spring boot 3使用 elasticsearch 提供搜索建议

业务场景

用户输入内容，快速返回建议，示例效果如下

技术选型

• spring boot 3
• elasticsearch server 7.17.4
• spring data elasticsearch 5.0.1
• elasticsearch-java-api 8.5.3

pom.xml

  <dependency>
      <groupId>org.springframework.boot</groupId>
      <artifactId>spring-boot-starter-data-elasticsearch</artifactId>
  </dependency>
  <dependency>
     <groupId>org.elasticsearch</groupId>
     <artifactId>elasticsearch</artifactId>
     <version>8.5.3</version>
 </dependency>
        

yml

spring:
  elasticsearch:
    uris: http://127.0.0.1:9200
  data:
    elasticsearch:
      repositories:
        enabled: true

实体类

为了启动时候自己创建相关的index，以及存储搜索内容

import org.springframework.data.annotation.Id;
import org.springframework.data.elasticsearch.annotations.CompletionField;
import org.springframework.data.elasticsearch.annotations.Document;
import org.springframework.data.elasticsearch.annotations.Field;
import org.springframework.data.elasticsearch.annotations.FieldType;
import org.springframework.data.elasticsearch.core.suggest.Completion;

/**
 * 业务搜索建议
 * @author chunyang.leng
 * @date 2023-08-21 14:24
 */
@Document(indexName = "biz_suggest")
public class BizSuggestDocument {

    @Id
    private Long id;

    /**
     * 标题，可以用于纠错，不参与搜索建议
     */
    @Field(type = FieldType.Text, analyzer = "ik_max_word")
    private String name;

    /**
     * 自动补全标题，搜索建议使用的对象
     */
    @CompletionField(analyzer = "ik_max_word", searchAnalyzer = "ik_smart")
    private Completion completionName;

    public Long getId() {
        return id;
    }

    public void setId(Long id) {
        this.id = id;
    }

    public String getName() {
        return name;
    }

    public void setName(String name) {
        this.name = name;
    }

    public Completion getCompletionName() {
        return completionName;
    }

    public void setCompletionName(Completion completionName) {
        this.completionName = completionName;
    }
}

搜索结果对象

/**
 * 搜索建议返回对象
 * @author chunyang.leng
 * @date 2023-08-21 19:02
 */
public class SuggestVO {
    /**
     * 数据id
     */
    private Long id;

    /**
     * 内容
     */
    private String text;

    public Long getId() {
        return id;
    }

    public void setId(Long id) {
        this.id = id;
    }

    public String getText() {
        return text;
    }

    public void setText(String text) {
        this.text = text;
    }
}

搜索业务层

• 数据导入时候，因为有数据格式要求，必须使用实体类进行写入

import co.elastic.clients.elasticsearch.ElasticsearchClient;
import co.elastic.clients.elasticsearch.core.SearchRequest;
import co.elastic.clients.elasticsearch.core.SearchResponse;
import co.elastic.clients.elasticsearch.core.search.CompletionSuggester;
import co.elastic.clients.elasticsearch.core.search.Suggester;
import co.elastic.clients.elasticsearch.core.search.Suggestion;
import co.elastic.clients.elasticsearch.core.search.TermSuggester;
import java.io.IOException;
import java.util.List;
import java.util.Map;
import java.util.stream.Collectors;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Component;

/**
 * @author chunyang.leng
 * @date 2023-08-18 18:29
 */
@Component
public class SuggestionServiceImpl implements SuggestionService {
    /**
     * 搜索建议 key
     */
    private static final String SUGGEST_TAG = "suggest_query";

    /**
     * 纠错key
     */
    private static final String TERM_TAG = "suggest_team";
    @Autowired
    private ElasticsearchClient elasticsearchClient;

    /**
     * 根据 关键词，返回搜索建议
     *
     * @param match 搜索关键词
     * @return 搜索建议，10条
     */
    @Override
    public List<SuggestVO> suggest(String match) throws IOException {
        SearchRequest completionSuggestSearchRequest = new SearchRequest
            .Builder()
            .suggest(
                new Suggester
                    .Builder()
                    .suggesters(SUGGEST_TAG, builder -> builder.prefix(match)
                        .completion(new CompletionSuggester
                            .Builder()
                            .field("completionName")
                            .size(10)
                            .build()
                        )
                    )
                    .build())
            .build();

        SearchResponse<BizSuggestDocument> completionSuggestSearch = elasticsearchClient.search(completionSuggestSearchRequest, BizSuggestDocument.class);

        Map<String, List<Suggestion<BizSuggestDocument>>> suggest = completionSuggestSearch.suggest();

        List<Suggestion<BizSuggestDocument>> suggestions = suggest.get(SUGGEST_TAG);

        return suggestions
            .parallelStream()
            .flatMap(x -> x.completion()
                .options()
                .stream()
                .map(o -> {
                      // 原始数据对象，如果有需要，可以对其进行操作
                    BizSuggestDocument source = o.source();
                    
                   
                    String text = o.text();
                    String idValue = o.id();
                    Long id = Long.valueOf(idValue);
                    SuggestVO vo = new SuggestVO();
                    vo.setId(id);
                    vo.setText(text);
                    return vo;
                }))
            .collect(Collectors.toList());
    }
}

导入数据

import org.junit.jupiter.api.Test;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.boot.test.context.SpringBootTest;
import org.springframework.data.elasticsearch.client.elc.ElasticsearchTemplate;
import org.springframework.data.elasticsearch.core.suggest.Completion;

/**
 * @author chunyang.leng
 * @date 2023-08-21 18:09
 */
@SpringBootTest
public class EsTest {

    @Autowired
    private ElasticsearchTemplate elasticsearchTemplate;

    @Test
    public void test() {
        BizSuggestDocument document = new BizSuggestDocument();
        document.setId(1L);
        document.setName("飞翔的世界");

        String[] s = "你的世界1.0,我的世界2.0".split(",");
        Completion completion = new Completion(s);
        completion.setWeight(10);
        document.setCompletionName(completion);
        elasticsearchTemplate.save(document);


        BizSuggestDocument document2 = new BizSuggestDocument();
        document2.setId(2L);
        document2.setName("路人甲乙丙");

        String[] s2 = "你的滑板鞋1.0,我的滑板鞋2.0".split(",");
        Completion completion1 = new Completion(s2);
        completion1.setWeight(5);
        document2.setCompletionName(completion1);
        elasticsearchTemplate.save(document2);
    }
}

POSTMAN 测试结果如下