Elasticsearch Java Client连接池

按照Elasticsearch API，在Java端使用是ES服务需要创建Java Client，但是每一次连接都实例化一个client，对系统的消耗很大，即使在使用完毕之后将client close掉，由于服务器不能及时回收socket资源，极端情况下会导致服务器达到最大连接数。

为了解决上述问题并提高client利用率，可以参考使用池化技术复用client。

 import java.io.IOException;
 import java.net.InetSocketAddress;
 import java.util.ArrayList;
 import java.util.HashMap;
 import java.util.List;
 import java.util.Map;
 import java.util.concurrent.ConcurrentHashMap;

 import org.elasticsearch.client.Client;
 import org.elasticsearch.common.settings.Settings;
 import org.elasticsearch.common.transport.InetSocketTransportAddress;
 import org.elasticsearch.common.xcontent.XContentBuilder;
 import org.elasticsearch.common.xcontent.XContentFactory;
 import org.elasticsearch.index.mapper.Mapping;
 import org.elasticsearch.transport.client.PreBuiltTransportClient;

 import com.chinadigitalvideo.esagent.servlet.WebServiceInit;

 /**
  * Created by tgg on 16-3-17.
  */
 public class ClientHelper {
     private static String ip;
     private static int port;

     private Settings setting;
     private Mapping mapping;

     private Map<String, Client> clientMap = new ConcurrentHashMap<String, Client>();

     private Map<String, Integer> ips = new HashMap<String, Integer>(); // hostname port

     private String clusterName = WebServiceInit.clusterName;

     private ClientHelper(String ip,Integer port) {
         init(ip,port);
         //TO-DO 添加你需要的client到helper
     }

     public static final ClientHelper getInstance(String ipConf ,Integer portConf) {
         ip=ipConf;
         port=portConf;
         return ClientHolder.INSTANCE;
     }

     private static class ClientHolder {
         private static final ClientHelper INSTANCE = new ClientHelper(ip,port);
     }

     /**
      * 初始化默认的client
      */
     public void init(String ip,int port) {

         ips.put(ip, port);
         setting =Settings.builder()
                 .put("client.transport.sniff",true)
                 .put("cluster.name",clusterName).build();
         addClient(setting, getAllAddress(ips));
     }

     /**
      * 获得所有的地址端口
      *
      * @return
      */
     public List<InetSocketTransportAddress> getAllAddress(Map<String, Integer> ips) {
         List<InetSocketTransportAddress> addressList = new ArrayList<InetSocketTransportAddress>();
         for (String ip : ips.keySet()) {
             addressList.add(new InetSocketTransportAddress(new InetSocketAddress(ip, ips.get(ip))));
         }
         return addressList;
     }

     public Client getClient() {
         return getClient(clusterName);
     }

     public Client getClient(String clusterName) {
         return clientMap.get(clusterName);//通过集群名称得到一个Client
     }

     public void addClient(Settings setting, List<InetSocketTransportAddress> transportAddress) {
         Client client = new PreBuiltTransportClient(setting)
                 .addTransportAddresses(transportAddress.toArray(new InetSocketTransportAddress[transportAddress.size()]));

         clientMap.put(setting.get("cluster.name"), client);
     }
 }