原创2020-05-29发表2022-04-13更新SpringBoot9 分钟读完 (大约1420个字)0次访问

SpringBoot集成ES

版权申明：本文为原创文章，转载请注明原文出处

原文链接：https://blog.ye186.top/posts/52687060.html

elasticsearch被广泛用于分布式的全文检索，本文将介绍如何在Spring Boot项目中集成使用ES

软件版本信息

SpringBoot：2.3.0.RELEASE
elasticsearch：7.6.2
ik分词器：7.6.2

注意：ik分词器的版本必须和ES版本保持一致，否则会启动报错的。

创建Spring Boot项目

利用IDEA创建Spring Boot项目，选择如下三个依赖Lombok（可选）、Web、ES

或者也可以用手动添加pom依赖：

<?xml version="1.0" encoding="UTF-8"?>
<project xmlns="http://maven.apache.org/POM/4.0.0"
  xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
  xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 https://maven.apache.org/xsd/maven-4.0.0.xsd">
  <modelVersion>4.0.0</modelVersion>
  <parent>
    <groupId>org.springframework.boot</groupId>
    <artifactId>spring-boot-starter-parent</artifactId>
    <version>2.3.0.RELEASE</version>
    <relativePath/> <!-- lookup parent from repository -->
  </parent>
  <groupId>com.itf.demo</groupId>
  <artifactId>spring-boot-demo-es</artifactId>
  <version>1.0.0</version>
  <name>spring-boot-demo-es</name>
  <description>Spring Boot 集成ES</description>

  <properties>
    <java.version>1.8</java.version>
  </properties>

  <dependencies>
    <dependency>
      <groupId>org.springframework.boot</groupId>
      <artifactId>spring-boot-starter-data-elasticsearch</artifactId>
    </dependency>
    <dependency>
      <groupId>org.springframework.boot</groupId>
      <artifactId>spring-boot-starter-web</artifactId>
    </dependency>

    <dependency>
      <groupId>org.projectlombok</groupId>
      <artifactId>lombok</artifactId>
      <optional>true</optional>
    </dependency>
    <dependency>
      <groupId>org.springframework.boot</groupId>
      <artifactId>spring-boot-starter-test</artifactId>
      <scope>test</scope>
      <exclusions>
        <exclusion>
          <groupId>org.junit.vintage</groupId>
          <artifactId>junit-vintage-engine</artifactId>
        </exclusion>
      </exclusions>
    </dependency>
  </dependencies>

  <build>
    <plugins>
      <plugin>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-maven-plugin</artifactId>
      </plugin>
    </plugins>
  </build>

</project>

指定ES集群

Elasticsearch 7中TransportClient被标记为了过时，并且未来就在Elasticsearch 8中移除，官网强烈推荐我们使用High Level REST Client来连接到ES集群（参考官网文档：官网说明）。所以我们不推荐使用过时的spring.data.elasticsearch.cluster-name来指定ES集群，而是使用Java Bean的方式来创建一个连接ES的客户端。创建一个EsConfig类，内容如下：

package com.itf.demo.es;

import org.elasticsearch.client.RestHighLevelClient;
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;
import org.springframework.data.elasticsearch.client.ClientConfiguration;
import org.springframework.data.elasticsearch.client.RestClients;

/**
 * ES rest客户端配置
 *
 * @author ye17186
 * @date 2020-05-26
 */
@Configuration
public class EsConfig {

  @Bean
  public RestHighLevelClient client() {
    // ES默认端口为9200  
    ClientConfiguration clientConfig = ClientConfiguration.builder().connectedTo("127.0.0.1:9200").build();
    return RestClients.create(clientConfig).rest();
  }
}

到此，我们的Spring Boot就完成了ES的集成。

ES相关操作功能

创建一个EsDemoController，提供创建索引、新建文档、检索文档三个功能。内容如下：

package com.itf.demo.es;

import java.io.IOException;
import java.util.ArrayList;
import java.util.HashMap;
import java.util.List;
import java.util.Map;
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.CreateIndexRequest;
import org.elasticsearch.client.indices.CreateIndexResponse;
import org.elasticsearch.common.settings.Settings;
import org.elasticsearch.index.query.MultiMatchQueryBuilder;
import org.elasticsearch.search.builder.SearchSourceBuilder;
import org.elasticsearch.search.fetch.subphase.highlight.HighlightBuilder;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.core.io.ClassPathResource;
import org.springframework.web.bind.annotation.PutMapping;
import org.springframework.web.bind.annotation.RequestBody;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RestController;

/**
 * @author ye17186
 * @date 2020-05-27
 */
@RestController
@RequestMapping("/es")
public class EsDemoController {


  /**
   * ik分词器配置文件
   */
  private static final String IK_SETTINGS_FILE = "es-index-settings-ik.yml";

  private static final String DOC_FIELD_TITLE = "title";
  private static final String DOC_FIELD_CONTENT = "content";
  private static final String DOC_FIELD_DESCRIPTION = "description";

  private static final String HIGHLIGHT_PRE_TAG = "<span class=\"highlight\">";
  private static final String HIGHLIGHT_POST_TAG = "</span>";

  @Autowired
  RestHighLevelClient client;

  /**
   * 创建索引
   *
   * @param addIndexRequest 请求体
   * @return 创建结果
   * @throws IOException es异常
   */
  @PutMapping("/index")
  public CreateIndexResponse index(@RequestBody AddIndexRequest addIndexRequest) throws IOException {

    CreateIndexRequest request = new CreateIndexRequest(addIndexRequest.getIndex());
    if (addIndexRequest.getIk()) {
      Settings settings = Settings.builder().loadFromStream(IK_SETTINGS_FILE, new ClassPathResource(IK_SETTINGS_FILE).getInputStream(), true).build();
      request.settings(settings);
    }
    return client.indices().create(request, RequestOptions.DEFAULT);
  }

  /**
   * 新建一个文档
   *
   * @param addRequest 请求体
   * @return 新建结果
   * @throws IOException es异常
   */
  @PutMapping("/doc")
  public AddDocResponse doc(@RequestBody AddDocRequest addRequest) throws IOException {

    Map<String, String> doc = new HashMap<>();
    doc.put(DOC_FIELD_TITLE, addRequest.getDoc().getTitle());
    doc.put(DOC_FIELD_CONTENT, addRequest.getDoc().getContent());
    doc.put(DOC_FIELD_DESCRIPTION, addRequest.getDoc().getDescription());
    IndexRequest request = new IndexRequest().index(addRequest.getIndex()).source(doc);
    IndexResponse result = client.index(request, RequestOptions.DEFAULT);

    AddDocResponse response = new AddDocResponse();
    response.setId(result.getId());
    response.setIndex(result.getIndex());
    return response;
  }

  /**
   * 搜索文档
   *
   * @param searchDocRequest 搜索对象
   * @return 文档列表
   * @throws IOException es异常
   */
  @RequestMapping("/search")
  public List<DemoDoc> search(SearchDocRequest searchDocRequest) throws IOException {

    SearchSourceBuilder builder = new SearchSourceBuilder();

    // 1、构造查询条件（只搜索标题和正文内容，不搜索文档描述）
    MultiMatchQueryBuilder qBuilder = new MultiMatchQueryBuilder(searchDocRequest.getKey(), DOC_FIELD_TITLE, DOC_FIELD_CONTENT, DOC_FIELD_DESCRIPTION);
    builder.query(qBuilder);

    // 构建高亮效果
    if (Boolean.TRUE.equals(searchDocRequest.isHighlight())) {
      HighlightBuilder hBuilder = new HighlightBuilder().field(DOC_FIELD_TITLE).field(DOC_FIELD_CONTENT);
      hBuilder.preTags(HIGHLIGHT_PRE_TAG);
      hBuilder.postTags(HIGHLIGHT_POST_TAG);
      builder.highlighter(hBuilder);
    }

    SearchRequest request = new SearchRequest();
    request.indices(searchDocRequest.getIndex());
    request.source(builder);

    SearchResponse esResponse = client.search(request, RequestOptions.DEFAULT);

    List<DemoDoc> list = new ArrayList<>();
    esResponse.getHits().forEach(item -> {
      DemoDoc doc = new DemoDoc();
      Map<String, Object> docObj = item.getSourceAsMap();
      doc.setEsId(item.getId());
      doc.setDescription((String) docObj.get(DOC_FIELD_DESCRIPTION));

      // 处理高亮结果
      if (Boolean.TRUE.equals(searchDocRequest.isHighlight())) {
        item.getHighlightFields().forEach((k, v) -> {
          String text = v.fragments()[0].toString();
          if (DOC_FIELD_TITLE.equals(k)) {
            doc.setTitle(text);
          } else if (DOC_FIELD_CONTENT.equals(k)) {
            doc.setContent(text);
          }
        });
      } else {
        doc.setTitle((String) docObj.get(DOC_FIELD_TITLE));
        doc.setContent((String) docObj.get(DOC_FIELD_CONTENT));
      }

      list.add(doc);
    });
    return list;
  }
}

里面有一些实体类，我们贴出来：

创建索引请求：AddIndexRequest

package com.itf.demo.es;

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

/**
 * @author ye17186
 * @date 2020-05-26
 */
@Data
public class AddIndexRequest implements Serializable {

  private static final long serialVersionUID = -1302118006477723757L;
  /**
   * 索引名
   */
  private String index;

  /**
   * 是否使用ik分词
   */
  private Boolean ik;
}

创建文档请求：AddDocRequest

package com.itf.demo.es;

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

/**
 * @author ye17186
 * @date 2020-05-26
 */
@Data
public class AddDocRequest implements Serializable {

  private static final long serialVersionUID = 962783059289210959L;
  /**
   * es索引
   */
  private String index;

  /**
   * 文档对象
   */
  private DemoDoc doc;

}

文档对象：DemoDoc

package com.itf.demo.es;

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

/**
 * @author ye17186
 * @date 2020-05-27
 */
@Data
public class DemoDoc implements Serializable {

  private static final long serialVersionUID = -4405978680214369148L;

  private String esId;
  /**
   * 文档标题
   */
  private String title;

  /**
   * 文档内容
   */
  private String content;

  /**
   * 文档描述
   */
  private String description;

}

创建文档响应：AddDocResponse

package com.itf.demo.es;

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

/**
 * @author ye17186
 * @date 2020-05-26
 */
@Data
public class AddDocResponse implements Serializable {

  private static final long serialVersionUID = 190213968835835783L;
  /**
   * es索引
   */
  private String index;

  /**
   * 文档ID
   */
  private String id;
}

检索文档请求：SearchDocRequest

package com.itf.demo.es;

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

/**
 * @author ye17186
 * @date 2020-05-26
 */
@Data
public class SearchDocRequest implements Serializable {

  private static final long serialVersionUID = 3713476005328602810L;
  /**
   * es索引
   */
  private String index;

  /**
   * 搜索关键字
   */
  private String key;

  /**
   * 是否高亮
   */
  private boolean highlight;

}

检索文档响应：SearchDocResponse

package com.itf.demo.es;

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

/**
 * @author ye17186
 * @date 2020-05-26
 */
@Data
public class SearchDocResponse implements Serializable {

  private static final long serialVersionUID = -2746189513729052108L;
  /**
   * es索引
   */
  private String index;

  /**
   * 搜索关键字
   */
  private String key;

  /**
   * 匹配到的文档对象
   */
  private List<DemoDoc> docs;

}