Zookeeper学习2:Java编写访问的客户端 错误: 找不到或无法加载主类

代码按《ZooKeeper分布式过程协同技术详解》中编写：

需要先设置CLASSPATH ，可以在~/.bashrc 或者~/.bash_profile 中：添加:

export ZOOBINDIR=${ZOOKEEPER_HOME}/bin，ZOOKEEPER_HOME就是zookeeper的包位置

然后运行：. zkEnv.sh

　　　　　　echo $CLASSPATH 看看变化

package zkWatcher;

import org.apache.zookeeper.ZooKeeper;
import org.apache.zookeeper.CreateMode;
import org.apache.zookeeper.KeeperException;
import org.apache.zookeeper.WatchedEvent;
import org.apache.zookeeper.Watcher;
import org.apache.zookeeper.ZooDefs;

import java.io.IOException;
import java.util.Random;

public class Master implements Watcher{

    ZooKeeper zk;
    String hostPort;
    
    Master(String hostPort){
        this.hostPort = hostPort;
    }
    
    void startZK() throws IOException {
        zk = new ZooKeeper(hostPort,15000,this);
        try {
            runForMaster();
        } catch (KeeperException e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
        } catch (InterruptedException e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
        }
    }
    
    void closeZK() throws InterruptedException {
        zk.close();
    }
    
    void runForMaster() throws KeeperException, InterruptedException {
        Random rand = new Random();
        String serverId = Integer.toHexString(rand.nextInt()) ;
        zk.create("/master", serverId.getBytes(),ZooDefs.Ids.OPEN_ACL_UNSAFE, CreateMode.EPHEMERAL );
    }
    
    public static void main(String[] args) throws Exception {
        // TODO Auto-generated method stub
        Master m = new Master(args[0]);
        
        m.startZK();
        
        System.out.println("load");
        Thread.sleep(10000);
        //m.closeZK();
    }

    @Override
    public void process(WatchedEvent event) {
        // TODO Auto-generated method stub
        System.out.println(event);
    }
}

编译的时候在zkWatcher 目录下面：javac -cp $CLASSPATH Master.java 

可以正常生成Master.class 文件

运行:javac -cp $CLASSPATH Master 127.0.0.1:2181

时会报：错误: 找不到或无法加载主类 Master

这个时候因为 Master.java带了包名，回退到上一级目录就可以通过了

java -cp $CLASSPATH zkWatcher/Master 127.0.0.1:2181