java连接elastic search 9300

java连接elastic search

导入jar包：https://www.elastic.co/guide/en/elasticsearch/client/java-api/5.5/_maven_repository.html

注意，使用的jar包版本尽量与所连的els版本一致

创建连接：https://www.elastic.co/guide/en/elasticsearch/client/java-api/5.5/transport-client.html

查询：https://www.elastic.co/guide/en/elasticsearch/client/java-api/5.5/java-search.html

发现两个错误：

ERROR StatusLogger Log4j2 could not find a logging implementation. Please add log4j-core to the classpath. Using SimpleLogger to log to the console...

错误原因：java连接els用到了log4j2，所以需要log4j2-core的依赖

解决办法：添加log4j2-core依赖

https://www.elastic.co/guide/en/elasticsearch/client/java-api/5.5/_log4j_2_logger.html

NoNodeAvailableException[None of the configured nodes are available: [{#

错误原因：创建连接时需要配置cluster_name。

elasticsearch服务器的cluster_name可以在#els_home#/config/elasticsearch.yml文件中配置。

然后在java客户端程序中将

TransportClient client=new PreBuiltTransportClient(Settings.EMPTY).addTransportAddress(new InetSocketTransportAddress(InetAddress.getByName("139.199.32.101"),9300));

改为

Settings settings=Settings.builder().put("cluster.name","production").build();
TransportClient client=new PreBuiltTransportClient(settings).addTransportAddress(new InetSocketTransportAddress(InetAddress.getByName("139.199.32.101"),9300));

JAVA客户端代码：

package com.tpot.DataDownload;

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

//import org.elasticsearch.action.bulk.BulkRequestBuilder;
import org.elasticsearch.action.search.SearchResponse;
import org.elasticsearch.client.Client;
import org.elasticsearch.client.transport.TransportClient;
import org.elasticsearch.common.settings.Settings;
//import org.elasticsearch.common.transport.TransportAddress;
import org.elasticsearch.common.transport.InetSocketTransportAddress;
import org.elasticsearch.transport.client.PreBuiltTransportClient;

/**
 * Hello world!
 *
 */
public class App
{
    public static void main( String[] args ) throws UnknownHostException
    {
        System.out.println( "Hello World!" );

        //连接+配置
        Settings settings=Settings.builder().put("cluster.name","production").build();
        TransportClient client=new PreBuiltTransportClient(settings).addTransportAddress(new InetSocketTransportAddress(InetAddress.getByName("139.xxx.xxx.101"),9300));

        //查询
        SearchResponse response = client.prepareSearch().get();
        System.out.println(response);

        //关闭连接
        client.close();
    }
}

pom.xml文件中添加的依赖：

  <dependency>
      <groupId>org.elasticsearch.client</groupId>
      <artifactId>transport</artifactId>
      <version>5.5.3</version>
  </dependency>

<dependency>
  <groupId>org.apache.logging.log4j</groupId>
  <artifactId>log4j-core</artifactId>
  <version>2.8.2</version>
</dependency>