一、安装Elasticsearch

1、Windows安装

Windows安装比较简单，ES官网Download Elasticsearch | Elastic下载压缩包，解压出来， bin 目录下有个elasticsearch.bat，双击，就运行起来了。

然后在浏览器输入localhost:9200验证，成功会返回下面的图片。

二、开始写代码

我的springboot版本是2.7.5，ES是7.17.3

官方文档
项目结构如下：

1、引入依赖

<!-- spring data es -->
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-data-elasticsearch</artifactId>
        </dependency>
        <!-- https://mvnrepository.com/artifact/jakarta.json/jakarta.json-api -->
        <dependency>
            <groupId>jakarta.json</groupId>
            <artifactId>jakarta.json-api</artifactId>
            <version>2.0.1</version>
        </dependency>

2、配置文件

两种方式
（1）yaml配置文件

server:
  port: 8081
spring:
  elasticsearch:
    # elasticsearch地址
    uris: localhost:9200
    connection-timeout: 30000
    socket-timeout: 50000
    socket-keep-alive: false

（2）api 方式

会覆盖掉yml

import co.elastic.clients.elasticsearch.ElasticsearchClient;
import co.elastic.clients.json.jackson.JacksonJsonpMapper;
import co.elastic.clients.transport.ElasticsearchTransport;
import co.elastic.clients.transport.rest_client.RestClientTransport;
import org.apache.http.HttpHost;
import org.elasticsearch.client.RestClient;
import org.springframework.boot.SpringBootConfiguration;
import org.springframework.context.annotation.Bean;

/**
 * @author 
 */
@SpringBootConfiguration
public class ElasticSearchConfig {
    @Bean
    public ElasticsearchClient elasticsearchClient(){
        RestClient client = RestClient.builder(new HttpHost("localhost", 9200))
                .setRequestConfigCallback(requestConfigBuilder -> requestConfigBuilder
                        .setConnectTimeout(30000)
                        .setSocketTimeout(50000))
                .build();
        ElasticsearchTransport transport = new RestClientTransport(client, new JacksonJsonpMapper());
        return new ElasticsearchClient(transport);
    }

}

3、新建 User 实体类

id这个字段一定要有，作为主键索引，这个@Document里面的indexName就相当于mysql里面的表名，在elasticsearch里面叫索引。

import lombok.AllArgsConstructor;
import lombok.Data;
import lombok.NoArgsConstructor;
import org.springframework.data.annotation.Id;
import org.springframework.data.elasticsearch.annotations.Document;

@Data
@AllArgsConstructor
@NoArgsConstructor
@Document(indexName = "user")
public class User {
    @Id
    private String id;
    private String name;
    private String sex;
    private Integer age;
}

4、新建 UserRepository

import com.example.demo.document.User;
import org.springframework.data.elasticsearch.repository.ElasticsearchRepository;

/**
 * @author 
 */
public interface UserRepository extends ElasticsearchRepository<User, String> {
}

5、新建 Controller

import com.example.demo.document.User;
import com.example.demo.repository.UserRepository;
import org.springframework.data.domain.Page;
import org.springframework.data.domain.PageRequest;
import org.springframework.data.domain.Pageable;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RestController;

@RestController
@RequestMapping("/user")
public class UserController {
    private final UserRepository userRepository;

    public UserController(UserRepository userRepository){
        this.userRepository = userRepository;
    }

    /**
     * 添加
     */
    @RequestMapping("/insert")
    public String insert() {
        User user = new User();
        user.setId("1");
        user.setName("徐一杰");
        user.setSex("男");
        user.setAge(22);
        userRepository.save(user);
        return "success";
    }

    /**
     * 删除
     */
    @RequestMapping("/delete")
    public String delete() {
        User user = userRepository.findById("1").get();
        userRepository.delete(user);
        return "success";
    }

    /**
     * 局部更新
     */
    @RequestMapping("/update")
    public String update() {
        User user = userRepository.findById("1").get();
        user.setName("泡泡");
        userRepository.save(user);
        return "success";
    }
    /**
     * 查询
     */
    @RequestMapping("/get")
    public User get() {
        User user = userRepository.findById("1").get();
        System.out.println(user);
        return user;
    }

    @RequestMapping("/getAll")
    public Page<User> getAll() {
        Pageable pageable = PageRequest.of(1,20);
        Page<User> user = userRepository.findAll(pageable);
        System.out.println(user);
        return user;
    }
}

6、测试

(1) 启动项目

可以看到，我们的user索引自动添加到elasticsearch里面了。

(2) 查询索引

我们用postman请求 http://localhost:8081/user/getAll，可以看到，返回了 user 的信息。