Springboot 操作Elasticsearch 方式二 【rest-high-level-client】

　　操作环境：win10+elasticsearch7.11.1 ,springboot2.1.8+elasticsearch6.7.1客户端

　　elasticsearch版本是向下兼容的，也就是elasticsearch安装的版本比较高，使用springboot连接ES时，版本低一些也是可以正常使用的

　　springboot集成ES，对应版本查询https://docs.spring.io/spring-data/elasticsearch/docs/current/reference/html/#preface.versions

　　整体目录结构

• 　pom.xml文件添加依赖

    <properties>
        <java.version>1.8</java.version>
        <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
        <project.reporting.outputEncoding>UTF-8</project.reporting.outputEncoding>
        <spring-boot.version>2.1.8.RELEASE</spring-boot.version>
        <elasticsearch.version>6.7.1</elasticsearch.version>
    </properties>

 <dependencies>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-web</artifactId>
        </dependency>
        <!-- https://mvnrepository.com/artifact/org.elasticsearch/elasticsearch -->
        <dependency>
            <groupId>org.elasticsearch</groupId>
            <artifactId>elasticsearch</artifactId>
            <version>${elasticsearch.version}</version>
        </dependency>
        <dependency>
            <groupId>org.elasticsearch.client</groupId>
            <artifactId>elasticsearch-rest-high-level-client</artifactId>
            <version>${elasticsearch.version}</version>
        </dependency>
 </dependencies>

• application.yml添加如下配置

server:
  port: 8080
spring:
  application:
    name: resthighclient
#es http方式
elasticsearch:
  hostname:  127.0.0.1
  port: 9200
  scheme: http
  connTimeout: 1000
  socketTimeout: 3000
  connectionRequestTimeout: 500
  username: elastic
  password: 123456

• 创建连接配置类RestClientConfig

package com.example.resthighclient.config;

import org.apache.http.HttpHost;
import org.apache.http.auth.AuthScope;
import org.apache.http.auth.UsernamePasswordCredentials;
import org.apache.http.client.CredentialsProvider;
import org.apache.http.impl.client.BasicCredentialsProvider;
import org.elasticsearch.client.RestClient;
import org.elasticsearch.client.RestClientBuilder;
import org.elasticsearch.client.RestHighLevelClient;
import org.springframework.beans.factory.annotation.Value;
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;

@Configuration
public class RestClientConfig   {

    @Value("${elasticsearch.hostname}")
    private  String hostname;

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

    @Value("${elasticsearch.connTimeout}")
    private int connTimeout;

    @Value("${elasticsearch.socketTimeout}")
    private int socketTimeout;

    @Value("${elasticsearch.connectionRequestTimeout}")
    private int connectionRequestTimeout;

    @Value("${elasticsearch.username}")
    private String username;

    @Value("${elasticsearch.password}")
    private String password;

    /*
      HighLevelRestConfig
     */
    @Bean(destroyMethod = "close", name = "client")
    public RestHighLevelClient restHighLevelClient(){

        CredentialsProvider credentialsProvider = new BasicCredentialsProvider();
        credentialsProvider.setCredentials(AuthScope.ANY, new UsernamePasswordCredentials(username,password));

        RestClientBuilder builder = RestClient.builder(new HttpHost(hostname, port))
                .setRequestConfigCallback(requestConfigBuilder -> requestConfigBuilder
                        .setConnectTimeout(connTimeout)
                        .setSocketTimeout(socketTimeout)
                        .setConnectionRequestTimeout(connectionRequestTimeout)
                ).setHttpClientConfigCallback(f->f.setDefaultCredentialsProvider(credentialsProvider));//带密码的ES连接访问
        return new RestHighLevelClient(builder);
    }
}

• 创建索引常量

package com.example.resthighclient.constant;

public interface   Constant {

    String INDEX = "book";
}

• 创建接口访问controller类

package com.example.resthighclient.controller;

import com.alibaba.fastjson.JSON;
import com.example.resthighclient.constant.Constant;
import com.example.resthighclient.model.Book;
import com.example.resthighclient.model.response.Result;
import lombok.extern.slf4j.Slf4j;
import org.elasticsearch.action.get.GetRequest;
import org.elasticsearch.action.get.GetResponse;
import org.elasticsearch.action.index.IndexRequest;
import org.elasticsearch.action.index.IndexResponse;
import org.elasticsearch.action.search.SearchRequest;
import org.elasticsearch.action.search.SearchResponse;
import org.elasticsearch.client.RequestOptions;
import org.elasticsearch.client.RestHighLevelClient;
import org.elasticsearch.client.indices.GetIndexRequest;
import org.elasticsearch.common.xcontent.XContentType;
import org.elasticsearch.index.query.MatchPhrasePrefixQueryBuilder;
import org.elasticsearch.index.query.QueryBuilders;
import org.elasticsearch.search.builder.SearchSourceBuilder;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.beans.factory.annotation.Qualifier;
import org.springframework.util.StringUtils;
import org.springframework.web.bind.annotation.*;

import javax.annotation.Resource;
import java.io.IOException;
import java.util.Date;
import java.util.UUID;

@RestController
@RequestMapping("/api/high")
@Slf4j
public class HighLevelRestController {
    /**
     * logger
     */
    private static final Logger logger = LoggerFactory.getLogger(HighLevelRestController.class);


    @Resource
    private RestHighLevelClient restHighLevelClient;

    /*
    获取ES信息
     */
    @GetMapping("es")
    public Result getEsInfo() throws IOException {

        SearchSourceBuilder searchSourceBuilder = new SearchSourceBuilder();
        SearchRequest searchRequest = new SearchRequest();
        searchRequest.source(searchSourceBuilder);
        //查询ES
        SearchResponse searchResponse = restHighLevelClient.search(searchRequest, RequestOptions.DEFAULT);
        return Result.SUCCESS(searchResponse);
    }

    //保存数据
    @PostMapping("save")
    public Result save(@RequestBody Book book)  throws IOException  {
        if (book == null || StringUtils.isEmpty(book.getTitle())) {
            return Result.FAIL("标题不能为空");
        } else if (StringUtils.isEmpty(book.getContent())) {
            return Result.FAIL("内容不能为空");
        }
        UUID uuid= UUID.randomUUID();
        book.setId(uuid.toString());
        book.setCreateTime(new Date());

        IndexRequest indexRequest = new IndexRequest(Constant.INDEX,"_doc","id")
                .id(book.getId())
                .source(JSON.toJSONString(book), XContentType.JSON);
        IndexResponse indexResponse = restHighLevelClient.index(indexRequest, RequestOptions.DEFAULT);
        if (indexResponse.getId() != null)
            return Result.SUCCESS("保存成功");
        else
            return Result.FAIL("保存失败");
    }

    //判断索引是否存在
        @GetMapping("isExist")
    public boolean isIndexExists(String index) throws  IOException{
        GetIndexRequest request = new GetIndexRequest();
        request.indices();
        request.local(false);
        request.humanReadable(true);
        boolean exists  = restHighLevelClient.indices().exists(request,RequestOptions.DEFAULT) ;
        return exists;
    }



    /*
    根据id查询
     */
    @GetMapping("getById")
    public Result getById(String id) throws IOException {
        GetRequest getRequest=new GetRequest(Constant.INDEX,"_doc", id);
        //查询ES
        GetResponse getResponse = restHighLevelClient.get(getRequest, RequestOptions.DEFAULT);

        if (getResponse.isExists()) {
            String sourceAsString = getResponse.getSourceAsString();
             return   Result.SUCCESS(getResponse.getSourceAsString());
        } else {
            logger.error("没有找到该 id 的文档");
            return Result.FAIL("没有找到该 id 的文档");
        }
    }
}

• 创建book索引类实体

package com.example.resthighclient.model;

import lombok.Data;
import java.io.Serializable;
import java.util.Date;

//通过这个注解，可以不用写gettersetter方法
@Data
public class Book implements Serializable {

    private String id;

    private String title;

    private String content;

    private Integer userId;

    private Date createTime;


}

• 使用postman工具，进行接口测试