Zookeeper作数据存储

/**
 * 这是一简单的接口类
 * @author tianji
 *
 */

public interface ZookeeperService {

    void create(String path, byte[] data, boolean ephemeral);

    byte[] getData(String path);

    String getConfigData(String path);

    void setData(String path, byte[] data) throws Exception;

    void delete(String path);

    List<String> getChildren(String path);

    boolean checkExists(String path, String activityCategory, String pathType) throws Exception;

}

/**
 * 这是接口的实现类
 * @author tianji
 *
 */

 

 

import org.apache.commons.lang.StringUtils;

import org.apache.commons.logging.Log;

import org.apache.commons.logging.LogFactory;

import org.apache.curator.framework.CuratorFramework;

import org.apache.curator.framework.CuratorFrameworkFactory;

import org.apache.curator.retry.ExponentialBackoffRetry;

import org.apache.zookeeper.CreateMode;

import org.springframework.context.annotation.Lazy;

import org.springframework.stereotype.Service;

 

public class ZookeeperServiceImpl implements ZookeeperService{

 

    private static final int CONNECTIONTIMEOUTMS = 15000;

    private static final int SESSIONTIMEOUTMS = 60000;

    privatefinal int BASESLEEPTIMEMS = 1000;

    private static final int MAXRETRIES = 3;

    private static final int MAXSLEEPMS = 5000;

    private CuratorFramework client;

 

    //在此笔者使用的是CuratorFramework,是一款ZooKeeper客户端工具，封装了大量的    zookeeper api

    //在创建这个类时就调用此构造方法连接zookeeper服务器

   //并设置相关的zookeeper参数

 

    public ZookeeperServiceImpl(){

        this.client = CuratorFrameworkFactory.builder()

                          .connectString(“192.168.1.111:2181”)

                          .connectionTimeoutMs(CONNECTIONTIMEOUTMS)

                         .sessionTimeoutMs(SESSIONTIMEOUTMS)

                         .retryPolicy(new ExponentialBackoffRetry(BASESLEEPTIMEMS, MAXRETRIES,                                                                                                             MAXSLEEPMS))

                         .build();

    }

 

 

   //在zookeeper服务器上创建节点

   //当 ephemeral 为 true 创建永久节点，为false时创建临时节点(当此连接断开时，即自动删除)

   @Override

    public void create(String path, byte[] data, boolean ephemeral) {

        if(data == null || data.length == 0) {

data = new byte[0];

}

        try {

if(client == null || ! client.getZookeeperClient().isConnected()){

client.start();

}

if(ephemeral) {

client.create().creatingParentsIfNeeded().withMode(CreateMode.PERSISTENT).forPath(path, data);

} else {

client.create().creatingParentsIfNeeded().forPath(path, data);

}

} catch(Exception e) {

e.printStackTrace();

throw new IllegalStateException(e.getMessage());

}

    }

    //检查服务器上是否存在某个节点

    @Override

public boolean checkExists(String path, String activityCategory, String pathType) throws Exception {

if(client == null || ! client.getZookeeperClient().isConnected()){

client.start();

}

                if(client.checkExists().forPath(path) == null){

                                           this.client.create().creatingParentsIfNeeded().withMode(CreateMode.PERSISTENT).forPath(path, new byte[0]);

                }

                if(client.checkExists().forPath(path) == null){

return false;

}else{

return true;

}

        }

 

       //获取某个节点的数据

       @Override

public byte[] getData(String path) {

if(client == null || ! client.getZookeeperClient().isConnected()){

client.start();

}

try {

if(client.checkExists().forPath(path) == null){

return new byte[0];

}else{

return client.getData().forPath(path);

}

} catch(Exception e) {

throw new IllegalStateException(e.getMessage());

}

}

 

       //设置某个节点的数据

       @Override

public void setData(String path, byte[] data) {

if(client == null || ! client.getZookeeperClient().isConnected()){

client.start();

}

try {

if(data == null || data.length == 0) {

data = new byte[0];

}

 

client.setData().forPath(path, data);

} catch(Exception e) {

e.printStackTrace();

throw new IllegalStateException(e.getMessage());

}

}

 

        //删除某个节点

         @Override

public void delete(String path) {

if(client == null || ! client.getZookeeperClient().isConnected()){

client.start();

}

try {

client.delete().forPath(path);

} catch(Exception e) {

throw new IllegalStateException(e.getMessage());

}

}

        //获取某个节点下的所有子节点

        @Override

public List<String> getChildren(String path) {

if(client == null || ! client.getZookeeperClient().isConnected()){

client.start();

}

try {

return client.getChildren().forPath(path);

} catch(Exception e) {

throw new IllegalStateException(e.getMessage());

}

}

 

}