Elastic Search搜索引擎在SpringBoot中的实践

• ES版本：5.3.0
• spring bt版本：1.5.9

首先当然需要安装好elastic search环境，最好再安装上可视化插件 elasticsearch-head来便于我们直观地查看数据。

当然这部分可以参考本人的帖子：
《centos7上elastic search安装填坑记》
https://www.jianshu.com/p/04f4d7b4a1d3

我的ES安装在http://113.209.119.170:9200/这个地址（该地址需要配到springboot项目中去）

这部分没有特殊要交代的，但有几个注意点一定要当心

• 注意在新建项目时记得勾选web和NoSQL中的Elasticsearch依赖，来张图说明一下吧：

项目自动生成以后pom.xml中会自动添加spring-boot-starter-data-elasticsearch的依赖：

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

• 本项目中我们使用开源的基于restful的es java客户端jest，所以还需要在pom.xml中添加jest依赖：

      <dependency>
          <groupId>io.searchbox</groupId>
          <artifactId>jest</artifactId>
      </dependency>

• 除此之外还必须添加jna的依赖：

      <dependency>
          <groupId>net.java.dev.jna</groupId>
          <artifactId>jna</artifactId>
      </dependency>

否则启动spring项目的时候会报JNA not found. native methods will be disabled.的错误：

• 项目的配置文件application.yml中需要把es服务器地址配置对

  
  server:
  port: 6325

spring:
elasticsearch:
jest:
uris:

• http://113.209.119.170:9200 # ES服务器的地址！
  read-timeout: 5000

我的项目代码组织如下：

各部分代码详解如下，注释都有：

• Entity.java

package com.hansonwang99.springboot_es_demo.entity;
import java.io.Serializable;
import org.springframework.data.elasticsearch.annotations.Document;

public class Entity implements Serializable{

    private static final long serialVersionUID = -763638353551774166L;

    public static final String INDEX_NAME = "index_entity";

    public static final String TYPE = "tstype";

    private Long id;

    private String name;

    public Entity() {
        super();
    }

    public Entity(Long id, String name) {
        this.id = id;
        this.name = name;
    }

    public Long getId() {
        return id;
    }

    public void setId(Long id) {
        this.id = id;
    }

    public String getName() {
        return name;
    }

    public void setName(String name) {
        this.name = name;
    }

}

• TestService.java

package com.hansonwang99.springboot_es_demo.service;

import com.hansonwang99.springboot_es_demo.entity.Entity;

import java.util.List;

public interface TestService {

    void saveEntity(Entity entity);

    void saveEntity(List<Entity> entityList);

    List<Entity> searchEntity(String searchContent);
}

• TestServiceImpl.java

package com.hansonwang99.springboot_es_demo.service.impl;

import java.io.IOException;
import java.util.List;

import com.hansonwang99.springboot_es_demo.entity.Entity;
import com.hansonwang99.springboot_es_demo.service.TestService;
import org.elasticsearch.index.query.QueryBuilders;
import org.elasticsearch.search.builder.SearchSourceBuilder;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Service;
import io.searchbox.client.JestClient;
import io.searchbox.client.JestResult;
import io.searchbox.core.Bulk;
import io.searchbox.core.Index;
import io.searchbox.core.Search;

@Service
public class TestServiceImpl implements TestService {

    private static final Logger LOGGER = LoggerFactory.getLogger(TestServiceImpl.class);

    @Autowired
    private JestClient jestClient;

    @Override
    public void saveEntity(Entity entity) {
        Index index = new Index.Builder(entity).index(Entity.INDEX_NAME).type(Entity.TYPE).build();
        try {
            jestClient.execute(index);
            LOGGER.info("ES 插入完成");
        } catch (IOException e) {
            e.printStackTrace();
            LOGGER.error(e.getMessage());
        }
    }

    /**
     * 批量保存内容到ES
     */
    @Override
    public void saveEntity(List<Entity> entityList) {
        Bulk.Builder bulk = new Bulk.Builder();
        for(Entity entity : entityList) {
            Index index = new Index.Builder(entity).index(Entity.INDEX_NAME).type(Entity.TYPE).build();
            bulk.addAction(index);
        }
        try {
            jestClient.execute(bulk.build());
            LOGGER.info("ES 插入完成");
        } catch (IOException e) {
            e.printStackTrace();
            LOGGER.error(e.getMessage());
        }
    }

    /**
     * 在ES中搜索内容
     */
    @Override
    public List<Entity> searchEntity(String searchContent){
        SearchSourceBuilder searchSourceBuilder = new SearchSourceBuilder();
        //searchSourceBuilder.query(QueryBuilders.queryStringQuery(searchContent));
        //searchSourceBuilder.field("name");
        searchSourceBuilder.query(QueryBuilders.matchQuery("name",searchContent));
        Search search = new Search.Builder(searchSourceBuilder.toString())
                .addIndex(Entity.INDEX_NAME).addType(Entity.TYPE).build();
        try {
            JestResult result = jestClient.execute(search);
            return result.getSourceAsObjectList(Entity.class);
        } catch (IOException e) {
            LOGGER.error(e.getMessage());
            e.printStackTrace();
        }
        return null;
    }
}

• EntityController.java

package com.hansonwang99.springboot_es_demo.controller;

import java.util.ArrayList;
import java.util.List;

import com.hansonwang99.springboot_es_demo.entity.Entity;
import com.hansonwang99.springboot_es_demo.service.TestService;
import org.apache.commons.lang.StringUtils;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RequestMethod;
import org.springframework.web.bind.annotation.RestController;

@RestController
@RequestMapping("/entityController")
public class EntityController {

    @Autowired
    TestService cityESService;

    @RequestMapping(value="/save", method=RequestMethod.GET)
    public String save(long id, String name) {
        System.out.println("save 接口");
        if(id>0 && StringUtils.isNotEmpty(name)) {
            Entity newEntity = new Entity(id,name);
            List<Entity> addList = new ArrayList<Entity>();
            addList.add(newEntity);
            cityESService.saveEntity(addList);
            return "OK";
        }else {
            return "Bad input value";
        }
    }

    @RequestMapping(value="/search", method=RequestMethod.GET)
    public List<Entity> save(String name) {
        List<Entity> entityList = null;
        if(StringUtils.isNotEmpty(name)) {
            entityList = cityESService.searchEntity(name);
        }
        return entityList;
    }
}

增加几条数据，可以使用postman工具，也可以直接在浏览器中输入，如增加以下5条数据：

http://localhost:6325/entityController/save?id=1&name=南京中山陵
http://localhost:6325/entityController/save?id=2&name=中国南京师范大学
http://localhost:6325/entityController/save?id=3&name=南京夫子庙
http://localhost:6325/entityController/save?id=4&name=杭州也非常不错
http://localhost:6325/entityController/save?id=5&name=中国南边好像没有叫带京字的城市了

数据插入效果如下（使用可视化插件elasticsearch-head观看）：

我们来做一下搜索的测试：例如我要搜索关键字“南京”
我们在浏览器中输入：

http://localhost:6325/entityController/search?name=南京

搜索结果如下：

刚才插入的5条记录中包含关键字“南京”的四条记录均被搜索出来了！

当然这里用的是standard分词方式，将每个中文都作为了一个term，凡是包含“南”、“京”关键字的记录都被搜索了出来，只是评分不同而已，当然还有其他的一些分词方式，此时需要其他分词插件的支持，此处暂不涉及，后文中再做探索。