springboot整合elasticsearch全文检索入门

只是简单的整合介绍

# 安装

下载elasticsearch与kibana https://www.elastic.co/start

# 依赖

springBootVersion = '2.0.5.RELEASE'
compile group: 'org.springframework.boot', name: 'spring-boot-starter-data-elasticsearch'
 //请与spring-boot-starter-data-elasticsearch的jar包版本一致
compile('org.elasticsearch.client:transport:5.6.11') 

springBoot 2.0.5.RELEASE 起步依赖的elasticsearch的版本是 5.6.11

# 配置

1. 可在application.yml中配置

spring:
  data:
    # 全文检索 elasticsearch
    elasticsearch:
      cluster-name: elasticsearch #节点名称
      cluster-nodes: 127.0.0.1:9300 #节点地址
      repositories:
        enabled: true

2. 也可以通过java代码进行配置

package com.futao.springmvcdemo.foundation.configuration

import org.elasticsearch.client.transport.TransportClient
import org.elasticsearch.common.settings.Settings
import org.elasticsearch.common.transport.InetSocketTransportAddress
import org.elasticsearch.transport.client.PreBuiltTransportClient
import org.springframework.context.annotation.Bean
import org.springframework.context.annotation.Configuration
import org.springframework.data.elasticsearch.repository.config.EnableElasticsearchRepositories
import java.net.InetAddress

/**
 * @author futao
 * Created on 2018/10/22.
 * ElasticSearch全文检索配置类
 * 可替代配置文件中的配置
 */
@Configuration
@EnableElasticsearchRepositories(basePackages = ["com.futao.springmvcdemo.dao"])
open class ElasticSearchConfiguration {

    @Bean
    open fun client(): TransportClient {
        val node = InetSocketTransportAddress(
                InetAddress.getByName("127.0.0.1"), 9300)
        val settings = Settings.builder()
                .put("cluster.name", "springboot-elasticsearch")    //集群名称可以在\elasticsearch\config\elasticsearch.yml中配置
                .build()
        return PreBuiltTransportClient(settings).addTransportAddress(node)
    }
}

# 名词解释

elasticsearch中的名词与mysql中的名字对比

# 使用

个人理解：相当于mysql的建表,程序跑起来之后会建立相应的index与type，后续程序中就可以使用该类型的index与type进行crud

package com.futao.springmvcdemo.model.entity;

import org.springframework.data.elasticsearch.annotations.Document;

/**
 * @author futao
 * Created on 2018/10/20.
 * 文章
 * indexName=database
 * type=table
 * row=document
 * colnum=field
 */
@Document(indexName = "futao", type = "article")
public class Article extends BaseEntity {
    /**
     * 标题
     */
    private String title;
    /**
     * 简介
     */
    private String description;
    /**
     * 内容
     */
    private String content;

    public String getTitle() {
        return title;
    }

    public void setTitle(String title) {
        this.title = title;
    }

    public String getDescription() {
        return description;
    }

    public void setDescription(String description) {
        this.description = description;
    }

    public String getContent() {
        return content;
    }

    public void setContent(String content) {
        this.content = content;
    }
}

# 插入数据

• Dao层

package com.futao.springmvcdemo.dao.impl

import com.futao.springmvcdemo.model.entity.Article
import org.springframework.data.elasticsearch.repository.ElasticsearchRepository

/**
 * @author futao
 * Created on 2018/10/22.
 */
interface ArticleSearchDao : ElasticsearchRepository<Article, String> {
}

• Service层

package com.futao.springmvcdemo.service.impl

import com.alibaba.fastjson.JSONObject
import com.futao.springmvcdemo.dao.ArticleDao
import com.futao.springmvcdemo.dao.impl.ArticleSearchDao
import com.futao.springmvcdemo.foundation.LogicException
import com.futao.springmvcdemo.model.entity.Article
import com.futao.springmvcdemo.model.entity.constvar.ErrorMessage
import com.futao.springmvcdemo.service.ArticleService
import com.futao.springmvcdemo.utils.currentTimeStamp
import com.futao.springmvcdemo.utils.getFieldName
import com.futao.springmvcdemo.utils.uuid
import org.elasticsearch.client.Client
import org.elasticsearch.index.query.QueryBuilders
import org.springframework.data.redis.core.RedisTemplate
import org.springframework.stereotype.Service
import javax.annotation.Resource

/**
 * @author futao
 * Created on 2018/10/20.
 */
@Service
open class ArticleServiceImpl : ArticleService {
    @Resource
    private lateinit var elasticsearch: ArticleSearchDao

    @Resource
    private lateinit var client: Client

    override fun list(): List<Article> {
        val list = articleDao.list()
        elasticsearch.saveAll(list)
        return list
    }
 /**
     * 全文检索
     */
    override fun search(key: String): ArrayList<Article> {
        val hits = client.prepareSearch("futao")
                .setTypes("article")
                .setQuery(
                        QueryBuilders
                                .boolQuery()
                                .should(QueryBuilders.matchQuery(Article::getContent.getFieldName(), key))
                                .should(QueryBuilders.matchQuery(Article::getTitle.getFieldName(), key))
                                .should(QueryBuilders.matchQuery(Article::getDescription.getFieldName(), key))

                )
                .execute()
                .actionGet()
                .hits
        val list: ArrayList<Article> = arrayListOf()
        hits.forEach { it -> list.add(JSONObject.parseObject(it.sourceAsString, Article::class.java)) }
        return list
    }
}

• controller层

package com.futao.springmvcdemo.controller.business;

import com.futao.springmvcdemo.model.entity.Article;
import com.futao.springmvcdemo.model.entity.SingleValueResult;
import com.futao.springmvcdemo.service.ArticleService;
import org.springframework.http.MediaType;
import org.springframework.web.bind.annotation.*;

import javax.annotation.Resource;
import java.util.List;

/**
 * @author futao
 * Created on 2018/10/20.
 */
@RestController
@RequestMapping(path = "article", produces = MediaType.APPLICATION_JSON_UTF8_VALUE)
public class ArticleController {
    @Resource
    private ArticleService articleService;

    /**
     * 新增文章
     *
     * @param title
     * @param desc
     * @param content
     * @return
     */
    @PostMapping(path = "add")
    public SingleValueResult add(
            @RequestParam("title") String title,
            @RequestParam("desc") String desc,
            @RequestParam("content") String content
    ) {
        articleService.add(title, desc, content);
        return new SingleValueResult("success");
    }

    /**
     * 文章列表
     *
     * @return
     */
    @GetMapping("list")
    public List<Article> list() {
        return articleService.list();
    }

    /**
     * 全文检索
     *
     * @param key
     * @return
     */
    @GetMapping("search")
    public List<Article> search(@RequestParam("key") String key) {
        return articleService.search(key);
    }
}

• 在启动项目之前如果程序有抛出java.lang.IllegalStateException: availableProcessors is already set to [4], rejecting [4]异常，则需要在启动类中添加：

package com.futao.springmvcdemo;

import com.alibaba.fastjson.parser.ParserConfig;
import org.mybatis.spring.annotation.MapperScan;
import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;
import org.springframework.boot.web.servlet.ServletComponentScan;
import org.springframework.cache.annotation.EnableCaching;
import org.springframework.data.elasticsearch.repository.config.EnableElasticsearchRepositories;

/**
 * @author futao
 * ServletComponentScan 开启servlet和filter
 */
@SpringBootApplication
@ServletComponentScan
@MapperScan("com.futao.springmvcdemo.dao")
@EnableCaching
//@EnableAspectJAutoProxy
@EnableElasticsearchRepositories(basePackages = "com.futao.springmvcdemo")
public class SpringmvcdemoApplication {
    public static void main(String[] args) {
        /**
         * 添加elasticsearch之后发生异常的解决方案
         * Springboot整合Elasticsearch 在项目启动前设置一下的属性，防止报错
         * 解决netty冲突后初始化client时会抛出异常
         * java.lang.IllegalStateException: availableProcessors is already set to [4], rejecting [4]
         */
        System.setProperty("es.set.netty.runtime.available.processors", "false");

        SpringApplication.run(SpringmvcdemoApplication.class, args);
        /**
         * redis反序列化
         * 开启fastjson反序列化的autoType
         */
        ParserConfig.getGlobalInstance().setAutoTypeSupport(true);
    }
}

# 测试

• 启动项目，可以在health中查看到相关的健康状况
  
• list接口请求(把数据放入elasticsearch中)
  
• 现在可以在kibana中查看到上面存入的数据
  
• 也可以进行简单的搜索测试
  
• 调用search接口测试
  

elasticsearch数据的存放位置(删除该文件夹下的数据即删除了所有的索引)

多的不说了，跟之前项目中用过的Hibernate Search很像，不过elasticsearch也是在架构层面实现的全文索引，elasticsearch可以部署在其他服务器上，减轻主服务器的压力，并通过http restful api的形式与主程序进行协调工作。elasticsearch一般通过集群方式进行部署，横向扩展非常简单，甚至只需要改几行配置就行。