微服务Mybatis连接Mysql数据库

在class-common模块中，添加实体类，对应mysql中的表：

//使用lombok生成getset

@Data
public class User {
	private Integer id;
	private String name;
	private String pwd;
	private String headImg;
	private String phone;
	private Date createTime;
	private String wechat;
}

@Data
public class Video {
	private Integer id;
	private String title;
	private String summary;
	private String coverImg;
	private Integer  price;
	private Date createTime;
	private Double point;
}

@Data
public class VideoOrder {
	private Integer id;
	private String outTradeNo;
	private Integer state;
	private Date createTime;
	private  Integer totalFee;
	private Integer videoId;
	private String videoTitle;
	private String videoImg;
	private Integer userId;
}

Mybatis依赖导入 + 数据库配置

在父项目的POM中添加Mybatis依赖：

<!-- Mybatis -->
<dependency>
    <groupId>org.mybatis.spring.boot</groupId>
    <artifactId>mybatis-spring-boot-starter</artifactId>
    <version>2.1.2</version>
    <type>pom</type>
    <scope>import</scope>
</dependency>

在video、user、order模块中的POM添加Mybatis和Mysql驱动依赖：

//3个服务的POM都需要添加

<dependency>
    <groupId>org.mybatis.spring.boot</groupId>
    <artifactId>mybatis-spring-boot-starter</artifactId>
</dependency>
<dependency>
    <groupId>mysql</groupId>
    <artifactId>mysql-connector-java</artifactId>
</dependency>

3个模块配置数据库连接（记得修改端口、应用名称、数据库名称）

//3个服务分别添加，在resources目录下新建application.yml文件，添加如下内容，每个服务连接的数据库记得更改

server:
  port: 9000  # 服务端口，每个服务记得更改，确保未被占用
spring:
  application:
    name: class-video-service   # 服务名称，每个服务名记得更改，不能一样
  datasource:
    driver-class-name: com.mysql.cj.jdbc.Driver
    url: jdbc:mysql://127.0.0.1:3306/cloud_video?useUnicode=true&characterEncoding=utf-8&useSSL=false
    username: root
    password: 123456
# 控制台输出sql、下划线转驼峰
mybatis:
  configuration:
    log-impl: org.apache.ibatis.logging.stdout.StdOutImpl
    map-underscore-to-camel-case: true

测试数据库连接

以视频模块video为例，添加启动类：

import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;

@SpringBootApplication
public class VideoApplication {
    public static void main(String[] args) {
        SpringApplication.run(VideoApplication.class, args);
    }
}

controller->service->mapper 开发：

VideoController.java

import com.study.service.VideoService;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.web.bind.annotation.GetMapping;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RestController;

@RestController
@RequestMapping("/api/v1/video")
public class VideoController {
    @Autowired
    private VideoService videoService;

    //根据ID查询视频
    @GetMapping("/find_by_id")
    public Object findById(int videoId){
        return videoService.findById(videoId);
    }
}

VideoMapper.java

import com.study.pojo.Video;
import org.apache.ibatis.annotations.Mapper;
import org.apache.ibatis.annotations.Select;

//此处注意@Repository和@Mapper的区别，使用@Mapper注解，不需要在启动类上加入@MapperScan注解，如果使用@Repository注解，则需要在启动类上加入@MapperScan注解
@Mapper
public interface VideoMapper {
    //根据ID查询视频
    @Select("select * from video where id = #{videoId}")
    Video findById(int videoId);
}

VideoService.java

import com.study.pojo.Video;

public interface VideoService {
    //根据ID查询视频
    Video findById(int videoId);
}

VideoServiceImpl.java

import com.study.mapper.VideoMapper;
import com.study.pojo.Video;
import com.study.service.VideoService;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Service;

@Service
public class VideoServiceImpl implements VideoService {
    @Autowired
    private VideoMapper videoMapper;

    //根据ID查询视频
    @Override
    public Video findById(int videoId) {
        return videoMapper.findById(videoId);
    }
}

启动后访问测试

http://127.0.0.1:9000/api/v1/video/find_by_id?videoId=