使用JAVA操作ElasticSearch( Spring Data ElasticSearch)

Spring Data是一个用于简化数据库访问，并支持云服务的开源框架。其主要目标是使得对数据的访问变得方便快捷，并支持map-reduce框架和云计算数据服务。 Spring Data可以极大的简化JPA的写法，可以在几乎不用写实现的情况下，实现对数据的访问和操作。除了CRUD外，还包括如分页、排序等一些常用的功能。

笔者的ElasticSearch集群的版本是6.2.4,导入spring-data-elasticsearch的maven依赖也是3.1.5.RELEASE,不同版本的api可能会有差异

一:准备maven依赖

 <!--elasticsearch核心依赖-->
        <dependency>
            <groupId>org.elasticsearch</groupId>
            <artifactId>elasticsearch</artifactId>
            <version>6.2.4</version>
        </dependency>
        <!--elasticsearch客户端-->
        <dependency>
            <groupId>org.elasticsearch.client</groupId>
            <artifactId>transport</artifactId>
            <version>6.2.4</version>
        </dependency>
        <!--日志-->
        <dependency>
            <groupId>org.apache.logging.log4j</groupId>
            <artifactId>log4j-to-slf4j</artifactId>
            <version>2.9.1</version>
        </dependency>
        <dependency>
            <groupId>org.slf4j</groupId>
            <artifactId>slf4j-api</artifactId>
            <version>1.7.24</version>
        </dependency>
        <dependency>
            <groupId>org.slf4j</groupId>
            <artifactId>slf4j-simple</artifactId>
            <version>1.7.21</version>
        </dependency>

        <dependency>
            <groupId>log4j</groupId>
            <artifactId>log4j</artifactId>
            <version>1.2.12</version>
        </dependency>
        <!--单元测试-->
        <dependency>
            <groupId>junit</groupId>
            <artifactId>junit</artifactId>
            <version>4.12</version>
            <scope>compile</scope>
        </dependency>
       
        <!--实体类简化工具-->
        <dependency>
            <groupId>org.projectlombok</groupId>
            <artifactId>lombok</artifactId>
            <version>1.16.18</version>
        </dependency>

        <!--springframework-->
        <dependency>
            <groupId>org.springframework</groupId>
            <artifactId>spring-test</artifactId>
            <version>5.2.3.RELEASE</version>
        </dependency>
        <!--spring-data-elasticsearch-->
        <dependency>
            <groupId>org.springframework.data</groupId>
            <artifactId>spring-data-elasticsearch</artifactId>
            <version>3.1.5.RELEASE</version>
            <exclusions>
                <exclusion>
                    <groupId>org.elasticsearch.plugin</groupId>
                    <artifactId>transport‐netty4‐client</artifactId>
                </exclusion>
            </exclusions>
        </dependency>

二:创建实体

package com.yjc.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;

//lombok相当于get,set,toSting等一系列方法
@Data
//代表文档对象(索引库,类型)
@Document(indexName = "myindex2",type = "article")
public class Article {
    //文档主键,唯一
    @Id
    //store是否存储(默认false),index是否分词(默认true),type类型
    @Field(store = true,index = false,type = FieldType.Integer)
    private Integer id;
    //下面配置代表 进行存储并以ik_smart方式分词,(默认开启分词)保持的类型为text,进行查询的时候按照ik_smart方式进行分词
    @Field(store = true,analyzer ="ik_smart",searchAnalyzer = "ik_smart",type = FieldType.Text)
    private String title;
    //下面配置代表 进行存储并以ik_smart方式分词,保持的类型为text,进行查询的时候按照ik_smart方式进行分词
    @Field(store = true,analyzer ="ik_smart",searchAnalyzer = "ik_smart",type = FieldType.Text)
    private String content;
}

三:创建DAO和Service

ArticleDao

package com.yjc.dao;

import com.yjc.entity.Article;
import org.springframework.data.domain.Page;
import org.springframework.data.domain.Pageable;
import org.springframework.data.elasticsearch.repository.ElasticsearchRepository;
import org.springframework.stereotype.Repository;

import java.util.List;

@Repository
/**
 * ElasticsearchRepository<要操作的实体类,ID在实体类中类型>
 * */
public interface ArticleDao extends ElasticsearchRepository<Article,Integer> {
    //根据标题查询
    List<Article> findByTitle(String condition);
    //根据标题查询(含分页)
    Page<Article> findByTitle(String condition, Pageable pageable);
    //根据id
    List<Article> findById(String condition);
}

ArticleService

package com.yjc.service;

import com.yjc.entity.Article;
import org.springframework.data.domain.Page;
import org.springframework.data.domain.Pageable;

import java.util.List;

public interface ArticleService {
    //添加
    void save(Article article);
    //删除
    void delete(Article article);
    //查询全部
    Iterable<Article> findAll();
    //分页查询
    Page<Article> findAll(Pageable pageable);

    //根据标题查询
    List<Article> findByTitle(String condition);
    //根据标题查询(含分页)
    Page<Article> findByTitle(String condition, Pageable pageable);
    //根据内容搜索并分页
    List<Article> findById(String condition);
}

ArticleServiceImpl

package com.yjc.service.impl;

import com.yjc.dao.ArticleDao;
import com.yjc.entity.Article;
import com.yjc.service.ArticleService;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.data.domain.Page;
import org.springframework.data.domain.Pageable;
import org.springframework.stereotype.Service;
import java.util.List;

@Service
public class ArticleServiceImpl implements ArticleService {
   @Autowired
    ArticleDao articleDao;
    @Override
    public void save(Article article) {
        articleDao.save(article);
    }

    @Override
    public void delete(Article article) {
        articleDao.delete(article);
    }

    @Override
    public Iterable<Article> findAll() {
        return articleDao.findAll();
    }

    @Override
    public Page<Article> findAll(Pageable pageable) {
        return articleDao.findAll(pageable);
    }

    @Override
    public List<Article> findByTitle(String condition) {
        return articleDao.findByTitle(condition);
    }

    @Override
    public Page<Article> findByTitle(String condition, Pageable pageable) {
        return articleDao.findByTitle(condition,pageable);
    }

    @Override
    public List<Article> findById(String condition) {
        return articleDao.findById(condition);
    }
}

四:创建Spring的核心配置文件

applicationContext.xml,注意更换命名空间

<?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:context="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 ">
    <!--创建包扫描器,扫描Dao,自动创建实例-->
    <elasticsearch:repositories base-package="com.yjc.dao"/>
    <!--扫描Service-->
    <context:component-scan base-package="com.yjc.service"/>
    <!--配置es的连接-->
    <elasticsearch:transport-client id="client" cluster-nodes="192.168.118.3:9300" cluster-name="elasticsearch"/>
    <!--es模板对象-->
    <bean id="elasticsearchTemplate" class="org.springframework.data.elasticsearch.core.ElasticsearchTemplate">
        <constructor-arg name="client" ref="client"/>
    </bean>
</beans>

五:测试

package com.yjc.test;

import com.yjc.entity.Article;
import com.yjc.service.ArticleService;
import org.elasticsearch.client.transport.TransportClient;
import org.junit.Test;
import org.junit.runner.RunWith;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.data.domain.Page;
import org.springframework.data.domain.PageRequest;
import org.springframework.data.domain.Pageable;
import org.springframework.data.elasticsearch.core.ElasticsearchTemplate;
import org.springframework.test.context.ContextConfiguration;
import org.springframework.test.context.junit4.SpringJUnit4ClassRunner;

import java.util.List;


@RunWith(SpringJUnit4ClassRunner.class)
//启动单元测试的时候加载的配置文件
@ContextConfiguration(locations = "classpath:applicationContext.xml")
public class SpringDataESTest {
    @Autowired
    ArticleService articleService;

    //注入连接对象
    @Autowired
    TransportClient client;
    //注入模板对象
    @Autowired
    ElasticsearchTemplate elasticsearchTemplate;

    @Test
    //创建索引
    public void createIndex() {
        //配置在实体类中已经配置好了,直接创建并添加映射
        elasticsearchTemplate.createIndex(Article.class);
        elasticsearchTemplate.putMapping(Article.class);
    }

    @Test
    //保存文档
    public void saveArticle() {
        Article article = new Article();
        article.setId(101);
        article.setTitle("测试SpringData ElasticSearch");
        article.setContent("Spring Data ElasticSearch 基于 spring data API 简化 elasticSearch操 作，将原始操作elasticSearch的客户端API 进行封装 \n" + " Spring Data为Elasticsearch Elasticsearch项目提供集成搜索引擎");
        articleService.save(article);
    }

    @Test
    //修改文档
    public void update() {
        Article article = new Article();
        article.setId(100);
        article.setTitle("修改SpringData ElasticSearch");
        article.setContent("修改Spring Data ElasticSearch 基于 spring data API 简化 elasticSearch操 作，将原始操作elasticSearch的客户端API 进行封装 \n" + " Spring Data为Elasticsearch Elasticsearch项目提供集成搜索引擎");
        articleService.save(article);
    }
    @Test
    //删除文档
    public  void delete(){
        Article article = new Article();
        article.setId(100);
        articleService.delete(article);
    }

    @Test
    //分页查询
    public void findAllPage(){
        Pageable pageable=PageRequest.of(0,10);
        Page<Article> all = articleService.findAll(pageable);
        for (Article article:all.getContent()){
            System.out.println(article);
        }

    }
    @Test
    //带条件查询
    public  void findByTitle(){
        List<Article> articles = articleService.findByTitle("测试");
        for (Article article:articles){
            System.out.println(article);
        }
    }
    @Test
    //待条件查询加分页
    public void findByTitlePage(){
        Pageable pageable=PageRequest.of(0,1);
        Page<Article> articles = articleService.findByTitle("引擎", pageable);
        for (Article article:articles.getContent()){
            System.out.println(article);
        }
    }

    @Test
    //根据id进行查询
    public void findByContent(){
        List<Article> articles = articleService.findById("100");
        for (Article article:articles){
            System.out.println(article);
        }
    }
}

Spring Data ElasticSearch中带条件查询是根据Dao层的方法名来判断去哪个域中去搜索数据,常用的命名规范如下