ElasticSearch7.8.0+SpringBoot 2.3.12.RELEASE实现高亮搜索+排序+分页

• 引入依赖

<?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>2.3.12.RELEASE</version>
        <relativePath/> <!-- lookup parent from repository -->
    </parent>
    <groupId>com.example</groupId>
    <artifactId>ES-test</artifactId>
    <version>0.0.1-SNAPSHOT</version>
    <name>ES-test</name>
    <description>ES-test</description>
    <properties>
        <java.version>1.8</java.version>
    </properties>
    <dependencies>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter</artifactId>
        </dependency>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-test</artifactId>
            <scope>test</scope>
        </dependency>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-data-elasticsearch</artifactId>
        </dependency>
        <dependency>
            <groupId>org.projectlombok</groupId>
            <artifactId>lombok</artifactId>
        </dependency>
        <dependency>
            <groupId>org.apache.logging.log4j</groupId>
            <artifactId>log4j-core</artifactId>
            <version>2.8.2</version>
        </dependency>
        <!-- junit 单元测试 -->
        <dependency>
            <groupId>junit</groupId>
            <artifactId>junit</artifactId>
            <version>4.12</version>
        </dependency>

    </dependencies>

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

</project>

• 编写方法

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.common.text.Text;
import org.elasticsearch.common.unit.TimeValue;
import org.elasticsearch.index.query.QueryBuilders;
import org.elasticsearch.search.builder.SearchSourceBuilder;
import org.elasticsearch.search.fetch.subphase.highlight.HighlightBuilder;
import org.elasticsearch.search.fetch.subphase.highlight.HighlightField;
import org.elasticsearch.search.sort.SortBuilders;
import org.elasticsearch.search.sort.SortOrder;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.web.bind.annotation.*;
import java.io.IOException;
import java.util.*;
import java.util.concurrent.TimeUnit;


/**
 * 测试ES
 */
@RestController
public class CrudController {


    @Autowired
    private RestHighLevelClient client;

    /**
     * 高亮查询+分页+排序
     * @param keyword 本次搜索的值
     * @param pageNum 分页页码
     * @param pageSize 单页展示条数
     * @return
     */
    @GetMapping("list/{keyword}/{pageNum}/{pageSize}")
    public List<Map<String, Object>> list(@PathVariable("keyword") String keyword,
                                          @PathVariable("pageNum") Integer pageNum,
                                          @PathVariable("pageSize") Integer pageSize) {

        // 从ES查出来并指定title,content字段高亮
        List<Map<String, Object>> list = highLightSearch2("blog", "title", "content", keyword, pageNum, pageSize);
        return list;
    }




    /**
     * 高亮搜索+分页+按照指定字段排序
     *
     * @param indexName 索引名称
     * @param field 需要匹配的字段
     * @param field2 需要匹配的字段
     * @param keyword 匹配的值
     * @param pageNum 分页页码
     * @param pageSize 单页展示条数
     * @return 返回替换原本内容后的数据
     */
    public List<Map<String, Object>> highLightSearch2(String indexName, String field, String field2, String keyword, Integer pageNum, Integer pageSize) {
        List<Map<String, Object>> resList = new ArrayList<>();


        // 1. 创建 SearchRequest并执行索引名称，名称可以指定多个
        SearchRequest searchRequest = new SearchRequest(indexName);

        // 2. 创建 SearchSourceBuilder
        SearchSourceBuilder searchSourceBuilder = new SearchSourceBuilder();

             //避免匹配空字符串
        if("".equals(keyword)){
            //设置需要匹配的字段及匹配的值
            searchSourceBuilder.query(QueryBuilders.matchAllQuery());
        }else{
            //设置需要匹配的字段及匹配的值
            searchSourceBuilder.query(QueryBuilders.multiMatchQuery(keyword, field, field2));
        }
        // 设置分页参数
        searchSourceBuilder.from((pageNum - 1) * pageSize);
        searchSourceBuilder.size(pageSize);
        searchSourceBuilder.timeout(new TimeValue(60, TimeUnit.SECONDS));
        //4.按照score正序排列
        // searchSourceBuilder.sort(SortBuilders.scoreSort().order(SortOrder.ASC));
        //5.按照id倒序排列（score会失效返回NaN）
        searchSourceBuilder.sort(SortBuilders.fieldSort("createTime").order(SortOrder.ASC));

        // 设置高亮规则
        HighlightBuilder highlightBuilder = new HighlightBuilder();
        highlightBuilder.field(field).field(field2);
        //设置高亮代码
        highlightBuilder.preTags("<span style='color:red'>");
        highlightBuilder.postTags("</span>");
        searchSourceBuilder.highlighter(highlightBuilder);

        // 4. 将 SearchSourceBuilder 添加到 SearchRequest
        searchRequest.source(searchSourceBuilder);
        try {
            // 5. 搜索
            SearchResponse response = client.search(searchRequest, RequestOptions.DEFAULT);
            TotalHits totalHits = response.getHits().getTotalHits();
            System.out.println("总记录条数"+totalHits.value);
            // 6. 查询到的文档
            org.elasticsearch.search.SearchHit[] hits = response.getHits().getHits();
            for (org.elasticsearch.search.SearchHit hit : hits) {
                // 获取到全部字段高亮部分
                Map<String, HighlightField> highlightFields = hit.getHighlightFields();

                // 用高亮后的结果取代原来字段
                Map<String, Object> source = hit.getSourceAsMap();

                if (highlightFields.get(field) != null) {
                    // 获取 指定field部分高亮出的片段
                    Text[] fragments = highlightFields.get(field).fragments();
                    // 拼装
                    StringBuilder builder = new StringBuilder();
                    for (Text text : fragments) {
                        builder.append(text);
                    }

                    source.put(field, builder.toString());
                }


                if (highlightFields.get(field2) != null) {
                    // 获取 指定field部分高亮出的片段
                    Text[] fragments2 = highlightFields.get(field2).fragments();
                    // 拼装
                    StringBuilder builder2 = new StringBuilder();
                    for (Text text2 : fragments2) {
                        builder2.append(text2);
                    }

                    source.put(field2, builder2.toString());
                }


                // 将这条记录加入结果集
                resList.add(source);
            }
        } catch (IOException e) {
            System.out.println("===执行搜索失败===");
            e.printStackTrace();
        }
        return resList;
    }
}