ElasticsearchRestTemplate 和ElasticsearchRepository 的使用

操作ElasticSearch的数据，有两种方式一种是 ElasticsearchRepository 接口，另一种是ElasticsearchTemplate接口。SpringData对ES的封装ElasticsearchRestTemplate类，可直接使用，此类在ElasticsearchRestTemplate基础上进行性一定程度的封装，使用起来更方便灵活，拓展性更强。ElasticsearchRepository可以被继承操作ES，是SpringBoot对ES的高度封装，操作最为方便，但牺牲了灵活性。

** Spring boot 和Elasticsearch版本关系：**

一、使用ElasticsearchRestTemplate类

** 1.引用Maven类库**

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

2. 配置文件application.yml

spring:
  elasticsearch:
    rest:
      uris: http://192.168.10.202:9200
      connection-timeout: 1s
      read-timeout: 1m
      username: elastic
      password: elastic

注意，如果es资源没有开启x-pack安全插件的话，可以不加username和password（因为默认是没有的）。

3.创建实体类（用于JSON文档对象的转换）

import com.fasterxml.jackson.annotation.JsonFormat;
import lombok.Data;
import org.springframework.data.annotation.Id;
import org.springframework.data.elasticsearch.annotations.DateFormat;
import org.springframework.data.elasticsearch.annotations.Document;
import org.springframework.data.elasticsearch.annotations.Field;
import org.springframework.data.elasticsearch.annotations.FieldType;
import java.time.LocalDate;
import java.time.LocalDateTime;
/**
 * @author Sinbad
 * @description: 测试ES对象<br />
 * @date 2022/8/26 17:12
 */
@Document(indexName = "mysql-test")
@Data
public class TestEsEntity {
    @Id  
    Long id;
    @Field(type = FieldType.Text, name = "addr")
    String addr;
    @Field(type = FieldType.Text, name = "name")
    String name;
    @Field(type = FieldType.Date, name = "birthday", pattern = "yyyy-MM-dd")
    LocalDate birthday;
    @JsonFormat(pattern = "yyyy-MM-dd HH:mm:ss", timezone = "GMT+8",locale = "zh_CN")
    @Field(type = FieldType.Date, name = "create_time", pattern = "yyyy-MM-dd HH:mm:ss",format =DateFormat.custom )
    LocalDateTime createTime;
}

@Document注解：表示对应一个索引名相关的文档
@Data注解：lombok的，为类提供读写属性, 此外还提供了 equals()、hashCode()、toString() 方法
@Id 注解：表示文档的ID字段
@Field注解：文档字段的注解，对于日期含时间的字段，要写patten和format，不然会无法更新文档对象
@JsonFormat注解：将文档转换成JSON返回给前端时用到
注意日期类型字段不要用java.util.Date类型，要用java.time.LocalDate或java.time.LocalDateTime类型。

** 测试实例：**

import com.hkyctech.commons.base.entity.JsonResult;
import com.hkyctech.tu.core.vo.TestEsEntity ;
import lombok.extern.slf4j.Slf4j;
import org.elasticsearch.index.query.BoolQueryBuilder;
import org.elasticsearch.index.query.QueryBuilders;
import org.elasticsearch.search.fetch.subphase.highlight.HighlightBuilder;
import org.springframework.data.domain.PageRequest;
import org.springframework.data.elasticsearch.core.ElasticsearchRestTemplate;
import org.springframework.data.elasticsearch.core.query.NativeSearchQuery;
import org.springframework.data.elasticsearch.core.query.NativeSearchQueryBuilder;
import org.springframework.data.elasticsearch.core.query.Query;
import org.springframework.stereotype.Service;
import javax.annotation.Resource;

 
@Slf4j
@Service
public class ElasticSearchServiceImpl {
    @Resource
    ElasticsearchRestTemplate elasticsearchTemplate; //直接注入就可以用了
    /***
     * @description 查询全部数据
     */
    public Object testSearchAll(){
        Query query=elasticsearchTemplate.matchAllQuery();
        return elasticsearchTemplate.search(query, TestEsEntity .class);
    }

    /***
    * @description  精确查询地址字段
    * @param keyword 搜索关键字
    */
    public Object testSearchAddr(String keyword) {
        NativeSearchQuery nativeSearchQuery = new NativeSearchQueryBuilder()
                //查询条件
                .withQuery(QueryBuilders.queryStringQuery(keyword).defaultField("addr"))
                //分页
                .withPageable(PageRequest.of(0, 10))
                //高亮字段显示
                .withHighlightFields(new HighlightBuilder.Field(keyword))
                .build();
        return elasticsearchTemplate.search(nativeSearchQuery, TestEsEntity .class);
    }

    /***
    * @description 组合查询，查询关键词不分词，关系and
    */
    public Object testComboSearchAnd(){
        BoolQueryBuilder esQuery=QueryBuilders.boolQuery()
                .must(QueryBuilders.termQuery("addr", "深圳"))
                .must(QueryBuilders.termQuery("addr", "广东"));

        NativeSearchQuery nativeSearchQuery = new NativeSearchQueryBuilder()
                //查询条件
                .withQuery(esQuery)
                //分页
                .withPageable(PageRequest.of(0, 10))
                .build();
        return elasticsearchTemplate.search(nativeSearchQuery, TestEsEntity .class);
    }

    /***
     * @description 组合查询，查询关键词不分词，关系or
     */
    public Object testComboSearchOr(){
        BoolQueryBuilder esQuery=QueryBuilders.boolQuery()
                .should(QueryBuilders.termQuery("addr", "深圳"))
                .should(QueryBuilders.termQuery("addr", "广东"));

        NativeSearchQuery nativeSearchQuery = new NativeSearchQueryBuilder()
                //查询条件
                .withQuery(esQuery)
                //分页
                .withPageable(PageRequest.of(0, 10))
                .build();
        return elasticsearchTemplate.search(nativeSearchQuery, TestEsEntity .class);
    }

    /***
    * @description  索引或更新文档
    * @param vo 文档对象
    */
    public JsonResult testPutDocument(TestEsEntity  vo){
        try {
            Object data = elasticsearchTemplate.save(vo);
            return JsonResult.getSuccessResult(data,"更新成功");
        }catch (Exception e){
            // 看http请求响应日志其实操作成功了，但是会报解析出错，可能是spring的bug，这里拦截一下
            String message=e.getMessage();
            if(message.indexOf("response=HTTP/1.1 200 OK")>0 || message.indexOf("response=HTTP/1.1 201 Created")>0){
                return JsonResult.getSuccessResult("更新成功");
            }
            return JsonResult.getFailResult(e.getStackTrace(),e.getMessage());
        }
    }

    /***
    * @description  删除文档
    * @param id 文档ID
    */
    public JsonResult deleteDocument(String id){
        try {
            elasticsearchTemplate.delete(id, TestEsEntity .class);
            return JsonResult.getSuccessResult("删除成功");
        }catch (Exception e){
            String message=e.getMessage();
            // 看http请求响应日志其实操作成功了，但是会报解析出错，可能是spring的bug，这里拦截一下
            if(message.indexOf("response=HTTP/1.1 200 OK")>0 ){
                return JsonResult.getSuccessResult("删除成功");
            }
            return JsonResult.getFailResult(e.getStackTrace(),e.getMessage());
        }
    }
}

二、使用ElasticsearchRepository 类

1.引用Maven类库

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

2. 配置文件application.yml

spring:
  elasticsearch:
    rest:
      uris: http://192.168.10.202:9200
      connection-timeout: 1s
      read-timeout: 1m
      username: elastic
      password: elastic

** 3. ElasticsearchRepository接口的源码 **

package org.springframework.data.elasticsearch.repository;
 
import java.io.Serializable;
 
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.SearchQuery;
import org.springframework.data.repository.NoRepositoryBean;
 
@NoRepositoryBean
public interface ElasticsearchRepository<T, ID extends Serializable> extends ElasticsearchCrudRepository<T, ID> {
 
    <S extends T> S index(S entity);
 
    Iterable<T> search(QueryBuilder query);
 
    Page<T> search(QueryBuilder query, Pageable pageable);
 
    Page<T> search(SearchQuery searchQuery);
 
    Page<T> searchSimilar(T entity, String[] fields, Pageable pageable);
 
    void refresh();
 
    Class<T> getEntityClass();
}
 

** 4.CrudRepository 源码**

package org.springframework.data.repository;
 
import java.util.Optional;
 
/**
 * Interface for generic CRUD operations on a repository for a specific type.
 *
 * @author Oliver Gierke
 * @author Eberhard Wolff
 */
@NoRepositoryBean
public interface CrudRepository<T, ID> extends Repository<T, ID> {
 
    /**
     * Saves a given entity. Use the returned instance for further operations as the save operation might have changed the
     * entity instance completely.
     *
     * @param entity must not be {@literal null}.
     * @return the saved entity will never be {@literal null}.
     */
    <S extends T> S save(S entity);
 
    /**
     * Saves all given entities.
     *
     * @param entities must not be {@literal null}.
     * @return the saved entities will never be {@literal null}.
     * @throws IllegalArgumentException in case the given entity is {@literal null}.
     */
    <S extends T> Iterable<S> saveAll(Iterable<S> entities);
 
    /**
     * Retrieves an entity by its id.
     *
     * @param id must not be {@literal null}.
     * @return the entity with the given id or {@literal Optional#empty()} if none found
     * @throws IllegalArgumentException if {@code id} is {@literal null}.
     */
    Optional<T> findById(ID id);
 
    /**
     * Returns whether an entity with the given id exists.
     *
     * @param id must not be {@literal null}.
     * @return {@literal true} if an entity with the given id exists, {@literal false} otherwise.
     * @throws IllegalArgumentException if {@code id} is {@literal null}.
     */
    boolean existsById(ID id);
 
    /**
     * Returns all instances of the type.
     *
     * @return all entities
     */
    Iterable<T> findAll();
 
    /**
     * Returns all instances of the type with the given IDs.
     *
     * @param ids
     * @return
     */
    Iterable<T> findAllById(Iterable<ID> ids);
 
    /**
     * Returns the number of entities available.
     *
     * @return the number of entities
     */
    long count();
 
    /**
     * Deletes the entity with the given id.
     *
     * @param id must not be {@literal null}.
     * @throws IllegalArgumentException in case the given {@code id} is {@literal null}
     */
    void deleteById(ID id);
 
    /**
     * Deletes a given entity.
     *
     * @param entity
     * @throws IllegalArgumentException in case the given entity is {@literal null}.
     */
    void delete(T entity);
 
    /**
     * Deletes the given entities.
     *
     * @param entities
     * @throws IllegalArgumentException in case the given {@link Iterable} is {@literal null}.
     */
    void deleteAll(Iterable<? extends T> entities);
 
    /**
     * Deletes all entities managed by the repository.
     */
    void deleteAll();
}
 

5. 查询查找策略

5.1存储库方法可以定义为具有以下返回类型，用于返回多个元素：

• List<T>
• Stream<T>
• SearchHits<T>
• List<SearchHit<T>>
• Stream<SearchHit<T>>
• SearchPage<T>

5.2 使用@Query注解

使用@query注释对方法声明query。

interface BookRepository extends ElasticsearchRepository<Book, String> {
    @Query("{\"match\": {\"name\": {\"query\": \"?0\"}}}")
    Page<Book> findByName(String name,Pageable pageable);
}

设置为注释参数的字符串必须是有效的 Elasticsearch JSON 查询。 它将作为查询元素的值发送到Easticsearch;例如，如果使用参数 John 调用函数，它将生成以下查询正文：

{
  "query": {
    "match": {
      "name": {
        "query": "John"
      }
    }
  }
}

对

@Query

采用集合参数的方法进行注释

@Query("{\"ids\": {\"values\": ?0 }}")
List<SampleEntity> getByIds(Collection<String> ids);

将进行ID查询以返回所有匹配的文档。因此，调用List为[“id1”、“id2”、“id3”]的方法将生成查询主体

{
  "query": {
    "ids": {
      "values": ["id1", "id2", "id3"]
    }
  }
}

6.开发实例：

public interface LogRepository extends ElasticsearchRepository<Log, String> {
    /**
     * 定义一个方法查询：根据title查询es
     *
     * 原因：  ElasticsearchRepository会分析方法名,参数对应es中的field（这就是灵活之处）
     * @param title
   
     */

    List<Log> findBySummary(String summary);
    List<Log> findByTitle(String title);

    /**
     * 定义一个方法查询： 根据title，content查询es
     */
    List<Log> findByTitleAndContent(String title, String content);

}
 

   @PostMapping("save")
    public void save(@Validated @RequestBody Log req){
        Log dto = new Log();
        dto.setTitle(req.getTitle());
        dto.setSummary(req.getSummary());
        dto.setContent(req.getContent());
        dto.setCreateTime(new Date());
        dto.setId(req.getId());      
        LogRepository.save(dto);
        return ;
        } 

    @PostMapping("testTitle")
    public void testSearchTitle(@Validated @RequestBody Log req){
        List<Log> searchResult = logRepository.findByTitle(req.getMobileType());
        Iterator<Log> iterator = searchResult.iterator();
        while(iterator.hasNext()){
            System.out.println(iterator.next());
        }
        System.out.println("sa");
        return;
    }
 

官网：Spring Data Elasticsearch - Reference Documentation