SpringBoot集成elasticsearch使用图文详解

<!--springboot帮我们自动集成了es，所以只需要引入下面这一个依赖即可-->
<dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-data-elasticsearch</artifactId>
        </dependency>

@Configuration
public class EsConfig {

    @Bean
    public RestHighLevelClient highLevelClient(){
        final ClientConfiguration clientConfiguration = ClientConfiguration.builder()
                .connectedTo("localhost:9200")
                .build();
        return RestClients.create(clientConfiguration).rest();
    }
}

@Data
@Document(indexName = "book")
//es默认会自动创建索引，你可以把document理解为数据库中的行，index理解为数据库中的表，以前在index和document之间还有个type对应数据库中的表概念。后面es7之后将type去掉了，所以这里就简单把index当作一个表的概念去理解
public class Book {
    @Id
    @Field(type = FieldType.Long)//type表示存到es当中的数据类型
    private Long id;
    @Field(type = FieldType.Text,analyzer = "ik-max-word")
    private String bookName;//analyzer 表示选择分词器
    @Field(type = FieldType.Text,analyzer = "ik-max-word")
    private String bookDesc;
    @Field(type = FieldType.Text)
    private String type;
    @Field(type = FieldType.Integer)
    private Integer status;
    @Field(analyzer = "ik-max-word")
    private String author;
    @Field(type = FieldType.Text)
    private String tag;
    @Field(type = FieldType.Date,format = DateFormat.basic_date_time)
    private LocalDateTime createTime;
    @Field(type = FieldType.Text)
    private String createBy;
    @Field(type = FieldType.Date,format = DateFormat.basic_date_time)
    private LocalDateTime updateTime;

}

//
// Source code recreated from a .class file by IntelliJ IDEA
// (powered by FernFlower decompiler)
//

package org.springframework.data.elasticsearch.repository;

import org.elasticsearch.index.query.QueryBuilder;
import org.springframework.data.domain.Page;
import org.springframework.data.domain.Pageable;
import org.springframework.data.elasticsearch.core.query.Query;
import org.springframework.data.repository.NoRepositoryBean;
import org.springframework.data.repository.PagingAndSortingRepository;
import org.springframework.lang.Nullable;

@NoRepositoryBean
public interface ElasticsearchRepository<T, ID> extends PagingAndSortingRepository<T, ID> {
    /** @deprecated */
    @Deprecated
    default <S extends T> S index(S entity) {
        return this.save(entity);
    }

    /** @deprecated */
    @Deprecated
    <S extends T> S indexWithoutRefresh(S entity);

    /** @deprecated */
    @Deprecated
    Iterable<T> search(QueryBuilder query);

    /** @deprecated */
    @Deprecated
    Page<T> search(QueryBuilder query, Pageable pageable);

    /** @deprecated */
    Page<T> search(Query searchQuery);

    Page<T> searchSimilar(T entity, @Nullable String[] fields, Pageable pageable);

    /** @deprecated */
    @Deprecated
    void refresh();
}

//这里定义了两个查询条件：书名和作者，直接将搜索值传递给定义好的方法就行
List<Book> booksByBookNameAndAuthor = esBookRepository.findBooksByBookNameOrAuthor(nameAndAuthor,nameAndAuthor);

 /**
     * 书名、作者搜索
     */
    @RequestMapping(method = RequestMethod.GET, value = {"/book/search" })
    public RestResponse<List<Book>> search(@RequestParam String nameAndAuthor){
        BoolQueryBuilder queryBuilder = new BoolQueryBuilder();

//匹配两个高亮字段：书名、作者
        queryBuilder.should(QueryBuilders.matchQuery("bookName",nameAndAuthor))
                .should(QueryBuilders.matchQuery("author",nameAndAuthor));
                //设置查询高亮样式preTags、postTags
                //高亮查询其实就是给相应需要高亮显示的字段加个自定义样式
        NativeSearchQuery query = new NativeSearchQueryBuilder()
                .withQuery(queryBuilder)
                        .withHighlightFields(new HighlightBuilder.Field("bookName")
                        ,new HighlightBuilder.Field("author"))
                                .withHighlightBuilder(new HighlightBuilder().preTags("<span style='color:red'>").postTags("</span>"))
                                        .build();
        SearchHits<Book> search = elasticsearchRestTemplate.search(query, Book.class);
        List<SearchHit<Book>> searchHits = search.getSearchHits();
        //查询返回结果，将高亮字段重新赋值给相应book对象，以便返回前端展示
        List<Book> collect = searchHits.stream().map(
                bookSearchHit -> {
                    Book content = bookSearchHit.getContent();
                    List<String> bookName = bookSearchHit.getHighlightField("bookName");
                    List<String> author = bookSearchHit.getHighlightField("author");
                    if (!CollectionUtils.isEmpty(bookName)){
                        content.setBookName(bookName.get(0));
                    }
                    if (!CollectionUtils.isEmpty(author)){
                        content.setAuthor(author.get(0));
                    }
                    return content;
                }
        ).collect(Collectors.toList());
        return RestResponse.success(collect);
    }