 sb.append("list="+list).append("\n");
                 sb.append("context="+context).append("\n");
                 sb.append("data="+new String(data)).append("\n");

                 System.out.println(sb.toString());
         }

     }

     /**
      *节点事件监听(节点被创建，节点中存储的数据被修改)
      * @param client
      * @throws Exception
      */
     public  static void nodeValueChangeListern(CuratorFramework client) throws Exception{
         //注册监听
         final NodeCache nodeCache =new NodeCache(client, "/node_135/node_135_2");;
         //开启监听
         nodeCache.start();
         //添加监听器(实现指定接口的实例对象)
         nodeCache.getListenable().addListener(new NodeCacheListener() {

             @Override
             public void nodeChanged() throws Exception {
                 //获取当前节点的最近数据
                 byte[] bytes=nodeCache.getCurrentData().getData();
                 System.out.println(new String(bytes));

             }
         });
     }

     /**
      * 监听节点的子节点事件注册
      * @param client
      * @throws Exception
      */
     public static void nodeChildListernDothing(CuratorFramework client) throws Exception{
         //注册监听器
         //第三个参数：系统在监听到子节点列表发生变化时同时获取子节点的数据内容
         final PathChildrenCache cache=new PathChildrenCache(client, "/node_135", true);
         //开启监听
         cache.start();
         //注册监听器
         cache.getListenable().addListener(new PathChildrenCacheListener() {

             @Override
             public void childEvent(CuratorFramework client, PathChildrenCacheEvent event)
                     throws Exception {
                 Type type=event.getType();
                 switch (event.getType()) {
                 case CHILD_ADDED://添加子节点
                         System.out.println("新添加子节点中存储的值==>"+new String(event.getData().getData()));
                     break;

                 case CHILD_UPDATED://子节点被修改
                         System.out.println("被修改的子节点中存储的值==>"+new String(event.getData().getData()));
                     break;
                 case CHILD_REMOVED://子节点被删除
                         System.out.println("被删除的字节点的路径==>"+event.getInitialData());
                     break;

                 default:
                     break;
                 }

             }
         });
     }

 }