ZooKeeper原生java客户端使用

准备：

要么使用maven，要么手动引入zookeeper-3.4.6.jar和zk包lib文件夹下的jar包，slf4j-api-1.6.1.jar等

示例代码：

同步接口：

package raw_client;

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

import org.apache.zookeeper.CreateMode;
import org.apache.zookeeper.KeeperException;
import org.apache.zookeeper.WatchedEvent;
import org.apache.zookeeper.Watcher;
import org.apache.zookeeper.Watcher.Event.EventType;
import org.apache.zookeeper.Watcher.Event.KeeperState;
import org.apache.zookeeper.ZooDefs.Ids;
import org.apache.zookeeper.ZooKeeper;
import org.apache.zookeeper.data.Stat;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

public class SyncApi implements Watcher
{
    private static CountDownLatch connectedSemaphore = new CountDownLatch(1);
    
    private static Stat stat = new Stat();
    
    private static final Logger log = LoggerFactory.getLogger(SyncApi.class);
    
    static ZooKeeper zk = null;
    
    static String path = "/zk_test";
    
    public static void main(String[] args) throws IOException, InterruptedException, KeeperException
    {
        // ----------------------连接---------------------------
        // 直接连连不上 state: Expired
        long sessionID = 1111111;
        String sessionPWD = "s1_pwd";
        SyncApi sa = new SyncApi();
        zk = new ZooKeeper("127.0.0.1:2181", 5000, sa, sessionID, sessionPWD.getBytes());
        log.info("ZooKeeper state: " + zk.getState());
        
        ZooKeeper zk1 = new ZooKeeper("127.0.0.1:2181", 5000, sa);
        
        long sessionId = zk1.getSessionId();
        byte[] passwd = zk1.getSessionPasswd();
        connectedSemaphore.await();
        log.info("ZooKeeper session established.");
        // 错误的session state: Expired
        zk = new ZooKeeper("127.0.0.1:2181", 5000, sa, 1l, "test".getBytes());
        // 正确的session state: SyncConnected
        zk = new ZooKeeper("127.0.0.1:2181", 5000, sa, sessionId, passwd);
        zk.exists(path, true);
        //----------------------------创建节点------------------------
        String pPath = zk.create(path, "fad".getBytes(), Ids.OPEN_ACL_UNSAFE, CreateMode.PERSISTENT);
        // 下面这行报NodeExistsException
        //        zk.create(path, "fad".getBytes(), Ids.OPEN_ACL_UNSAFE, CreateMode.EPHEMERAL);
        String esPath = zk.create(path, "fad".getBytes(), Ids.OPEN_ACL_UNSAFE, CreateMode.EPHEMERAL_SEQUENTIAL);
        String psPath = zk.create(path, "fad".getBytes(), Ids.OPEN_ACL_UNSAFE, CreateMode.PERSISTENT_SEQUENTIAL);
        /* java进程结束后，临时节点消失
        [zk: localhost:2181(CONNECTED) 29] ls /
        [zk_test0000000011, zookeeper, zk_test0000000010, zk_test]
        [zk: localhost:2181(CONNECTED) 30] ls /
        [zk_test0000000011, zookeeper, zk_test]*/
        
        //----------------------------删除节点------------------------
        zk.delete(psPath, -1);
        zk.delete(esPath, 0);
        // 下面这行报BadVersion
        //        zk.delete(pPath, 10);
        
        //----------------------------获取数据------------------------
        log.info(new String(zk.getData(path, sa, stat)));
        log.info("Signature: " + stat.signature() + " Ctime: " + stat.getCtime() + " Aversion: " + stat.getAversion()
                + " Cversion: " + stat.getCversion() + " Czxid: " + stat.getCzxid() + " DataLength: "
                + stat.getDataLength() + " Mtime: " + stat.getMtime() + " Mzxid: " + stat.getMzxid() + " NumChildren: "
                + stat.getNumChildren() + " Version: " + stat.getVersion() + " Pzxid: " + stat.getPzxid());
        //----------------------------更新数据------------------------
        // 测试watcher,下面这行触发NodeDataChanged类型的事件
        zk.setData(path, "update123".getBytes(), 0);
        
        //----------------------------获取子节点------------------------
        List<String> childrenList = zk.getChildren(path, sa, stat);
        log.info(childrenList.toString());
        zk.create(path + "/c1", "c11111111".getBytes(), Ids.OPEN_ACL_UNSAFE, CreateMode.PERSISTENT);
        
        Thread.sleep(2000);
        // 清理数据
        // 如果有子节点，直接删除会报错：Directory not empty for /zk_test
        // 先删除子节点
        zk.delete(path + "/c1", -1);
        zk.delete(path, -1);
        Thread.sleep(2000);
        zk.close();
        
        //----------------------------AuthInfo------------------------
        String childPath = path + "/c1";
        connectedSemaphore = new CountDownLatch(1);
        zk = new ZooKeeper("127.0.0.1:2181", 5000, sa);
        zk.addAuthInfo("digest", "key:value1".getBytes());
        connectedSemaphore.await();
        // 这里ACL和上面不同，否则加了AuthInfo也没有效果
        zk.create(path, "f".getBytes(), Ids.CREATOR_ALL_ACL, CreateMode.PERSISTENT);
        Thread.sleep(1000);
        zk.create(childPath, "c".getBytes(), Ids.CREATOR_ALL_ACL, CreateMode.PERSISTENT);
        Thread.sleep(1000);
        // 认证失败不可以删除子节点
        try
        {
            connectedSemaphore = new CountDownLatch(1);
            ZooKeeper zk2 = new ZooKeeper("127.0.0.1:2181", 5000, sa);
            connectedSemaphore.await();
            // NoAuth for /zk_test/c1
            zk2.delete(childPath, -1);
        }
        catch (Exception e)
        {
            log.info("delete node " + path + "c1" + " fail: " + e.getMessage());
        }
        
        // 认证成功可以删除子节点
        connectedSemaphore = new CountDownLatch(1);
        ZooKeeper zk3 = new ZooKeeper("127.0.0.1:2181", 5000, sa);
        connectedSemaphore.await();
        zk3.addAuthInfo("digest", "key:value1".getBytes());
        zk3.delete(childPath, -1);
        log.info("deleted node " + childPath);
        
        // 节点本身无法限制权限
        connectedSemaphore = new CountDownLatch(1);
        ZooKeeper zk4 = new ZooKeeper("127.0.0.1:2181", 5000, sa);
        connectedSemaphore.await();
        zk4.delete(path, -1);
        log.info("deleted node " + path);
        
        Thread.sleep(Integer.MAX_VALUE);
    }
    
    @Override
    public void process(WatchedEvent event)
    {
        log.info("----------------");
        log.info("event: {}", event);
        log.info("path: {}", event.getPath());
        log.info("state: {}", event.getState());
        log.info("type: {}", event.getType());
        log.info("----------------");
        try
        {
            if (KeeperState.SyncConnected == event.getState())
            {
                if (event.getType() == EventType.None && null == event.getPath())
                {
                    connectedSemaphore.countDown();
                }
                else if (event.getType() == EventType.NodeDataChanged)
                {
                    log.info(new String(zk.getData(event.getPath(), true, stat)));
                    log.info(stat.getCzxid() + "," + stat.getMzxid() + "," + stat.getVersion());
                }
                else if (event.getType() == EventType.NodeChildrenChanged)
                {
                    List<String> childrenList = zk.getChildren(path, false);
                    log.info("changed child: " + childrenList.toString());
                }
                else if (EventType.NodeCreated == event.getType())
                {
                    log.info("Node(" + event.getPath() + ")Created");
                    zk.exists(event.getPath(), true);
                }
                else if (EventType.NodeDeleted == event.getType())
                {
                    log.info("Node(" + event.getPath() + ")Deleted");
                    zk.exists(event.getPath(), true);
                }
            }
        }
        catch (Exception e)
        {
            log.error(e.toString());
        }
    }
}

异步接口：

package raw_client;

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

import org.apache.zookeeper.AsyncCallback;
import org.apache.zookeeper.CreateMode;
import org.apache.zookeeper.KeeperException;
import org.apache.zookeeper.WatchedEvent;
import org.apache.zookeeper.Watcher;
import org.apache.zookeeper.ZooKeeper;
import org.apache.zookeeper.Watcher.Event.EventType;
import org.apache.zookeeper.Watcher.Event.KeeperState;
import org.apache.zookeeper.ZooDefs.Ids;
import org.apache.zookeeper.data.Stat;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

public class AsyncApi implements Watcher
{
    
    private static CountDownLatch connectedSemaphore = new CountDownLatch(1);
    
    private static Stat stat = new Stat();
    
    static ZooKeeper zk = null;
    
    private static final Logger log = LoggerFactory.getLogger(AsyncApi.class);
    
    public static void main(String[] args) throws IOException, InterruptedException, KeeperException
    {
        zk = new ZooKeeper("127.0.0.1:2181", 5000, new AsyncApi());
        connectedSemaphore.await();
        //----------------------------创建节点------------------------
        String path = "/zk_test";
        zk.create(path, "main".getBytes(), Ids.OPEN_ACL_UNSAFE, CreateMode.PERSISTENT, new MyStringCallback(), "contex");
        
        //----------------------------获取数据------------------------
        
        zk.getData(path, true, new MYDataCallback(), null);
        
        //----------------------------更新数据------------------------
        zk.setData(path, "childdata".getBytes(), 0);
        
        //----------------------------获取子节点------------------------
        zk.create(path + "/c1",
                "child".getBytes(),
                Ids.OPEN_ACL_UNSAFE,
                CreateMode.PERSISTENT,
                new MyStringCallback(),
                "contex");
        zk.getChildren(path, true, new MyChildren2Callback(), "ctx");
        zk.getChildren(path, true, new MyChildrenCallback(), "ctx");
        
        //----------------------------删除节点------------------------
        Thread.sleep(2000);
        zk.delete(path + "/c1", -1);
        zk.delete(path, -1, new MyVoidCallback(), "ctx");
        
        Thread.sleep(Integer.MAX_VALUE);
    }
    
    @Override
    public void process(WatchedEvent event)
    {
        log.info("event: {}", event);
        log.info("path: {}", event.getPath());
        log.info("state: {}", event.getState());
        log.info("type: {}", event.getType());
        
        if (KeeperState.SyncConnected == event.getState())
        {
            if (event.getType() == EventType.None && null == event.getPath())
            {
                connectedSemaphore.countDown();
            }
            else if (event.getType() == EventType.NodeDataChanged)
            {
                try
                {
                    log.info(new String(zk.getData(event.getPath(), true, stat)));
                    log.info(stat.getCzxid() + "," + stat.getMzxid() + "," + stat.getVersion());
                }
                catch (Exception e)
                {
                }
            }
        }
    }
    
}

class MyStringCallback implements AsyncCallback.StringCallback
{
    private static final Logger log = LoggerFactory.getLogger(MyStringCallback.class);
    
    @Override
    public void processResult(int rc, String path, Object ctx, String name)
    {
        log.info("Create path result: [" + rc + ", " + path + ", " + ctx + ", real path name: " + name);
    }
}

class MyVoidCallback implements AsyncCallback.VoidCallback
{
    private static final Logger log = LoggerFactory.getLogger(MyVoidCallback.class);
    
    @Override
    public void processResult(int rc, String path, Object ctx)
    {
        log.info("delete path result: " + rc + ", " + path + ", " + ctx);
    }
}

class MYDataCallback implements AsyncCallback.DataCallback
{
    private static final Logger log = LoggerFactory.getLogger(MYDataCallback.class);
    
    @Override
    public void processResult(int rc, String path, Object ctx, byte[] data, Stat stat)
    {
        log.info(rc + ", " + path + ", " + new String(data));
        log.info(stat.getCzxid() + "," + stat.getMzxid() + "," + stat.getVersion());
    }
}

class MyChildren2Callback implements AsyncCallback.Children2Callback
{
    private static final Logger log = LoggerFactory.getLogger(MyChildren2Callback.class);
    
    @Override
    public void processResult(int rc, String path, Object ctx, List<String> children, Stat stat)
    {
        log.info("Get Children znode result: [response code: " + rc + ", param path: " + path + ", ctx: "
                + ctx + ", children list: " + children + ", stat: " + stat);
    }
}

class MyChildrenCallback implements AsyncCallback.ChildrenCallback
{
    private static final Logger log = LoggerFactory.getLogger(MyChildrenCallback.class);
    
    @Override
    public void processResult(int rc, String path, Object ctx, List<String> children)
    {
        log.info("Get Children znode result: [response code: " + rc + ", param path: " + path + ", ctx: "
                + ctx + ", children list: " + children);
    }
}