学习ElasticSearch：Spring Data ElasticSearch

1, engineering structures

• Import dependence: Here is an ordinary maven project

<?xml version="1.0" encoding="UTF-8"?>
<project xmlns="http://maven.apache.org/POM/4.0.0"
         xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
         xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
    <modelVersion>4.0.0</modelVersion>

    <groupId>com.es</groupId>
    <artifactId>springdataes</artifactId>
    <version>1.0-SNAPSHOT</version>
    <properties>
        <maven.compiler.source>1.9</maven.compiler.source>
        <maven.compiler.target>1.9</maven.compiler.target>
    </properties>
    <dependencies>
        <dependency>
            <groupId>org.elasticsearch</groupId>
            <artifactId>elasticsearch</artifactId>
            <version>5.6.8</version>
        </dependency>
        <dependency>
            <groupId>org.elasticsearch.client</groupId>
            <artifactId>transport</artifactId>
            <version>5.6.8</version>
        </dependency>
        <dependency>
            <groupId>com.fasterxml.jackson.core</groupId>
            <artifactId>jackson-databind</artifactId>
            <version>2.8.1</version>
        </dependency>
        <dependency>
            <groupId>com.fasterxml.jackson.core</groupId>
            <artifactId>jackson-annotations</artifactId>
            <version>2.8.1</version>
        </dependency>
        <dependency>
            <groupId>org.springframework.data</groupId>
            <artifactId>spring-data-elasticsearch</artifactId>
            <version>3.0.5.RELEASE</version>
            <exclusions>
                <exclusion>
                    <groupId>org.elasticsearch.plugin</groupId>
                    <artifactId>transport-netty4-client</artifactId>
                </exclusion>
            </exclusions>
        </dependency>
        <dependency>
            <groupId>org.springframework</groupId>
            <artifactId>spring-test</artifactId>
            <version>5.0.4.RELEASE</version>
        </dependency>
    </dependencies>

</project>

• applicationContext.xml: here belong to the spring configuration

<?xml version="1.0" encoding="UTF-8"?>
<beans xmlns="http://www.springframework.org/schema/beans"
       xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
       xmlns:content="http://www.springframework.org/schema/context"
       xmlns:elasticsearch="http://www.springframework.org/schema/data/elasticsearch"
       xsi:schemaLocation="
        http://www.springframework.org/schema/beans
        http://www.springframework.org/schema/beans/spring-beans.xsd
        http://www.springframework.org/schema/context
        http://www.springframework.org/schema/context/spring-context.xsd
        http://www.springframework.org/schema/data/elasticsearch
        http://www.springframework.org/schema/data/elasticsearch/spring-elasticsearch-1.0.xsd">

<!--    配置es客户端-->
    <elasticsearch:transport-client id="esClient" cluster-name="my-elasticsearch"
                                    cluster-nodes="127.0.0.1:9301,127.0.0.1:9302,127.0.0.1:9303"/>
<!--    配置包扫描器-->
    <elasticsearch:repositories base-package="com.es.dao"/>
<!--    配置封装类-->
    <bean id="elasticsearchTemplate" class="org.springframework.data.elasticsearch.core.ElasticsearchTemplate">
       <constructor-arg name="client" ref="esClient"/>

    </bean>
</beans>

2 Create Entity class, dao

Entity

package com.es.entity;

import lombok.Data;
import org.springframework.data.annotation.Id;
import org.springframework.data.elasticsearch.annotations.Document;
import org.springframework.data.elasticsearch.annotations.Field;
import org.springframework.data.elasticsearch.annotations.FieldType;

@Document(indexName = "spring-es-blog",type = "article")
@Data
public class Article {
    @Id
    @Field(type = FieldType.Long,store = true)
    private long id;
    @Field(type = FieldType.text,store = true,analyzer = "ik_smart")
    private String title;
    @Field(type = FieldType.text,store = true,analyzer = "ik_smart")
    private String content;
}

dao layer

• Interface inheritance ElasticsearchRepository

package com.es.dao;

import com.es.entity.Article;
import org.springframework.data.elasticsearch.repository.ElasticsearchRepository;

public interface ArticleDao extends ElasticsearchRepository<Article,Long> {
}

3, operation

import com.es.dao.ArticleDao;
import com.es.entity.Article;
import org.junit.Test;
import org.junit.runner.RunWith;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.data.elasticsearch.core.ElasticsearchTemplate;
import org.springframework.test.context.ContextConfiguration;
import org.springframework.test.context.junit4.SpringJUnit4ClassRunner;

import java.util.Optional;

/**
 * @ClassName SpringDataEsTest
 * @Description
 * @Author 戴书博
 * @Date 2019/12/2 23:31
 * @Version 1.0
 **/
@RunWith(SpringJUnit4ClassRunner.class)
@ContextConfiguration("classpath:applicationContext.xml")
public class SpringDataEsTest {

    @Autowired
    private ArticleDao articleDao;
    @Autowired
    private ElasticsearchTemplate template;

    /**
     * 创建索引库
     */
    @Test
    public void createIndex(){
        //创建索引、并配置映射关系。
        template.createIndex(Article.class);
        //仅配置映射
        template.putMapping(Article.class);
    }

    /**
     * 添加文档
     */
    @Test
    public void addDocument(){
        Article article = new Article();
        article.setId(1l);
        article.setTitle("三严三实”专题教育");
        article.setContent("2015年4月10日，中共中央办公厅印发《关于在县处级以上领导干部中开展“三严三实”专题教育方案》");
        //把文档写入索引库
        articleDao.save(article);
    }

    /**
     * 删除文档
     */
    @Test
    public void deleteDocument(){
        articleDao.deleteById(1l);
    }

    /**
     * 更新
     */
    @Test
    public void updateDocument(){
        //先删除
        //再添加
    }

    /**
     * 简单查询
     */
    @Test
    public void findAll(){
        Iterable<Article> articles =  articleDao.findAll();
        articles.forEach(a-> System.out.println(a));
    }

    /**
     * 根据id查询
     */
    @Test
    public void findById(){
        Optional<Article> optional = articleDao.findById(1l);
        Article article = optional.get();
    }
}

Custom query methods

• There is a custom query method of naming
  
• dao layer

package com.es.dao;

import com.es.entity.Article;
import org.springframework.data.elasticsearch.repository.ElasticsearchRepository;

import java.awt.print.Pageable;
import java.util.List;

/**
 * @ClassName ArticleDao
 * @Description
 * @Author 戴书博
 * @Date 2019/12/2 23:24
 * @Version 1.0
 **/
public interface ArticleDao extends ElasticsearchRepository<Article,Long> {
    /**
     * 根据标题查询
     */
    List<Article> findByTitle(String title);

    /**
     * 根据标题和内容查询
     */
    List<Article> findByContentAndTitle(String content,String title);

    /**
     * 分页查询
     */
    List<Article> findByContentAndTitle(String content, String title, Pageable pageable);

}

• Query methods

  /**
     * 根据id查询
     */
    @Test
    public void findById(){
        Optional<Article> optional = articleDao.findById(1l);
        Article article = optional.get();
    }

    @Test
    public void findByTitle(){
        List<Article> list = articleDao.findByTitle("哈哈");
        list.stream().forEach(a -> System.out.println(a));
    }

    @Test
    public void findByPage(){
        Pageable pageable = (Pageable) PageRequest.of(0,20);
        articleDao.findByContentAndTitle("ahh","dasda", pageable);
    }

• The principle is the content of the first search query word and then, between each word is and relationships.
• If you do not want and relationships, we need to use native query.

public void nativeSearchQuery(){
   //创建一个查询对象
    NativeSearchQuery query = new NativeSearchQueryBuilder()
            .withQuery(QueryBuilders.queryStringQuery("maven是一个").defaultField("title"))
            .withPageable(PageRequest.of(0,20)).build();
    //执行查询
     List<Article> list =  template.queryForList(query,Article.class);
}