SpringBoot Jpa集成Elasticsearch7.6.x, 支持高级动态查询

╰+哭是因爲堅強的太久メ 2022-12-20 12:48 280阅读 0赞

#### 1.环境以及依赖 ####

*  JDK 11.0.8
 *  SpringBoot 2.2.7.RELEASE
 *  spring-data-elasticsearch 4.0.5.RELEASE 对应 ES版本7.6.2
 *  lombok

<dependency>
    	<groupId>org.springframework.data</groupId>
    	<artifactId>spring-data-elasticsearch</artifactId>
    	<version>4.0.5.RELEASE</version>
    </dependency>

#### 2.背景介绍 ####

原来的mysql库里有张商品表, 对商品名进行模糊搜索, 一开始走mysql时间还可以接受. 随着数据累积, 需要走ES搜索优化接口响应速度.

#### 3.引入并集成Elasticsearch ####

##### 3.1引入ES依赖 #####

其实这里可以引入ES的SpringBoot starter. 我这里是因为已经先有了7.6版本的ES环境,导致和项目需要的版本不一致, 才自己另外引入了其他版本的依赖

##### 3.2 yml文件配置 #####

spring:  
      elasticsearch:
        rest:
          uris: http://localhost:9200

##### 3.3实体类的改造 #####

原本已经存在了一个ItemInfoAnalysed.java的实体类. 我选择了新建一个ESItemInfoAnalysed.java类,然后在类上加`@Document`注解声明这个类是映射到ES中的一个doc  
原本的ItemInfoAnalysed类中createTime是**LocalDateTime**类型的, 但是保存到ES中会自动转换成时间戳, 所以我们ESItemInfoAnalysed类中需要把createTime声明成**Long**类型.

@Data
    @NoArgsConstructor
    @Document(indexName = "iteminfoanalysed", refreshInterval = "0")
    public class EsItemInfoAnalysed {
        
        @Id
        private Long id;
        private Long createTime;
    }

实体类中涉及的注解有`@Document`, `@Id`, `@Field`, 具体的解释可以参见[这篇博客的1.2章: 创建文档实体对象][1.2_]. 这篇博客写的还是很好的, 就是时间有点久远,里面用到的方法现在都已经被官方废弃了.

#### 4.动态查询 ####

##### 4.1构造查询语句 #####

为了在jpa中实现复杂的动态查询, 我们借助`NativeSearchQuery`构造查询条件. 创建一个EsItemInfoAnalysedCmd类来接收前端的查询参数并在类里面构造查询语句.

@Data
    @NoArgsConstructor
    public class EsItemInfoAnalysedCmd {
         
        private Integer type;
        private Integer dateFrom;
        private Integer dateTo;
        private List<String> sourceType;
        private Integer salesVolumeFrom;
        private Integer salesVolumeTo;
        private String title;
    
        public EsItemInfoAnalysedCmd(String title, List<String> sourceType, Integer salesVolumeFrom,
                                     Integer salesVolumeTo, Integer dateFrom, Integer dateTo) {
        
            this.title = title;
            this.sourceType = sourceType;
            this.salesVolumeFrom = salesVolumeFrom;
            this.salesVolumeTo = salesVolumeTo;
            this.type = type;
            this.dateFrom = dateFrom;
            this.dateTo = dateTo;
        }
    
        /**
         * JPA的复杂查询
         *
         * @return /
         */
        public Query buildQuery(Pageable pageable) {
        
            BoolQueryBuilder builder = QueryBuilders.boolQuery();
            if (type != null) {
        
                //term用来精确查询数字（numbers）、布尔值（Booleans）、日期（dates)
                builder.must(QueryBuilders.termQuery("type", type));
            }
            //范围查询, between
            if (dateFrom != null && dateTo != null) {
        
                builder.must(QueryBuilders.rangeQuery("date").from(dateFrom).to(dateTo));
            }
            if (sourceType != null && sourceType.size() > 0) {
        
                //terms用来查询文本或者多个值
                builder.must(QueryBuilders.termsQuery("sourceType", toStringArray(sourceType)));
            }
            //销量xx以上, >=
            if (salesVolumeFrom != null && salesVolumeTo == null) {
        
                builder.must(QueryBuilders.rangeQuery("salesVolume").gte(salesVolumeFrom));
            }
            //模糊查询, 只要是包换title的都返回
            if (!StringUtils.isEmpty(title)) {
        
                builder.must(QueryBuilders.matchPhraseQuery("title", title));
            }
            //构建查询语句
            return new NativeSearchQueryBuilder().withQuery(builder)
                    .withPageable(pageable) //SpringBoot提供的分页参数
                    .build();
        }
    
        private String[] toStringArray(List<String> sourceType) {
        
            String[] res = new String[sourceType.size()];
            for (int i = 0; i < sourceType.size(); i++) {
        
                res[i] = sourceType.get(i);
            }
            return res;
        }
    }

##### 4.2Controller #####

import org.springframework.data.domain.Pageable;
    import org.springframework.http.HttpStatus;
    import org.springframework.http.ResponseEntity;
    
    @GetMapping("/es")
    public ResponseEntity<Page<EsItemInfoAnalysed>> esList(@RequestParam(required = false) String title,
    									@RequestParam(required = false) List<String> sourceType,
    									@RequestParam(required = false) Integer type,
    									@RequestParam(required = false) Integer salesVolumeFrom,
    									@RequestParam(required = false) Integer salesVolumeTo,
    									@RequestParam(required = false) Integer dateFrom,
    									@RequestParam(required = false) Integer dateTo, Pageable pageable) {
        
    
    	EsItemInfoAnalysedCmd cmd = new EsItemInfoAnalysedCmd(title, sourceType, type, salesVolumeFrom, salesVolumeTo, dateFrom, dateTo);
    	Page<EsItemInfoAnalysed> page = itemInfoAnalysedService.esList(cmd, pageable);
    	return new ResponseEntity<>(page, HttpStatus.OK);
    }

##### 4.3ServiceImp #####

官方提供了一个ElasticsearchRestTemplate来实现与es的交互. 传统的jpa模式是新建一个接口实现Repository接口, 不过ElasticsearchRepository的方法几乎全部被废弃, 因此我这里使用了官方推荐的方法.

import org.springframework.data.elasticsearch.core.ElasticsearchRestTemplate;
    
    @Service
    public class ItemInfoAnalysedServiceImpl implements ItemInfoAnalysedService {
        
        private final ElasticsearchRestTemplate elasticsearchRestTemplate;
    
        public ItemInfoAnalysedServiceImpl(ElasticsearchRestTemplate elasticsearchRestTemplate) {
        
            this.elasticsearchRestTemplate = elasticsearchRestTemplate;
        }
    	
    	@Override
        public Page<EsItemInfoAnalysed> esList(EsItemInfoAnalysedCmd cmd, Pageable pageable) {
        
            SearchHits<EsItemInfoAnalysed> hits = elasticsearchRestTemplate.search(cmd.buildQuery(pageable), EsItemInfoAnalysed.class);
            return EsItemInfoAnalysed.build(hits, pageable);
        }
    }

##### 4.4 EsItemInfoAnalysed.build() #####

public static Page<EsItemInfoAnalysed> build(SearchHits<EsItemInfoAnalysed> hits, Pageable pageable) {
        
    	List<EsItemInfoAnalysed> content = new ArrayList<>(hits.getSearchHits().size());
    	for (SearchHit<EsItemInfoAnalysed> hit : hits) {
        
    		content.add(hit.getContent());
    	}
    	return new PageImpl<>(content, pageable, hits.getTotalHits());
    }

[1.2_]: https://blog.csdn.net/Topdandan/article/details/81436141