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zookeeper手把手教程（三）

zookeeper手把手教程（三）

作者: 黑白蓝调 | 来源:发表于2017-10-22 22:48 被阅读0次

    1. java API的使用

    1. 导入jar包
    <dependency>
    <groupId>org.apache.zookeeper</groupId>
    <artifactId>zookeeper</artifactId>
    <version>3.4.8</version>
</dependency>

    权限控制模式(ZooDefs.Ids.==ANYONE_ID_UNSAFE/AUTH_IDS/OPEN_ACL_UNSAFE/CREATOR_ALL_ACL/READ_ACL_UNSAFE==)

    • scheme 授权对象
    • ip :192.168.1.1
    • Digest :username:password
    • world :开放式的权限控制模式，数据节点的访问权限队所有用户开放。world:anyone
    • super :超级用户，可以对zookeeper上的数据节点进行操作
    package com.frame.test.gp.zookeeperAPI;

import org.apache.zookeeper.Watcher;

import com.frame.test.gp.zookeeperAPI.ZookeeperAPIDemo;
import org.apache.zookeeper.*;
import org.apache.zookeeper.data.ACL;
import org.apache.zookeeper.data.Id;
import org.apache.zookeeper.data.Stat;

import java.io.IOException;
import java.security.NoSuchAlgorithmException;
import java.util.ArrayList;
import java.util.List;
import java.util.concurrent.CountDownLatch;

public class AuthControlDemo implements Watcher {
    private final static String CONNECTSTRING="192.168.202.133:2181,192.168.202.134:2181,192.168.202.135:2181";
    private static CountDownLatch countDownLatch=new CountDownLatch(1);
    private static CountDownLatch countDownLatch2=new CountDownLatch(1);

    private static ZooKeeper zookeeper;
    private static Stat stat=new Stat();
    public static void main(String[] args) throws IOException, InterruptedException, KeeperException, NoSuchAlgorithmException {
        zookeeper=new ZooKeeper(CONNECTSTRING, 5000, new AuthControlDemo());
        countDownLatch.await();


        ACL acl=new ACL(ZooDefs.Perms.CREATE, new Id("digest","root:root"));
        ACL acl2=new ACL(ZooDefs.Perms.CREATE, new Id("ip","192.168.1.1"));

        List<ACL> acls=new ArrayList<>();
        acls.add(acl);
        //acls.add(acl2);
        zookeeper.create("/auth1","123".getBytes(),acls,CreateMode.PERSISTENT);
        zookeeper.addAuthInfo("digest","root:root".getBytes());

        zookeeper.create("/auth1","123".getBytes(), ZooDefs.Ids.CREATOR_ALL_ACL,CreateMode.PERSISTENT);

        zookeeper.create("/auth1/auth1-1","123".getBytes(),ZooDefs.Ids.CREATOR_ALL_ACL,CreateMode.PERSISTENT);

        ZooKeeper zooKeeper1= new ZooKeeper(CONNECTSTRING, 5000, new AuthControlDemo());
        countDownLatch.wait();;
        zooKeeper1.delete("/auth1",-1);

        // acl (create /delete /admin /read/write)
        //权限模式： ip/Digest（username:password）/world/super

    }
    public void process(WatchedEvent watchedEvent) {
        //如果当前的连接状态是连接成功的，那么通过计数器去控制
        if(watchedEvent.getState()==Event.KeeperState.SyncConnected){
            if(Event.EventType.None==watchedEvent.getType()&&null==watchedEvent.getPath()){
                countDownLatch.countDown();
                System.out.println(watchedEvent.getState()+"-->"+watchedEvent.getType());
            }
        }

    }
}
    1. 节点的增删改查，以及事件监听
    package com.frame.test.gp.zookeeperAPI;

import org.apache.zookeeper.*;
import org.apache.zookeeper.data.Stat;

import java.io.IOException;
import java.util.concurrent.CountDownLatch;
import java.util.concurrent.TimeUnit;

/**
 * @author Administrator
 * @CREATE 2017/8/5 21:21
 */
public class ZookeeperAPIDemo implements Watcher {
    private static final String CONNECTSTRING = "192.168.202.133:2181,192.168.202.134:2181,192.168.202.135:2181";

    private static ZooKeeper zookeeper;
    //concurrent 原子并发包的工具，需要查看
    private static CountDownLatch countDownLatch = new CountDownLatch(1);

    private static Stat stat = new Stat();

    public static ZooKeeper getConnection() throws IOException, InterruptedException {
        zookeeper = new ZooKeeper(ZookeeperAPIDemo.CONNECTSTRING, 5000, new ZookeeperAPIDemo());
        countDownLatch.await();
        return zookeeper;
    }

    /**
    *代码不复杂，每个都试验一下，配合到客户端操作验证结果
    */
    public static void main(String[] args) throws IOException, InterruptedException, KeeperException {
        zookeeper = getConnection();
        //创建节点
        String result =zookeeper.create("/node1","123".getBytes(), ZooDefs.Ids.OPEN_ACL_UNSAFE,CreateMode.EPHEMERAL);
        zookeeper.getData("/node1",new ZookeeperAPIDemo(),stat);
        System.out.println("创建成功:"+result);

        //修改节点
        zookeeper.setData("/node1","666".getBytes(),-1);
        System.out.println(zookeeper.getData("/node1",new ZookeeperAPIDemo(),stat));

        //删除节点，先从子节点删除，不然会报错，
        zookeeper.delete("/node1",-1);

        //创建持久化节点和子节点
        String path="/node11";
        zookeeper.create(path,"123".getBytes(),ZooDefs.Ids.OPEN_ACL_UNSAFE,CreateMode.PERSISTENT);
        TimeUnit.SECONDS.sleep(1);

        Stat stat=zookeeper.exists(path+"/node1",true);
        if (stat == null){
            zookeeper.create(path+"/node1","123".getBytes(),ZooDefs.Ids.OPEN_ACL_UNSAFE,CreateMode.PERSISTENT);
            TimeUnit.SECONDS.sleep(1);
        }

        //修改子路径
        zookeeper.setData(path+"/node1","mic123".getBytes(),-1);
        TimeUnit.SECONDS.sleep(1);

    }

    @Override
    public void process(WatchedEvent watchedEvent) {
        //如果当前的连接状态时成功的，那么通过计数器去控制
        if (watchedEvent.getState() == Event.KeeperState.SyncConnected) {
            if (Event.EventType.None == watchedEvent.getType() && null == watchedEvent.getPath()) {
                countDownLatch.countDown();
                System.out.println("process:"+watchedEvent.getState() + "-->" + watchedEvent.getType());
            } else if (watchedEvent.getType() == Event.EventType.NodeDataChanged) {
                try {
                    System.out.println("数据变更触发路径：" + watchedEvent.getPath() + "->改变后的值" + zookeeper.getData(watchedEvent.getPath(), true, stat));
                } catch (KeeperException e) {
                    e.printStackTrace();
                } catch (InterruptedException e) {
                    e.printStackTrace();
                }
            } else if (watchedEvent.getType() == Event.EventType.NodeChildrenChanged){  //子节点数据变化会触发
                try {
                    System.out.println("子节点数据变更路径："+watchedEvent.getPath()+"->节点的值："+ zookeeper.getData(watchedEvent.getPath(),true,stat));
                } catch (KeeperException e) {
                    e.printStackTrace();
                } catch (InterruptedException e) {
                    e.printStackTrace();
                }
            }else if (watchedEvent.getType()==Event.EventType.NodeCreated){   //创建子节点的时候回触发
                try {
                    System.out.println("节点创建路径："+watchedEvent.getPath()+"->节点的值："+ zookeeper.getData(watchedEvent.getPath(),true,stat));
                } catch (KeeperException e) {
                    e.printStackTrace();
                } catch (InterruptedException e) {
                    e.printStackTrace();
                }
            }else if (watchedEvent.getType()== Event.EventType.NodeDeleted){  //子节点删除会触发
                System.out.println("节点删除路径："+watchedEvent.getPath());
            }
            System.out.println("process:"+watchedEvent.getType());
        }
    }

}

    连接状态

    • KeeperStat.Expired 在一定时间内客户端没有收到服务器的通知，则认为当前的会话已经过期
    • KeeperStat.Disconnected 断开连接的状态
    • KeeperStat.SyncConnected 客户端和服务器端在某一个节点上建立连接，并且完成一次version、直到同步。
    • KeeperStat.authFailed 授权失败

    事件类型

    • NodeCreated 节点被创建的时候，触发
    • NodeChildrenChanged 表示子节点被创建、删除、子节点的数据发生变化
    • NodeDataChanged 节点数据发生变化
    • NodeDeleted 节点被删除
    • Node 客户端和服务器端连接状态发生变化的时候，事件类型就是None

    2. zkclient

    package com.frame.test.gp.zookeeperAPI;

import org.I0Itec.zkclient.IZkDataListener;
import org.I0Itec.zkclient.ZkClient;

import java.util.List;
import java.util.concurrent.TimeUnit;

/**
 * @author Administrator
 * @CREATE 2017/8/8 20:51
 */
public class zkClientApiOperatorDemo {
    private final static String CONNECTSTRING="192.168.202.133:2181,192.168.202.134:2181,192.168.202.135:2181";

    private static ZkClient getInstance(){

        return new ZkClient(CONNECTSTRING);
    }

    public static void main(String[] args) throws InterruptedException {
        ZkClient zkClient=getInstance();
        //zkclient 提供递归创建父节点功能
        zkClient.createPersistent("/zkclient/zkclient1",true);
        System.out.println("success");

        //删除节点
        //zkClient.delete("/auth1");
        //递归删除节点
        //zkClient.deleteRecursive("/zkclient");

        //获取父节点下的子节点
        List<String> list =zkClient.getChildren("/zkclient");
        System.out.println(list);

        //订阅数据修改事件
        zkClient.subscribeDataChanges("/zkclient", new IZkDataListener() {
            @Override
            public void handleDataChange(String dataPath, Object data) throws Exception {
                System.out.println(dataPath+"->"+data);
            }

            @Override
            public void handleDataDeleted(String dataPath) throws Exception {
                System.out.println("delete path"+dataPath);
            }
        });

        //修改节点数据
        zkClient.writeData("/zkclient","zkclient-data");
        TimeUnit.SECONDS.sleep(2);

        zkClient.deleteRecursive("/zkclient");
        TimeUnit.SECONDS.sleep(2);


    }
}

    3. curator

    • Curator是Netflix公司开源的zookeeper客户端;
    • curator-frameword 提供了fluent风格的api
    • curator-replice 提供了实现封装
    • curator链接的重试策略
    • ExponentialBackOffRetry() 衰减重试
    • RetryNtimes 指定最大重试次数
    • RetryOneTime 仅重试一次
    • RetryunitilElapsed 一直重试直到规定的时间
    <dependency>
    <groupId>org.apache.curator</groupId>
    <artifactId>curator-framework</artifactId>
    <version>2.9.0</version>
</dependency>
<dependency>
    <groupId>org.apache.curator</groupId>
    <artifactId>curator-client</artifactId>
    <version>2.9.0</version>
</dependency>
<dependency>
    <groupId>org.apache.curator</groupId>
    <artifactId>curator-recipes</artifactId>
    <version>2.9.0</version>
</dependency>

    ==pom同时存在zookeeper/zkclient/guava，就会报错，启动不了==

    package com.frame.test.gp.zookeeperAPI.curator;

import org.apache.curator.framework.CuratorFramework;
import org.apache.curator.framework.CuratorFrameworkFactory;
import org.apache.curator.retry.ExponentialBackoffRetry;

/**
 * @author Administrator
 * @CREATE 2017/8/8 22:17
 */
public class CuratorClientUtils {

    private static CuratorFramework curatorFramework;

    private final static String CONNECTSTRING = "192.168.202.133:2181,192.168.202.134:2181,192.168.202.135:2181";

    public static CuratorFramework getInstance() {
        //fluent 风格
         curatorFramework=CuratorFrameworkFactory.builder().connectString(CONNECTSTRING).sessionTimeoutMs(5000).retryPolicy(
                new ExponentialBackoffRetry(1000,3)).build();
        //normal
        //curatorFramework = CuratorFrameworkFactory.newClient(CONNECTSTRING, 5000, 5000, new ExponentialBackoffRetry(1000, 3));
        curatorFramework.start();
        return curatorFramework;
    }
}


    package com.frame.test.gp.zookeeperAPI.curator;

import org.apache.curator.framework.CuratorFramework;
import org.apache.curator.framework.CuratorFrameworkFactory;
import org.apache.curator.framework.api.BackgroundCallback;
import org.apache.curator.framework.api.CuratorEvent;
import org.apache.curator.framework.api.transaction.CuratorTransactionResult;
import org.apache.curator.retry.ExponentialBackoffRetry;
import org.apache.zookeeper.CreateMode;
import org.apache.zookeeper.data.Stat;

import java.util.Collection;
import java.util.Collections;
import java.util.concurrent.CountDownLatch;
import java.util.concurrent.ExecutorService;
import java.util.concurrent.Executors;

/**
 * @author Administrator
 * @CREATE 2017/8/8 21:25
 */
public class CuratorCreateSessionDemo {
    public static void main(String[] args) throws Exception {

        CuratorFramework curatorFramework = CuratorClientUtils.getInstance();
        System.out.println("连接成功.......");
        /**
         *【curator使用异常】KeeperErrorCode = Unimplemented for /***
         *Curator的版本过高造成，换成低一点版本即可 （version从3.0.0到2.9.1）
         */

        //新增节点，所有操作都可以在zkCli.sh 中验证。
        String result = curatorFramework.create().creatingParentsIfNeeded().withMode(CreateMode.PERSISTENT).forPath("/curator/curator1/curator11", "123".getBytes());
        System.out.println(result);

        //删除子节点
        curatorFramework.delete().forPath("/curator/curator1/curator11");

        //递归删除节点
        //curatorFramework.delete().deletingChildrenIfNeeded().forPath("/curator");

        //查询数据，以及状态
        Stat stat = new Stat();
        byte[] bytes = curatorFramework.getData().storingStatIn(stat).forPath("/curator");
        System.out.println(new String(bytes) + "-->state:" + stat);  //值 前面章节讲过；

        //更新
        Stat stat1 = curatorFramework.setData().forPath("/curator", "123".getBytes());
        System.out.println(stat1);


        /**
         * 特性:
         * 异步操作
         */
        ExecutorService executorService = Executors.newFixedThreadPool(1);
        CountDownLatch countDownLatch=new CountDownLatch(1);
        curatorFramework.create().creatingParentsIfNeeded().withMode(CreateMode.EPHEMERAL).inBackground(new BackgroundCallback() {
            @Override
            public void processResult(CuratorFramework client, CuratorEvent event) throws Exception {
                //创建节点是有线程池处理的，异步操作
                System.out.println(Thread.currentThread().getName() + "->resultCode:" + event.getResultCode() + "->" + event.getType());
                countDownLatch.countDown();
            }
        }, executorService).forPath("/sync", "123".getBytes());
        countDownLatch.await();
        executorService.shutdown();


        /**
         * 事务操作(curator独有的)
         */
        //在同一个事务，先创建一个transaction节点，然后又修改trans这个节点的值。 这样就会报错，修改的不是同一个节点。然后ls / ，发现zookeeper客户端并没有创建这个节点
        /*Collection<CuratorTransactionResult> resultCollection=curatorFramework.inTransaction().create().forPath("/transaction","transaction".getBytes()).and().setData().forPath("/trans","transaction roll back".getBytes()).and().commit();
        for (CuratorTransactionResult curatorTransactionResult:resultCollection){
            System.out.println(curatorTransactionResult.getForPath()+"->"+curatorTransactionResult.getType());
        }*/

        //在同一个事务，先创建一个transaction节点，然后又修改transaction这个节点的值。这样查看数据的值发现更新了
        Collection<CuratorTransactionResult> resultCollection1=curatorFramework.inTransaction().create().forPath("/transaction","transaction".getBytes()).and().setData().forPath("/transaction","transaction update ".getBytes()).and().commit();
        for (CuratorTransactionResult curatorTransactionResult:resultCollection1){
            System.out.println(curatorTransactionResult.getForPath()+"->"+curatorTransactionResult.getType());
        }
    }
}


    package com.frame.test.gp.zookeeperAPI.curator;

import org.apache.curator.framework.CuratorFramework;
import org.apache.curator.framework.recipes.cache.NodeCache;
import org.apache.curator.framework.recipes.cache.PathChildrenCache;
import org.apache.zookeeper.CreateMode;

import java.util.concurrent.TimeUnit;

/**
 * @author Administrator
 * @CREATE 2017/8/8 23:31
 */
public class CuratorEventDemo {
    /**
     * 三种watcher来做节点的监听
     * pathCache  监视一个路径下子节点的创建、删除、节点数据更新
     * NodeCache  监视一个节点的创建、更新、删除
     * TreeCache  pathCache + NOdeCache(监视路径下的创建、更新、删除事件)，缓存路径下所有子节点的数据
     */

    public static void main(String[] args) throws Exception {
        CuratorFramework curatorFramework = CuratorClientUtils.getInstance();

        /**
         * NodeCache
         */
        /*
        NodeCache cache=new NodeCache(curatorFramework,"/curator",false);
        cache.start();

        cache.getListenable().addListener(()-> System.out.println("节点数据发生变化，变化后的结果为："+new String(cache.getCurrentData().getData())));

        curatorFramework.setData().forPath("/curator","update".getBytes());*/


        /**
         * PathChildrenCache 监听/event 下的子节点
         */

        PathChildrenCache childrenCache = new PathChildrenCache(curatorFramework, "/event", true);
        //NORMAL: 初始时为空。
        //BUILD_INITIAL_CACHE: 在这个方法返回之前调用rebuild()。
        //POST_INITIALIZED_EVENT: 当Cache初始化数据后发送一个PathChildrenCacheEvent.Type #INITIALIZED事件
        childrenCache.start(PathChildrenCache.StartMode.NORMAL);
        childrenCache.getListenable().addListener((curatorFramework1, pathChildrenCacheEvent) -> {
            switch (pathChildrenCacheEvent.getType()) {
                case CHILD_ADDED:
                    System.out.println("增加子节点");
                    break;
                case CHILD_REMOVED:
                    System.out.println("删除子节点");
                    break;
                case CHILD_UPDATED:
                    System.out.println("更新子节点");
                    break;
                default:
                    break;
            }
        });

        curatorFramework.create().withMode(CreateMode.PERSISTENT).forPath("/event","events".getBytes());
        TimeUnit.SECONDS.sleep(1);
        System.out.println(1);

        //pathChildrenCache 会递归监听子节点时间,所以子节点创建打印出来了
        curatorFramework.create().withMode(CreateMode.EPHEMERAL).forPath("/event/event1","1".getBytes());
        TimeUnit.SECONDS.sleep(1);

        curatorFramework.setData().forPath("/event/event1","666".getBytes());
        TimeUnit.SECONDS.sleep(1);

        curatorFramework.delete().deletingChildrenIfNeeded().forPath("/event");
        System.in.read();
    }


}

    主要是动手，大家多动手多学习；--黑白 2017/8/9 0:21

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