一、前言
我們?cè)谑褂盟阉鞴δ艿臅r(shí)候，有時(shí)，為了使搜索的結(jié)果更多更廣，比如搜索字符串“領(lǐng)導(dǎo)力”，希望有這些組合的結(jié)果（領(lǐng)導(dǎo)力、領(lǐng)導(dǎo)、領(lǐng)、導(dǎo)、力）都要能夠全部展示出來。
這里我們引入ElasticSearch結(jié)合分詞插件，來實(shí)現(xiàn)這樣的搜索功能。
二、搜索功能的需求
比如：一款app需要對(duì)“課程”進(jìn)行關(guān)鍵字搜索。
首先：課程包含的信息有：標(biāo)題、子標(biāo)題、講師、簡介、所屬標(biāo)簽、封面圖片、講數(shù)等等。
搜索的需求為：輸入關(guān)鍵字，要能分詞匹配課程的這些信息：標(biāo)題、子標(biāo)題、講師、所屬標(biāo)簽。
搜索需求：搜索結(jié)果的原型圖如下圖所示：![[Spring Boot]12 ElasticSearch實(shí)現(xiàn)分詞搜索功能](https://imgs.yssmx.com/Uploads/2023/05/436457-1.png)
紅色高亮為搜索結(jié)果，覆蓋了標(biāo)題、子標(biāo)題、所屬標(biāo)簽、講師名稱，并能進(jìn)行分詞搜索且關(guān)鍵字高亮。
三、需求開發(fā)
1、服務(wù)器安裝ElasticSearch和IK分詞器
參考鏈接: [Linux安裝軟件詳解系列]05 安裝ElasticSearch和IK分詞器
2、需求開發(fā)
1）pom.xml引入jar包：
<!--elasticsearch-->
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-data-elasticsearch</artifactId>
</dependency>
2）yml增加配置
// 安裝ElasticSearch時(shí)對(duì)應(yīng)的信息
elasticsearch:
rest:
uris: http://ip:9200
username: test
password: 123456
3）配置類ElasticsearchConfig
ElasticsearchConfig：
package com.test.api.config;
import org.elasticsearch.client.RestHighLevelClient;
import org.springframework.beans.factory.annotation.Value;
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;
import org.springframework.data.elasticsearch.repository.config.EnableElasticsearchRepositories;
/**
* es 配置
*
* @author /
*/
@EnableElasticsearchRepositories(basePackages = {"com.test.bi.*.repository"})
@Configuration
public class ElasticsearchConfig {
@Value("${spring.elasticsearch.rest.uris}")
private String hostAndPort;
@Value("${spring.elasticsearch.rest.username}")
private String username;
@Value("${spring.elasticsearch.rest.password}")
private String password;
@Bean
public RestHighLevelClient elasticsearchClient() {
ClientConfiguration clientConfiguration = ClientConfiguration.builder()
.connectedTo(hostAndPort)
.withBasicAuth(username, password)
.build();
return RestClients.create(clientConfiguration).rest();
}
}
4）工具類ElasticsearchUtil
ElasticsearchUtil：
package com.test.common.util;
import cn.hutool.core.collection.CollectionUtil;
import cn.hutool.json.JSONUtil;
import com.github.pagehelper.PageInfo;
import lombok.AllArgsConstructor;
import lombok.Data;
import lombok.SneakyThrows;
import lombok.extern.slf4j.Slf4j;
import org.elasticsearch.action.bulk.BulkRequest;
import org.elasticsearch.action.bulk.BulkResponse;
import org.elasticsearch.action.delete.DeleteRequest;
import org.elasticsearch.action.search.SearchRequest;
import org.elasticsearch.action.search.SearchResponse;
import org.elasticsearch.action.search.SearchScrollRequest;
import org.elasticsearch.action.support.WriteRequest;
import org.elasticsearch.client.RequestOptions;
import org.elasticsearch.client.RestHighLevelClient;
import org.elasticsearch.common.text.Text;
import org.elasticsearch.common.unit.TimeValue;
import org.elasticsearch.search.SearchHit;
import org.elasticsearch.search.builder.SearchSourceBuilder;
import org.elasticsearch.search.fetch.subphase.highlight.HighlightBuilder;
import org.elasticsearch.search.fetch.subphase.highlight.HighlightField;
import org.springframework.stereotype.Component;
import org.springframework.util.CollectionUtils;
import org.springframework.util.ReflectionUtils;
import javax.annotation.Resource;
import java.io.IOException;
import java.lang.reflect.Field;
import java.lang.reflect.Method;
import java.util.ArrayList;
import java.util.Collection;
import java.util.List;
import java.util.Map;
/**
* es 工具類
*
* @author /
*/
@Slf4j
@Component
public class ElasticsearchUtil {
@Resource
private RestHighLevelClient restHighLevelClient;
/**
* 普通查詢
*
* @param index 索引名稱
* @param searchSourceBuilder 查詢條件構(gòu)建
* @param resultClass 類
* @param currentPage 當(dāng)前頁 分頁的頁碼，不是es 的
* @param size 每頁顯示數(shù)據(jù)
*/
public <T> PageInfo<T> page(String index, SearchSourceBuilder searchSourceBuilder, Class<T> resultClass,
int currentPage, int size, List<String> highFields) {
SearchRequest request = new SearchRequest(index);
// 高亮字段設(shè)置
if (CollectionUtil.isNotEmpty(highFields)) {
buildHighLight(searchSourceBuilder, highFields);
}
// 分頁
int num = (currentPage - 1) * size;
searchSourceBuilder.from(num)
.size(size);
request.source(searchSourceBuilder);
SearchResponse response = null;
try {
response = restHighLevelClient.search(request, RequestOptions.DEFAULT);
} catch (IOException e) {
e.printStackTrace();
}
assert response != null;
return analysisResponse(response, resultClass, currentPage, size, highFields);
}
/**
* 解析es 查詢結(jié)果
*
* @param response 返回
* @param resultClass 轉(zhuǎn)換成對(duì)象類
*/
private <T> PageInfo<T> analysisResponse(SearchResponse response, Class<T> resultClass, int currentPage, int size, List<String> highFields) {
SearchHit[] searchHits = response.getHits().getHits();
List<T> retList = new ArrayList<>(searchHits.length);
for (SearchHit searchHit : searchHits) {
String strJson = searchHit.getSourceAsString();
T t = JSONUtil.toBean(strJson, resultClass);
try {
setId(resultClass, t, String.valueOf(searchHit.getId()));
} catch (Exception e) {
log.info("es 查詢數(shù)據(jù)設(shè)置主鍵id值異常", e);
}
// 高亮字段設(shè)置后，組織結(jié)果，es 結(jié)果建議與java 對(duì)象 名稱一直，基本要求
if (!CollectionUtils.isEmpty(highFields)) {
Map<String, HighlightField> highlightFieldMap = searchHit.getHighlightFields();
HighlightField highlightField;
for (String field : highFields) {
highlightField = highlightFieldMap.get(field);
if (highlightField != null) {
// 獲取指定字段的高亮片段
Text[] fragments = highlightField.getFragments();
// 將這些高亮片段拼接成一個(gè)完整的高亮字段
StringBuilder builder = new StringBuilder();
for (Text text : fragments) {
builder.append(text);
}
// 設(shè)置到實(shí)體類中
setValue(resultClass, t, builder.toString(), field);
}
}
}
retList.add(t);
}
long totalNum = response.getHits().getTotalHits();
PageInfo<T> pageVo = new PageInfo<>();
pageVo.setPageNum(currentPage);
pageVo.setPageSize(size);
pageVo.setTotal(totalNum);
pageVo.setList(retList);
return pageVo;
}
/**
* 對(duì)象id 為空時(shí)，給id 賦值
*
* @param resultClass 類
* @param t 對(duì)象
* @param id 主鍵id 的值
*/
@SneakyThrows
private <T> void setId(Class<T> resultClass, T t, Object id) {
Field field = ReflectionUtils.findField(resultClass, "id");
if (null != field) {
field.setAccessible(true);
Object object = ReflectionUtils.getField(field, t);
if (object == null) {
Method method = resultClass.getMethod("setId", String.class);
ReflectionUtils.invokeMethod(method, t, id);
}
}
}
/**
* 指定字段賦值
*
* @param resultClass 類
* @param t 對(duì)象
* @param fieldValue 字段名
* @param fieldName 字段值
*/
@SneakyThrows
private <T> void setValue(Class<T> resultClass, T t, Object fieldValue, String fieldName) {
Field field = ReflectionUtils.findField(resultClass, fieldName);
if (null != field) {
field.setAccessible(true);
String methodName = "set".concat(captureName(fieldName));
Method method = resultClass.getMethod(methodName, String.class);
ReflectionUtils.invokeMethod(method, t, fieldValue);
}
}
/**
* 進(jìn)行字母的ascii編碼前移，效率要高于截取字符串進(jìn)行轉(zhuǎn)換的操作
*
* @param str /
*/
private String captureName(String str) {
char[] cs = str.toCharArray();
cs[0] -= 32;
return String.valueOf(cs);
}
/**
* 設(shè)置高亮
*
* @param searchSourceBuilder /
* @param fields 高亮字段
*/
private void buildHighLight(SearchSourceBuilder searchSourceBuilder, List<String> fields) {
// 設(shè)置高亮
HighlightBuilder highlightBuilder = new HighlightBuilder();
fields.forEach(highlightBuilder::field);
highlightBuilder.preTags("<em>");
highlightBuilder.postTags("</em>");
// 給請(qǐng)求設(shè)置高亮
searchSourceBuilder.highlighter(highlightBuilder);
}
/**
* es Scroll 深分頁 定義bean
*/
@AllArgsConstructor
@Data
public class ScrollPageBean<T> {
private String scrollId;
private PageInfo<T> scrollPage;
}
}
5）返回的數(shù)據(jù)BO封裝
package com.test.bi.bo.course;
import io.swagger.annotations.ApiModelProperty;
import lombok.Data;
import org.springframework.data.annotation.Id;
import org.springframework.data.elasticsearch.annotations.Document;
import org.springframework.data.elasticsearch.annotations.Field;
import org.springframework.data.elasticsearch.annotations.FieldType;
import java.io.Serializable;
/**
* 課程-搜索
*
* @author /
*/
@Document(indexName = "course_es", type = "_doc", replicas = 0)
@Data
public class CourseEsDTO implements Serializable {
@ApiModelProperty(value = "課程編號(hào)")
@Id
private String id;
@ApiModelProperty(value = "標(biāo)題")
@Field(type = FieldType.Text, analyzer = "ik_max_word")
private String name;
@ApiModelProperty(value = "講師名稱")
@Field(type = FieldType.Text, analyzer = "ik_max_word")
private String teacherName;
@ApiModelProperty(value = "子標(biāo)題")
@Field(type = FieldType.Text, analyzer = "ik_max_word")
private String subtitle;
@ApiModelProperty(value = "所屬標(biāo)簽名稱列表")
@Field(type = FieldType.Text, analyzer = "ik_max_word")
private String labelName;
@ApiModelProperty(value = "封面圖片")
@Field(type = FieldType.Text)
private String pic;
@ApiModelProperty(value = "講數(shù)")
@Field(type = FieldType.Integer)
private Integer count;
}
6）保存數(shù)據(jù)至ElasticSearch
保存數(shù)據(jù)到ElasticSearch中，通常有兩種方式：一種是通過ElasticsearchRepository 接口，另一種是通過ElasticsearchTemplate接口，我們使用ElasticsearchRepository接口來實(shí)現(xiàn)。
實(shí)現(xiàn)接口：CourseEsRepository，可以放在mapper里面。
package com.test.bi.mapper;
import com.test.bi.bo.course.CourseEsDTO;
import org.springframework.data.elasticsearch.repository.ElasticsearchRepository;
import org.springframework.stereotype.Repository;
/**
* 課程-搜索
*
* @author /
*/
@Repository
public interface CourseEsRepository extends ElasticsearchRepository<CourseEsDTO, String> {
}
保存數(shù)據(jù)：文章來源：http://www.zghlxwxcb.cn/news/detail-436457.html
@Resource
private CourseEsRepository courseEsRepository;
@Override
public void saveCourseEs() {
try {
courseEsRepository.deleteAll();
// 從庫中取數(shù)據(jù)
List<CourseEsDTO> list = courseMapper.getCourseEsList();
if (IterUtil.isNotEmpty(list)) {
courseEsRepository.saveAll(list);
}
} catch (Exception e) {
log.error("es error:{}", e.getMessage());
}
}
7）根據(jù)關(guān)鍵字搜索，分頁返回?cái)?shù)據(jù)
@Override
public PageInfo<CourseEsDTO> getCourseEs(String keywords, Integer pageNum, Integer pageSize) {
// 使用best_fields模式, 對(duì)多個(gè)字段進(jìn)行查詢
SearchSourceBuilder searchSourceBuilder = new SearchSourceBuilder();
String[] queryFields = {"teacherName", "subtitle", "labelName"
};
QueryBuilder queryBuilder = QueryBuilders.multiMatchQuery(keywords, queryFields)
.field("name", 2F)
.tieBreaker(0.3F);
searchSourceBuilder.query(queryBuilder);
// 高亮
List<String> highFields = ListUtil.toList(queryFields);
highFields.add("name");
// 分頁返回?cái)?shù)據(jù)
return elasticsearchUtil.page("course_es", searchSourceBuilder, CourseEsDTO.class, pageNum,
pageSize, highFields);
}
8）總結(jié)
總結(jié)一下，就是通過一個(gè)小的需求例子，很好地實(shí)現(xiàn)了分詞搜索，并且要能夠高亮顯示關(guān)鍵字。
具體的ElasticSearch和對(duì)應(yīng)iK分詞的代碼功能，我就不一一展開了，可以去官方查看，這里只是演示一下實(shí)現(xiàn)搜索功能的簡單過程，希望對(duì)大家有所幫助。文章來源地址http://www.zghlxwxcb.cn/news/detail-436457.html
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