使用java客户端操作elasticsearch

使用java客户端操作elasticsearch

本文主要参考：

https://www.elastic.co/guide/en/elasticsearch/client/java-api/current/index.html

本文的主要目的不是追求如何用java语言进行elasticsearch的操作，而是如何搭建一个环境，这个环境能够进行访问elasticsearch。

好，下面上货。

1、首先新建一个简单maven项目。

mvn archetype:generate -DarchetypeCatalog=internal

2、然后修改pom文件，添加依赖。

            org.elasticsearch.client
            transport
            5.2.2
        

        
            org.apache.logging.log4j
            log4j-api
            2.7
        
        
            org.apache.logging.log4j
            log4j-core
            2.7
        

添加plugins查看，方便打jar包。

            
                org.apache.maven.plugins
                maven-compiler-plugin
                
                    1.8
                    1.8
                    utf-8
                
            
            
                maven-assembly-plugin
                3.0.0
                
                    
                        
                            com.xueyouc.xueyou.App
                        
                    
                    
                        jar-with-dependencies
                    
                
                
                    
                        make-assembly 
                        package 
                        
                            single
                        
                    
                
            
        

3、添加log4j2的配置文件和本地配置文件

log4j2.properties：

appender.console.type = Console
appender.console.name = console
appender.console.layout.type = PatternLayout

rootLogger.level = info
rootLogger.appenderRef.console.ref = console

conf.properties：

elasticsearch.clustername=xycluster
elasticsearch.addr1=127.0.0.1

4、编写程序实现对elasticsearch的访问：

App.java

package com.xueyouc.xueyou;

import org.elasticsearch.action.index.IndexResponse;
import org.elasticsearch.client.transport.TransportClient;
import org.elasticsearch.common.settings.Settings;
import org.elasticsearch.common.transport.InetSocketTransportAddress;
import org.elasticsearch.common.xcontent.XContentBuilder;
import org.elasticsearch.transport.client.PreBuiltTransportClient;

import java.io.IOException;
import java.net.InetAddress;
import java.net.UnknownHostException;
import java.util.Date;
import java.util.ResourceBundle;

import static org.elasticsearch.common.xcontent.XContentFactory.jsonBuilder;

/**
 * Hello world!
 */
public class App {
    public static void main(String[] args) {
        /**
         * 读取配置文件
         */
        ResourceBundle rb = ResourceBundle.getBundle("conf");
        String clustername = rb.getString("elasticsearch.clustername");
        String addr1 = rb.getString("elasticsearch.addr1");

        String[] temparray = addr1.split("\\.");
        byte[] localAddr = new byte[temparray.length];
        for (int i = 0; i < temparray.length; i++) {
            localAddr[i] = Byte.parseByte(temparray[i]);
        }

        TransportClient client = null;
        try {
            Settings settings = Settings.builder().put("cluster.name", clustername).build();
            client = new PreBuiltTransportClient(settings)
                    .addTransportAddress(new InetSocketTransportAddress(InetAddress.getByAddress(localAddr), 9300));
            //插入你的处理逻辑

            try {
                XContentBuilder builder = jsonBuilder().startObject().field("user", "user002").field("postDate", new Date()).field("message", "trying out elasticsearch").endObject();
                IndexResponse response = client.prepareIndex("testindex","testtype","2").setSource(builder).execute().actionGet();

                System.out.println("============================");
                System.out.println(response.getIndex());
                System.out.println(response.getType());
                System.out.println(response.getId());
                System.out.println("============================");
            } catch (IOException e) {
                e.printStackTrace();
            } finally {
            }


        } catch (UnknownHostException e) {
            e.printStackTrace();
        } finally {
            client.close();
        }


    }
}

上面的代码需要优化：

localAddr[i] = (byte) Integer.parseInt(temparray[i]);

5、运行结果：

6、检索elasticsearch中的数据