对于ElasticSearch比较陌生的小伙伴可以先看看ElasticSearch的概述ElasticSearch安装、启动、操作及概念简介
好的开始啦~
org.springframework.boot spring-boot-starter-data-elasticsearch
新版本配置方式(推荐使用)
新的配置方式使用的是 High Level REST Client 的方式来替代之前的 Transport Client 方式,使用的是 HTTP 请求,和 Kibana 一样使用的是 Elasticsearch 的 9200 端口。
这种配置方案中,你使用的不是配置文件,而是自定义配置类:
/** * 你也可以不继承 AbstractElasticsearchConfiguration 类,而将 ESConfig 写成一般的配置类的型式。 * 不过继承 AbstractElasticsearchConfiguration 好处在于,它已经帮我们配置好了 elasticsearchTemplate 直接使用。 */ @Configuration public class ESConfig extends AbstractElasticsearchConfiguration { @Override public RestHighLevelClient elasticsearchClient() { ClientConfiguration clientConfiguration = ClientConfiguration.builder() .connectedTo("localhost:9200") .build(); return RestClients.create(clientConfiguration).rest(); } }
Elasticsearch 中的 PO 类:
@Document(indexName = "books",shards = 1,replicas = 0) @Data @AllArgsConstructor @NoArgsConstructor public class ESBook { @Id @Field(type = FieldType.Keyword) private String id; @Field(type = FieldType.Text) private String title; @Field(type = FieldType.Keyword) private String language; @Field(type = FieldType.Keyword) private String author; @Field(type = FieldType.Float) private Float price; @Field(type = FieldType.Text) private String description; }
@Repository //看实体类Id索引是什么类型 我这里是String public interface ESBookRepstitory extends ElasticsearchRepository{ }
我们自定义的 CustomerRepository 接口,从它的祖先们那里继承了大量的现成的方法,除此之外,它还可以按 spring data 的规则定义特定的方法。
// 创建索引 @Test public void indexList() { System.out.println("创建索引"); } // 删除索引 @Test public void indexList() { restTemplate.indexOps(IndexCoordinates.of("books")).delete(); System.out.println("删除索引"); }
@Autowired private ESBookRepstitory bookByESRepstitory; @Test public void indexList() { Listlists = new ArrayList<>(); lists.add(new ESBook("1", "Java 程序设计", "汉语", "盖伦", 18.88F, "哈哈嗨")); lists.add(new ESBook("2", "Python程序设计", "英语", "赵信", 66.88F, "陷阵之至有死无生")); lists.add(new ESBook("3", "PHP 程序设计", "俄语", "宝石", 88.88F, "我曾踏足山巅,也曾跌入低谷")); bookByESRepstitory.saveAll(lists); }
id重复的话 会覆盖之前的~~~
修改和新增是同一个接口,区分的依据就是id,这一点跟我们在页面发起PUT请求是类似的。
ESBook ESBook = new ESBook("3", "宝石 程序设计", "俄语", "宝石", 88.88F, "我曾踏足山巅,也曾跌入低谷"); bookByESRepstitory.save(ESBook); //由于上面的id = 3 已经存在,故再次save 就是修改
@Test public void test2(){ bookByESRepstitory.deleteById("1"); bookByESRepstitory.deleteAll(); }
@Test public void testQuery(){ OptionaloptionalById = this.bookByESRepstitory.findById("1"); System.out.println(optionalById.get()); } @Test public void testFind(){ // 查询全部,并按照价格降序排序 //写法一: Iterable items = this.bookByESRepstitory.findAll(Sort.by(Sort.Direction.DESC, "price")); //写法二: Iterable items1 = this.bookByESRepstitory.findAll(Sort.by(Sort.Order.desc("price"))); }
Spring Data 自带的分页方案:
@Test public void testByPage(){ Sort sort = Sort.by(Sort.Direction.DESC,"id"); //分页 PageRequest pageRequest = PageRequest.of(0, 2, sort); Pageall = bookByESRepstitory.findAll(pageRequest); for (BookByES bookByES : all) { System.out.println(bookByES); } }
Spring Data 的另一个强大功能,是根据方法名称自动实现功能。
比如:你的方法名叫做:findByTitle,那么它就知道你是根据title查询,然后自动帮你完成,无需写实现类。
当然,方法名称要符合一定的约定
Keyword | Sample | Elasticsearch Query String |
---|---|---|
And | findByNameAndPrice | {"bool" : {"must" : [ {"field" : {"name" : "?"}}, {"field" : {"price" : "?"}} ]}} |
Or | findByNameOrPrice | {"bool" : {"should" : [ {"field" : {"name" : "?"}}, {"field" : {"price" : "?"}} ]}} |
Is | findByName | {"bool" : {"must" : {"field" : {"name" : "?"}}}} |
Not | findByNameNot | {"bool" : {"must_not" : {"field" : {"name" : "?"}}}} |
Between | findByPriceBetween | {"bool" : {"must" : {"range" : {"price" : {"from" : ?,"to" : ?,"include_lower" : true,"include_upper" : true}}}}} |
LessThanEqual | findByPriceLessThan | {"bool" : {"must" : {"range" : {"price" : {"from" : null,"to" : ?,"include_lower" : true,"include_upper" : true}}}}} |
GreaterThanEqual | findByPriceGreaterThan | {"bool" : {"must" : {"range" : {"price" : {"from" : ?,"to" : null,"include_lower" : true,"include_upper" : true}}}}} |
Before | findByPriceBefore | {"bool" : {"must" : {"range" : {"price" : {"from" : null,"to" : ?,"include_lower" : true,"include_upper" : true}}}}} |
After | findByPriceAfter | {"bool" : {"must" : {"range" : {"price" : {"from" : ?,"to" : null,"include_lower" : true,"include_upper" : true}}}}} |
Like | findByNameLike | {"bool" : {"must" : {"field" : {"name" : {"query" : "?*","analyze_wildcard" : true}}}}} |
StartingWith | findByNameStartingWith | {"bool" : {"must" : {"field" : {"name" : {"query" : "?*","analyze_wildcard" : true}}}}} |
EndingWith | findByNameEndingWith | {"bool" : {"must" : {"field" : {"name" : {"query" : "*?","analyze_wildcard" : true}}}}} |
Contains/Containing | findByNameContaining | {"bool" : {"must" : {"field" : {"name" : {"query" : "**?**","analyze_wildcard" : true}}}}} |
In | findByNameIn(Collection | {"bool" : {"must" : {"bool" : {"should" : [ {"field" : {"name" : "?"}}, {"field" : {"name" : "?"}} ]}}}} |
NotIn | findByNameNotIn(Collection | {"bool" : {"must_not" : {"bool" : {"should" : {"field" : {"name" : "?"}}}}}} |
Near | findByStoreNear | Not Supported Yet ! |
True | findByAvailableTrue | {"bool" : {"must" : {"field" : {"available" : true}}}} |
False | findByAvailableFalse | {"bool" : {"must" : {"field" : {"available" : false}}}} |
OrderBy | findByAvailableTrueOrderByNameDesc | {"sort" : [{ "name" : {"order" : "desc"} }],"bool" : {"must" : {"field" : {"available" : true}}}} |
如:
import com.springsecurity.domain.ESBook; import org.springframework.data.domain.Pageable; import org.springframework.data.elasticsearch.repository.ElasticsearchRepository; import org.springframework.stereotype.Repository; import java.util.List; /** * @author 阿水 * @create 2023-04-13 11:05 */ @Repository //看实体类Id索引是什么类型 我这里是String public interface ESBookRepstitory extends ElasticsearchRepository{ /** * 根据描述查询书籍,带分页的 * @param description * @return */ List findESBookByDescription(String description, Pageable variable); /** * 根据作者和描述和标题查 */ List queryESBookByAuthorAndDescriptionOrTitle(String author,String description,String title); /** * 根据书的价格范围查询 */ List queryESBookByPriceBetween(Float price1,Float price2); }
@Test void esQueryCondition() { Sort sort = Sort.by(Sort.Order.desc("id")); PageRequest pageRequest = PageRequest.of(0, 2, sort); ListEBooks = bookByESRepstitory.findESBookByDescription("我",pageRequest); for (ESBook bookByE : EBooks) { System.out.println(bookByE); } } @Test void esQueryCondition2() { List esBooks = bookByESRepstitory.queryESBookByAuthorAndDescriptionOrTitle("盖伦", "哈嗨", "程序"); for (ESBook book : esBooks) { System.out.println(book); } } @Test void esQueryCondition3() { List esBooks = bookByESRepstitory.queryESBookByPriceBetween(18.88F,77.88F); for (ESBook book : esBooks) { System.out.println(book); } }
@Autowired private ElasticsearchRestTemplate restTemplate;
QueryBuilders.queryStringQuery() #指定字符串作为关键词查询,关键词支持分词 QueryBuilders.queryStringQuery("华为手机").defaultField("description"); //不指定feild,查询范围为所有feild QueryBuilders.queryStringQuery("华为手机"); //指定多个feild QueryBuilders.queryStringQuery("华为手机").field("title").field("description"); QueryBuilders.boolQuery #子方法must可多条件联查 QueryBuilders.termQuery #精确查询指定字段不支持分词 QueryBuilders.termQuery("description", "华为手机") QueryBuilders.matchQuery #按分词器进行模糊查询支持分词 QueryBuilders.matchQuery("description", "华为手机") QueryBuilders.rangeQuery #按指定字段进行区间范围查询 - `QueryBuilders.boolQuery()` - `QueryBuilders.boolQuery().must()`:相当于 and - `QueryBuilders.boolQuery().should()`:相当于 or - `QueryBuilders.boolQuery().mustNot()`:相当于 not - —————————————————————————————————————————————————————————————————————————————————————————————————————— @Test void naticeQuery() { NativeSearchQuery nativeSearchQuery = new NativeSearchQueryBuilder() //.withQuery(QueryBuilders.queryStringQuery("山巅哈哈").defaultField("description")) //多条件查询 .withQuery(QueryBuilders.boolQuery() .must(QueryBuilders.queryStringQuery("山巅哈哈").defaultField("description")) .should(QueryBuilders.queryStringQuery("宝石").defaultField("title")) ) .withPageable(PageRequest.of(0, 2)) .build(); SearchHitssearch = restTemplate.search(nativeSearchQuery, ESBook.class); List > searchHits = search.toList(); for (SearchHit searchHit : searchHits) { System.out.println(searchHit); } }
举个例子:
场景一:对外暴露的数据(数据量大的)的用es,如果不需要对外暴露,不需要全文检索的话,那么直接从数据查,所以做项目分析数据分成2块(哪些数据需要放es,从es查,哪些不需要)
场景二:作为mysql的外置索引,把作为数据库查询条件的列数据放到es里面,这样在查询的时候,先从es查询出符合条件的id,然后根据id去数据库查,数据维护大,一旦es宕机,就麻烦了