zookeeper手把手教程（三）

1. java API的使用

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

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

  • scheme 授權(quán)對象
  • ip :192.168.1.1
  • Digest :username:password
  • world :開放式的權(quán)限控制模式，數(shù)據(jù)節(jié)點的訪問權(quán)限隊所有用戶開放。world:anyone
  • super :超級用戶，可以對zookeeper上的數(shù)據(jù)節(jié)點進行操作
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)
        //權(quán)限模式： ip/Digest（username:password）/world/super

    }
    public void process(WatchedEvent watchedEvent) {
        //如果當前的連接狀態(tài)是連接成功的，那么通過計數(shù)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. 節(jié)點的增刪改查，以及事件監(jiān)聽
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 原子并發(fā)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;
    }

    /**
    *代碼不復雜，每個都試驗一下，配合到客戶端操作驗證結(jié)果
    */
    public static void main(String[] args) throws IOException, InterruptedException, KeeperException {
        zookeeper = getConnection();
        //創(chuàng)建節(jié)點
        String result =zookeeper.create("/node1","123".getBytes(), ZooDefs.Ids.OPEN_ACL_UNSAFE,CreateMode.EPHEMERAL);
        zookeeper.getData("/node1",new ZookeeperAPIDemo(),stat);
        System.out.println("創(chuàng)建成功:"+result);

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

        //刪除節(jié)點，先從子節(jié)點刪除，不然會報錯，
        zookeeper.delete("/node1",-1);

        //創(chuàng)建持久化節(jié)點和子節(jié)點
        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);
        }

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

    }

    @Override
    public void process(WatchedEvent watchedEvent) {
        //如果當前的連接狀態(tài)時成功的，那么通過計數(shù)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("數(shù)據(jù)變更觸發(fā)路徑：" + watchedEvent.getPath() + "->改變后的值" + zookeeper.getData(watchedEvent.getPath(), true, stat));
                } catch (KeeperException e) {
                    e.printStackTrace();
                } catch (InterruptedException e) {
                    e.printStackTrace();
                }
            } else if (watchedEvent.getType() == Event.EventType.NodeChildrenChanged){  //子節(jié)點數(shù)據(jù)變化會觸發(fā)
                try {
                    System.out.println("子節(jié)點數(shù)據(jù)變更路徑："+watchedEvent.getPath()+"->節(jié)點的值："+ zookeeper.getData(watchedEvent.getPath(),true,stat));
                } catch (KeeperException e) {
                    e.printStackTrace();
                } catch (InterruptedException e) {
                    e.printStackTrace();
                }
            }else if (watchedEvent.getType()==Event.EventType.NodeCreated){   //創(chuàng)建子節(jié)點的時候回觸發(fā)
                try {
                    System.out.println("節(jié)點創(chuàng)建路徑："+watchedEvent.getPath()+"->節(jié)點的值："+ zookeeper.getData(watchedEvent.getPath(),true,stat));
                } catch (KeeperException e) {
                    e.printStackTrace();
                } catch (InterruptedException e) {
                    e.printStackTrace();
                }
            }else if (watchedEvent.getType()== Event.EventType.NodeDeleted){  //子節(jié)點刪除會觸發(fā)
                System.out.println("節(jié)點刪除路徑："+watchedEvent.getPath());
            }
            System.out.println("process:"+watchedEvent.getType());
        }
    }

}

連接狀態(tài)

  • KeeperStat.Expired 在一定時間內(nèi)客戶端沒有收到服務(wù)器的通知，則認為當前的會話已經(jīng)過期
  • KeeperStat.Disconnected 斷開連接的狀態(tài)
  • KeeperStat.SyncConnected 客戶端和服務(wù)器端在某一個節(jié)點上建立連接，并且完成一次version、直到同步。
  • KeeperStat.authFailed 授權(quán)失敗

事件類型

  • NodeCreated 節(jié)點被創(chuàng)建的時候，觸發(fā)
  • NodeChildrenChanged 表示子節(jié)點被創(chuàng)建、刪除、子節(jié)點的數(shù)據(jù)發(fā)生變化
  • NodeDataChanged 節(jié)點數(shù)據(jù)發(fā)生變化
  • NodeDeleted 節(jié)點被刪除
  • Node 客戶端和服務(wù)器端連接狀態(tài)發(fā)生變化的時候，事件類型就是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 提供遞歸創(chuàng)建父節(jié)點功能
        zkClient.createPersistent("/zkclient/zkclient1",true);
        System.out.println("success");

        //刪除節(jié)點
        //zkClient.delete("/auth1");
        //遞歸刪除節(jié)點
        //zkClient.deleteRecursive("/zkclient");

        //獲取父節(jié)點下的子節(jié)點
        List<String> list =zkClient.getChildren("/zkclient");
        System.out.println(list);

        //訂閱數(shù)據(jù)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);
            }
        });

        //修改節(jié)點數(shù)據(jù)
        zkClient.writeData("/zkclient","zkclient-data");
        TimeUnit.SECONDS.sleep(2);

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


    }
}

3. curator

  • Curator是Netflix公司開源的zookeeper客戶端;
  • curator-frameword 提供了fluent風格的api
  • curator-replice 提供了實現(xiàn)封裝
  • curator鏈接的重試策略
  • ExponentialBackOffRetry() 衰減重試
  • RetryNtimes 指定最大重試次數(shù)
  • RetryOneTime 僅重試一次
  • RetryunitilElapsed 一直重試直到規(guī)定的時間
<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同時存在zookeeper/zkclient/guava，就會報錯，啟動不了==

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 風格
         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("連接成功.......");
        /**
         *【curator使用異?！縆eeperErrorCode = Unimplemented for /***
         *Curator的版本過高造成，換成低一點版本即可 （version從3.0.0到2.9.1）
         */

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

        //刪除子節(jié)點
        curatorFramework.delete().forPath("/curator/curator1/curator11");

        //遞歸刪除節(jié)點
        //curatorFramework.delete().deletingChildrenIfNeeded().forPath("/curator");

        //查詢數(shù)據(jù)，以及狀態(tài)
        Stat stat = new Stat();
        byte[] bytes = curatorFramework.getData().storingStatIn(stat).forPath("/curator");
        System.out.println(new String(bytes) + "-->state:" + stat);  //值 前面章節(jié)講過；

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


        /**
         * 特性:
         * 異步操作
         */
        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 {
                //創(chuàng)建節(jié)點是有線程池處理的，異步操作
                System.out.println(Thread.currentThread().getName() + "->resultCode:" + event.getResultCode() + "->" + event.getType());
                countDownLatch.countDown();
            }
        }, executorService).forPath("/sync", "123".getBytes());
        countDownLatch.await();
        executorService.shutdown();


        /**
         * 事務(wù)操作(curator獨有的)
         */
        //在同一個事務(wù)，先創(chuàng)建一個transaction節(jié)點，然后又修改trans這個節(jié)點的值。 這樣就會報錯，修改的不是同一個節(jié)點。然后ls / ，發(fā)現(xiàn)zookeeper客戶端并沒有創(chuàng)建這個節(jié)點
        /*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());
        }*/

        //在同一個事務(wù)，先創(chuàng)建一個transaction節(jié)點，然后又修改transaction這個節(jié)點的值。這樣查看數(shù)據(jù)的值發(fā)現(xiàn)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 {
    /**
     * 三種watcher來做節(jié)點的監(jiān)聽
     * pathCache  監(jiān)視一個路徑下子節(jié)點的創(chuàng)建、刪除、節(jié)點數(shù)據(jù)更新
     * NodeCache  監(jiān)視一個節(jié)點的創(chuàng)建、更新、刪除
     * TreeCache  pathCache + NOdeCache(監(jiān)視路徑下的創(chuàng)建、更新、刪除事件)，緩存路徑下所有子節(jié)點的數(shù)據(jù)
     */

    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("節(jié)點數(shù)據(jù)發(fā)生變化，變化后的結(jié)果為："+new String(cache.getCurrentData().getData())));

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


        /**
         * PathChildrenCache 監(jiān)聽/event 下的子節(jié)點
         */

        PathChildrenCache childrenCache = new PathChildrenCache(curatorFramework, "/event", true);
        //NORMAL: 初始時為空。
        //BUILD_INITIAL_CACHE: 在這個方法返回之前調(diào)用rebuild()。
        //POST_INITIALIZED_EVENT: 當Cache初始化數(shù)據(jù)后發(fā)送一個PathChildrenCacheEvent.Type #INITIALIZED事件
        childrenCache.start(PathChildrenCache.StartMode.NORMAL);
        childrenCache.getListenable().addListener((curatorFramework1, pathChildrenCacheEvent) -> {
            switch (pathChildrenCacheEvent.getType()) {
                case CHILD_ADDED:
                    System.out.println("增加子節(jié)點");
                    break;
                case CHILD_REMOVED:
                    System.out.println("刪除子節(jié)點");
                    break;
                case CHILD_UPDATED:
                    System.out.println("更新子節(jié)點");
                    break;
                default:
                    break;
            }
        });

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

        //pathChildrenCache 會遞歸監(jiān)聽子節(jié)點時間,所以子節(jié)點創(chuàng)建打印出來了
        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();
    }


}

主要是動手，大家多動手多學習；--黑白 2017/8/9 0:21

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