springboot中elasticsearch的集成与使用

矫情吗；* 2022-03-17 01:48 200阅读 0赞

[个人博客][Link 1]

Elasticsearch是一个开源、分布式、RESTful搜索和分析引擎。 Spring Boot为Elasticsearch提供基本的自动配置。

springboot支持多个http客户端：Java的“Low Level”（RestClient）and “High Level”（RestHighLevelClient）的rest客户端，以及Jest。同时，传输客户端也仍在Spring Data Elasticsearch中使用。

下面就来介绍一下spring boot如何通过 spring data使用elasticsearch。

> [如何安装elasticsearch？][elasticsearch]

## 引入依赖 ##

首先是引入 Spring Data Elasticsearch的依赖，同时为了通过web接口断来测试，亦加入web的依赖。

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

## es环境配置 ##

在application.yml文件中写入es的配置，这里是以三个节点为例（需要说明的是，es默认的集群名字为elasticsearch，且一个节点也是集群）。

spring:
      data:
        elasticsearch:
          cluster-name: elasticsearch-cluster
          cluster-nodes: 127.0.0.1:9300,127.0.0.1:9301,177.0.0.1:9302

## 应用案例 ##

这里通过一个简单的案例代码来介绍：用户信息的添加和查询。

### 实体PO ###

在po上，以@Document注解来标明存入的索引以及类型：

package com.lazycece.sbac.elasticsearch.entity;
    
    import lombok.AllArgsConstructor;
    import lombok.Builder;
    import lombok.Data;
    import lombok.NoArgsConstructor;
    import org.springframework.data.elasticsearch.annotations.Document;
    
    import java.util.Date;
    
    /** * @author lazycece * @date 2018/10/16 */
    @Data
    @Builder
    @AllArgsConstructor
    @NoArgsConstructor
    @Document(indexName = "index", type = "doc")
    public class User { 
    
        private String id;
        private String username;
        private String name;
        private Integer age;
        private Date createTime = new Date();
        private Date updateTime = new Date();
    }

### po层代码 ###

这里在po层用repository的形式进行交互，当然也可以选取用template形式交互。

package com.lazycece.sbac.elasticsearch.repository;
    
    import com.lazycece.sbac.elasticsearch.entity.User;
    import org.springframework.data.elasticsearch.repository.ElasticsearchRepository;
    
    /** * @author lazycece * @date 2018/10/16 */
    public interface UserEsRepository extends ElasticsearchRepository<User,String> { 
        User findByUsername(String name);
    }

### 接口层代码 ###

这里通过简单的两个接口来应用es的查询和写入操作：

package com.lazycece.sbac.elasticsearch.controller;
    
    import com.lazycece.sbac.elasticsearch.entity.User;
    import com.lazycece.sbac.elasticsearch.repository.UserEsRepository;
    import org.springframework.beans.factory.annotation.Autowired;
    import org.springframework.util.StringUtils;
    import org.springframework.web.bind.annotation.*;
    
    /** * @author lazycece * @date 2018/10/16 */
    @RestController
    @RequestMapping("/elasticsearch")
    public class ElasticsearchDemoController { 
    
        private UserEsRepository userEsRepository;
    
        @Autowired
        public ElasticsearchDemoController(UserEsRepository userEsRepository) { 
            this.userEsRepository = userEsRepository;
        }
    
        @GetMapping("/demo")
        public Object demo() { 
            return "welcome to elasticsearch cluster demo ...";
        }
    
        @PutMapping("/user/add")
        public Object addUserInfo(User user) { 
            if (StringUtils.isEmpty(user.getName().trim())) { 
                return "add user fail: username is null ...";
            }
            User userFind = userEsRepository.findByUsername(user.getUsername());
            if (userFind != null) { 
                return "add user fail: user exist";
            }
            userEsRepository.save(user);
            return "add user success ...";
        }
    
        @GetMapping("/user/info")
        public Object getUserInfo(@RequestParam String username) { 
            return userEsRepository.findByUsername(username);
        }
    }

### 单元测试验证 ###

package com.lazycece.sbac.elasticsearch.controller;
    
    import org.junit.Test;
    import org.junit.runner.RunWith;
    import org.springframework.boot.test.autoconfigure.web.servlet.AutoConfigureMockMvc;
    import org.springframework.boot.test.context.SpringBootTest;
    import org.springframework.test.context.junit4.SpringRunner;
    import org.springframework.test.web.servlet.MockMvc;
    import org.springframework.test.web.servlet.request.MockMvcRequestBuilders;
    import org.springframework.test.web.servlet.result.MockMvcResultHandlers;
    import org.springframework.test.web.servlet.result.MockMvcResultMatchers;
    import org.springframework.util.LinkedMultiValueMap;
    import org.springframework.util.MultiValueMap;
    
    import javax.annotation.Resource;
    
    @RunWith(SpringRunner.class)
    @SpringBootTest(webEnvironment = SpringBootTest.WebEnvironment.RANDOM_PORT)
    @AutoConfigureMockMvc
    public class ElasticsearchDemoControllerTest { 
    
        @Resource
        private MockMvc mockMvc;
    
    
        @Test
        public void testAddUserInfo() throws Exception { 
            MultiValueMap<String, String> params = new LinkedMultiValueMap<>();
            params.add("username", "lazycece");
            params.add("name", "W");
            params.add("age", "99");
            this.mockMvc.perform(
                    MockMvcRequestBuilders
                            .put("/elasticsearch/user/add")
                            .params(params))
                    .andExpect(MockMvcResultMatchers.status().isOk())
                    .andDo(MockMvcResultHandlers.print());
        }
    
        @Test
        public void testGetUserInfo() throws Exception { 
            this.mockMvc.perform(
                    MockMvcRequestBuilders
                            .get("/elasticsearch/user/info")
                            .param("username", "lazycece"))
                    .andExpect(MockMvcResultMatchers.status().isOk())
                    .andDo(MockMvcResultHandlers.print());
        }
    }

## 案例源码 ##

案例源码地址：[https://github.com/lazycece/springboot-actual-combat/tree/master/springboot-ac-elasticsearch][https_github.com_lazycece_springboot-actual-combat_tree_master_springboot-ac-elasticsearch]

[Link 1]: https://lazycece.github.io/2019/02/21/springboot%E4%B8%ADelasticsearch%E7%9A%84%E9%9B%86%E6%88%90%E4%B8%8E%E4%BD%BF%E7%94%A8/
[elasticsearch]: https://lazycece.github.io/2019/01/30/ubuntu%E4%B8%8B%E5%AE%89%E8%A3%85elasticsearch/
[https_github.com_lazycece_springboot-actual-combat_tree_master_springboot-ac-elasticsearch]: https://github.com/lazycece/springboot-actual-combat/tree/master/springboot-ac-elasticsearch