Java连接Elasticsearch集群

Posted 2020-06-16

package cn.test;

import java.net.InetAddress;
import java.net.UnknownHostException;

import org.elasticsearch.client.transport.TransportClient;
import org.elasticsearch.common.settings.Settings;
import org.elasticsearch.common.transport.InetSocketTransportAddress;
public class ElkTest {
//  private static final String CLUSTER_NAME = "cluster_name";  
    public static final String CLUSTER_NAME = "elasticsearch"; //实例名称
//  private static final String IP = "127.0.0.1";  
    private static final String IP = "192.168.0.29";  
    private static final int PORT = 9200;  //端口
    //1.设置集群名称：默认是elasticsearch，并设置client.transport.sniff为true，使客户端嗅探整个集群状态，把集群中的其他机器IP加入到客户端中  
    /* 
    //对ES1.6有效 
    private static Settings settings = ImmutableSettings 
            .settingsBuilder() 
            .put("cluster.name",CLUSTER_NAME) 
            .put("client.transport.sniff", true) 
            .build(); 
    */  
    //对ES2.0有效  
    private static Settings settings = Settings  
            .settingsBuilder()  
            .put("cluster.name",CLUSTER_NAME)  
            .put("client.transport.sniff", true)  
            .build();  
    //创建私有对象  
    private static TransportClient client;  
  
    //反射机制创建单例的TransportClient对象  ES1.6版本  
//    static {  
//        try {  
//            Class<?> clazz = Class.forName(TransportClient.class.getName());  
//            Constructor<?> constructor = clazz.getDeclaredConstructor(Settings.class);  
//            constructor.setAccessible(true);  
//            client = (TransportClient) constructor.newInstance(settings);  
//            client.addTransportAddress(new InetSocketTransportAddress(InetAddress.getByName(IP), PORT));  
//        } catch (Exception e) {  
//            e.printStackTrace();  
//        }  
//    }  
  
    //ES2.0版本  
    static {  
        try {  
            client = TransportClient.builder().settings(settings).build()  
                    .addTransportAddress(new InetSocketTransportAddress(InetAddress.getByName(IP), PORT));  
        } catch (UnknownHostException e) {  
            e.printStackTrace();  
        }  
    }  
  
    //取得实例  
    public static synchronized TransportClient getTransportClient(){  
        return client;  
    }  
  
    //为集群添加新的节点  
    public static synchronized void addNode(String name){  
        try {  
            client.addTransportAddress(new InetSocketTransportAddress(InetAddress.getByName(name),9300));  
        } catch (UnknownHostException e) {  
            e.printStackTrace();  
        }  
    }  
  
    //删除集群中的某个节点  
    public static synchronized void removeNode(String name){  
        try {  
            client.removeTransportAddress(new InetSocketTransportAddress(InetAddress.getByName(name),9300));  
        } catch (UnknownHostException e) {  
            e.printStackTrace();  
        }  
    }  
    public static void main(String args[]){  
        getTransportClient();  
    }  
}