此處使用ElasticSearch6.4.2版本
SpringBoot 和ElasticSearch 環境以及 安裝ik分詞等操作不再綴訴,直接進入整合,本節不闡述原理

1. 匯入依賴
   此處使用的elasticsearch為6.4.2版本,SpringBoot 版本為2.0.6

        <dependency>
            <groupId>org.elasticsearch.client</groupId>
            <artifactId>elasticsearch-rest-high-
 
level-client</artifactId>
            <version>6.4.2</version>
        </dependency>
        <dependency>
            <groupId>org.elasticsearch</groupId>
            <artifactId>elasticsearch</artifactId>
            <version>6.4.2</version>
 

        </dependency>

2. 建立配置檔案

import org.apache.http.HttpHost;
import org.elasticsearch.client.RestClient;
import org.elasticsearch.client.RestHighLevelClient;
import org.springframework.beans.factory.annotation.Value;
import org.springframework.context.annotation.Bean;
import org.springframework.
 
context.annotation.ComponentScan;
import org.springframework.context.annotation.Configuration;
import org.springframework.context.annotation.Scope;

@Configuration
@ComponentScan(basePackageClasses=ESClientSpringFactory.class)
public class ESConfig {
    @Value("${elasticSearch.host}")
    private String host;

    @Value("${elasticSearch.port}")
    private int port;

    @Value("${elasticSearch.client.connectNum}")
    private Integer connectNum;

    @Value("${elasticSearch.client.connectPerRoute}")
    private Integer connectPerRoute;

    @Bean
    public HttpHost httpHost(){
        return new HttpHost(host,port,"http");
    }

    @Bean(initMethod="init",destroyMethod="close")
    public ESClientSpringFactory getFactory(){
        return ESClientSpringFactory.
                build(httpHost(), connectNum, connectPerRoute);
    }

    @Bean
    @Scope("singleton")
    public RestClient getRestClient(){
        return getFactory().getClient();
    }

    @Bean
    @Scope("singleton")
    public RestHighLevelClient getRHLClient(){
        return getFactory().getRhlClient();
    }

}

3. 建立clientFactory

import org.apache.http.HttpHost;
import org.elasticsearch.client.RestClient;
import org.elasticsearch.client.RestClientBuilder;
import org.elasticsearch.client.RestHighLevelClient;

import java.io.IOException;

public class ESClientSpringFactory {

    public static int CONNECT_TIMEOUT_MILLIS = 1000;
    public static int SOCKET_TIMEOUT_MILLIS = 30000;
    public static int CONNECTION_REQUEST_TIMEOUT_MILLIS = 500;
    public static int MAX_CONN_PER_ROUTE = 10;
    public static int MAX_CONN_TOTAL = 30;

    private static HttpHost HTTP_HOST;
    private RestClientBuilder builder;
    private RestClient restClient;
    private RestHighLevelClient restHighLevelClient;

    private static ESClientSpringFactory esClientSpringFactory = new ESClientSpringFactory();

    private ESClientSpringFactory(){}

    public static ESClientSpringFactory build(HttpHost httpHost,
                                              Integer maxConnectNum, Integer maxConnectPerRoute){
        HTTP_HOST = httpHost;
        MAX_CONN_TOTAL = maxConnectNum;
        MAX_CONN_PER_ROUTE = maxConnectPerRoute;
        return  esClientSpringFactory;
    }

    public static ESClientSpringFactory build(HttpHost httpHost,Integer connectTimeOut, Integer socketTimeOut,
                                              Integer connectionRequestTime,Integer maxConnectNum, Integer maxConnectPerRoute){
        HTTP_HOST = httpHost;
        CONNECT_TIMEOUT_MILLIS = connectTimeOut;
        SOCKET_TIMEOUT_MILLIS = socketTimeOut;
        CONNECTION_REQUEST_TIMEOUT_MILLIS = connectionRequestTime;
        MAX_CONN_TOTAL = maxConnectNum;
        MAX_CONN_PER_ROUTE = maxConnectPerRoute;
        return  esClientSpringFactory;
    }


    public void init(){
        builder = RestClient.builder(HTTP_HOST);
        setConnectTimeOutConfig();
        setMutiConnectConfig();
        restClient = builder.build();
        restHighLevelClient = new RestHighLevelClient(builder);
        System.out.println("init factory");
    }
    // 配置連線時間延時
    public void setConnectTimeOutConfig(){
        builder.setRequestConfigCallback(requestConfigBuilder -> {
            requestConfigBuilder.setConnectTimeout(CONNECT_TIMEOUT_MILLIS);
            requestConfigBuilder.setSocketTimeout(SOCKET_TIMEOUT_MILLIS);
            requestConfigBuilder.setConnectionRequestTimeout(CONNECTION_REQUEST_TIMEOUT_MILLIS);
            return requestConfigBuilder;
        });
    }
    // 使用非同步httpclient時設定併發連線數
    public void setMutiConnectConfig(){
        builder.setHttpClientConfigCallback(httpClientBuilder -> {
            httpClientBuilder.setMaxConnTotal(MAX_CONN_TOTAL);
            httpClientBuilder.setMaxConnPerRoute(MAX_CONN_PER_ROUTE);
            return httpClientBuilder;
        });
    }

    public RestClient getClient(){
        return restClient;
    }

    public RestHighLevelClient getRhlClient(){
        return restHighLevelClient;
    }

    public void close() {
        if (restClient != null) {
            try {
                restClient.close();
            } catch (IOException e) {
                e.printStackTrace();
            }
        }
        System.out.println("close client");
    }
}

4. 新增配置,在application.properties裡新增以下內容

elasticSearch.host=172.17.0.1
elasticSearch.port=9200
elasticSearch.client.connectNum=10
elasticSearch.client.connectPerRoute=50

至此整合完成
啟動後RestHighLevelClient 處於可用狀態
使用

@Autowired
private RestHighLevelClient rhlClient;

即可呼叫RestHighLevelClient