Java API connects Elasticsearch cluster

写在前面

org.elasticsearch.client
transport&elasticsearch-rest-high-level-client

官网地址：

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

方式一：TransportClient

pom.xml

        <!--添加Es的dependency-->
        <!-- https://mvnrepository.com/artifact/org.elasticsearch.client/transport -->
        <dependency>
            <groupId>org.elasticsearch.client</groupId>
            <artifactId>transport</artifactId>
            <version>6.2.4</version>
        </dependency>

代码：

package com.sunshine.punch.es;

import org.elasticsearch.action.get.GetResponse;
import org.elasticsearch.action.get.MultiGetItemResponse;
import org.elasticsearch.action.get.MultiGetResponse;
import org.elasticsearch.action.index.IndexResponse;
import org.elasticsearch.client.Response;
import org.elasticsearch.client.transport.TransportClient;
import org.elasticsearch.common.settings.Settings;
import org.elasticsearch.common.transport.TransportAddress;
import org.elasticsearch.common.xcontent.XContentBuilder;
import org.elasticsearch.common.xcontent.XContentType;
import org.elasticsearch.transport.client.PreBuiltTransportClient;
import org.junit.After;
import org.junit.Before;
import org.junit.Test;

import java.io.IOException;
import java.net.InetAddress;
import java.net.UnknownHostException;
import java.util.HashMap;
import java.util.Map;

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

/**
 * Description:
 *
 * Settings
 * Client/PreBuiltTransportClient
 * client.admin().indices().prepareCreate(INDEX).get();
 * client.admin().indices().prepareDelete(INDEX).get();
 * prepareIndex
 * prepareGet
 * prepareMultiGet
 * get()
 * Hadoop : HDFS + YARN 【生产上主要使用Hadoop的点】
 *         YARN:能够提交Spark等作业上去就行了 Spark on YARN
 *         HDFS:单纯的用来存储数据就好
 *
 * @Author: 留歌36
 * @Date: 2019/5/23 9:55
 */
public class TransportAddressApp {
    TransportClient client;
    @Before
    public void setUp(){
        // 设置集群名称
        Settings settings = Settings.builder().put("cluster.name", "tongnan-application").build();
        // 创建client
        try {
            client = new PreBuiltTransportClient(settings)
                    .addTransportAddress(new TransportAddress(InetAddress.getByName("192.168.1.109"),9300));
        } catch (UnknownHostException e) {
            e.printStackTrace();
        }
    }
    @After
    public void  tearDown(){
        client.close();
    }

    private static final String INDEX = "street";
    private static final String TYPE ="doc";

    /**
     * 创建一个索引
     * 默认是：5个分片
     */
    @Test
    public void createIndex(){
        client.admin().indices().prepareCreate(INDEX).get();
    }

    /**
     * 删除一个索引
     */
    @Test
    public void deleteIndex(){
        client.admin().indices().prepareDelete(INDEX).get();
    }

    /**
     * 删除Doc
     */
    @Test
    public  void  deleteDoc(){

        client.prepareDelete(INDEX, TYPE, "1001").get();

    }


    /**
     * 使用Json数据创建一个文档
     * 不推荐
     */
    @Test
    public void createDocWithJson(){
        String json = "{"name":"留歌2"}";
        IndexResponse response =client.prepareIndex(INDEX, TYPE, "1001")
                .setSource(json, XContentType.JSON)
                .get();

        printInfo(response);
    }

    /**
     * 把打印的方法抽取出来
     * @param response
     */
    private void printInfo(IndexResponse response){
        System.out.println("index: "+response.getIndex());
        System.out.println("type: "+response.getType());
        System.out.println("id: "+response.getId());
        System.out.println("version: "+response.getVersion());
        System.out.println("result: "+response.getResult());
    }

    /**
     * 使用Map进行构建DOC
     * 推荐
     */
    @Test
    public void createDocWithMap(){
        Map<String,Object> map = new HashMap<>();
        map.put("street","留歌街道");
        IndexResponse response = client.prepareIndex(INDEX, TYPE, "1003")
                .setSource(map)
                .get();

        printInfo(response);
    }
    /**
     * 使用XContentBuilder进行构建DOC
     * ES提供的
     * 推荐
     */
    @Test
    public void createDocWithXContentBuilder() throws IOException {
        XContentBuilder builder = jsonBuilder()
                .startObject()
                .field("name","留歌的网站")
                .field("content","主要是一些日常Vlog")
                .field("url","www.csyh.cn")
                .endObject();
        IndexResponse response = client.prepareIndex(INDEX, TYPE, "1003")
                .setSource(builder)
                .get();

        printInfo(response);

    }

    /**
     * 查询Doc数据【单个】
     */
    @Test
    public void getDocById(){
       GetResponse response = client.prepareGet(INDEX, TYPE, "1003").get();

        System.out.println(response.getSourceAsString());
    }
    /**
     * 查询Docs数据【多个】
     */
    @Test
    public void getDocsByIds(){
        MultiGetResponse responses = client.prepareMultiGet()
                .add(INDEX, TYPE, "1003")
                .add(INDEX, TYPE, "1001","1002","1002222") // 这里的可变参数 是可以多个ID的
                .get();

        for (MultiGetItemResponse response : responses){
            GetResponse res = response.getResponse();
            if (res.isExists()){
                System.out.println(res.getSourceAsString());
            }
        }
    }
}

方式二：TransportClient

pom.xml

      <dependency>
            <groupId>org.elasticsearch.client</groupId>
            <artifactId>elasticsearch-rest-high-level-client</artifactId>
            <version>6.5.4</version>
        </dependency>

代码：

package com.sunshine.punch.es;

import org.apache.http.HttpHost;
import org.elasticsearch.action.bulk.BulkItemResponse;
import org.elasticsearch.action.bulk.BulkRequest;
import org.elasticsearch.action.bulk.BulkResponse;
import org.elasticsearch.action.get.GetRequest;
import org.elasticsearch.action.index.IndexRequest;
import org.elasticsearch.client.RequestOptions;
import org.elasticsearch.client.RestClient;
import org.elasticsearch.client.RestHighLevelClient;
import org.elasticsearch.common.xcontent.XContentType;
import org.junit.After;
import org.junit.Before;
import org.junit.Test;

import java.io.IOException;

/**
 * Description: TODO
 *
 * @Author: 留歌36
 * @Date: 2019/5/24 8:50
 */
public class HighLevelRestClientApp {
    RestHighLevelClient client;
    @Before
    public void setUp(){
        client = new RestHighLevelClient(RestClient.builder(
                new HttpHost("192.168.1.109",9200,"http")
        ));

    }
    @After
    public void tearDown(){
        try {
            client.close();
        } catch (IOException e) {
            e.printStackTrace();
        }
    }
    @Test
    public void getClient(){
        System.out.println(client);
    }
    private final String INDEX = "street";
    private final String TYPE = "doc";


    /**
     * 判断文档是否存在
     */
    @Test
    public void existDoc() throws IOException{
        GetRequest request = new GetRequest(INDEX, TYPE, "1001");
        boolean exists = client.exists(request, RequestOptions.DEFAULT);
        System.out.println("是否存在：" + exists);
    }

    /**
     * 创建Doc
     *
     */
    @Test
    public void createDoc(){

    }
    /**
     * get Doc
     *
     */
    @Test
    public void getDoc(){

    }
    /**
     * 批量Doc
     *
     */
    @Test
    public void bulkDoc() throws IOException{
        BulkRequest request = new BulkRequest();
        request.add(new IndexRequest(INDEX,TYPE).id("1004")
                .source(XContentType.JSON,"street", "测试镇1"));
        request.add(new IndexRequest(INDEX,TYPE).id("1004")
                .source(XContentType.JSON,"street", "测试镇2"));



        // 同步执行
        BulkResponse bulkResponse = client.bulk(request, RequestOptions.DEFAULT);
        if (bulkResponse.hasFailures()) {
            for (BulkItemResponse bulkItemResponse : bulkResponse) {
                if (bulkItemResponse.isFailed()) {
                    BulkItemResponse.Failure failure = bulkItemResponse.getFailure();
                    System.out.println(failure.getMessage());
                }
            }
        }



    }
    /**
     * Kibana
     * 1.全链路监控
     * 2.ak分词
     * 3.es-sql 插件
     */

}