Spring Boot整合MyBatis Plus配置多数据源-编程知识

Spring Boot 专栏：https://blog.csdn.net/dkbnull/category_9278145.html
Spring Cloud 专栏：https://blog.csdn.net/dkbnull/category_9287932.html
GitHub：https://github.com/dkbnull/SpringBootDemo
Gitee：https://gitee.com/dkbnull/SpringBootDemo

在 Spring Boot整合MyBatis配置多数据源文章中，展示了Spring Boot整合Mybatis配置多数据源的方法。那么，如果使用MyBatis Plus，如何配置多数据源呢？

官方文档：https://baomidou.com/pages/a61e1b/

MyBatis Plus连接数据库参考：Spring Boot整合MyBatis Plus连接数据库

0 开发环境

JDK：1.8
Spring Boot：2.1.1.RELEASE
MySQL：5.7.13

1 引入依赖

<dependency><groupId>com.baomidou</groupId><artifactId>mybatis-plus-boot-starter</artifactId><version>3.5.4</version>
</dependency>
<dependency><groupId>mysql</groupId><artifactId>mysql-connector-java</artifactId><scope>runtime</scope>
</dependency><dependency><groupId>com.baomidou</groupId><artifactId>dynamic-datasource-spring-boot-starter</artifactId><version>3.5.2</version>
</dependency><dependency><groupId>org.projectlombok</groupId><artifactId>lombok</artifactId><version>1.18.30</version><scope>provided</scope>
</dependency>

2 配置数据源

server:port: 8090
spring:datasource:dynamic:primary: master       #设置默认的数据源或者数据源组，默认值即为masterstrict: false         #严格匹配数据源，默认false。true未匹配到指定数据源时抛异常，false使用默认数据源datasource:master:url: jdbc:mysql://127.0.0.1:3306/test_master?characterEncoding=utf8&serverTimezone=GMT%2B8username: rootpassword: rootdriver-class-name: com.mysql.cj.jdbc.Driver     #3.2.0开始支持SPI可省略此配置slave:url: jdbc:mysql://127.0.0.1:3306/test_slave?characterEncoding=utf8&serverTimezone=GMT%2B8username: rootpassword: rootdriver-class-name: com.mysql.cj.jdbc.Driver
#
mybatis-plus:mapper-locations: classpath:mapper/*.xmltype-aliases-package: cn.wbnull.springbootdemo.entity

3 使用@DS切换数据源

@DS 可以注解在方法上或类上，同时存在就近原则方法上注解优先于类上注解。

注解	结果
没有@DS	默认数据源
@DS(“dsName”)	dsName可以为组名也可以为具体某个库的名称

@DS("slave")
@Service
public class UserInfoService {@Autowiredprivate UserInfoMapper userInfoMapper;public List<UserInfo> query() {LambdaQueryWrapper<UserInfo> queryWrapper = new LambdaQueryWrapper<>();return userInfoMapper.selectList(queryWrapper);}
}

4 测试

直接使用 Spring Boot整合MyBatis配置多数据源中创建的数据库表

4.1 新建实体类

@Data
public class User implements Serializable {private static final long serialVersionUID = 1L;@TableId(value = "id", type = IdType.AUTO)private int id;private String name;
}

@Data
public class UserInfo implements Serializable {private static final long serialVersionUID = 1L;@TableId(value = "id", type = IdType.AUTO)private Integer id;@TableField("userCode")private String userCode;@TableField("userName")private String userName;private String password;
}

注：这里因为数据库里字段是驼峰式命名，所以使用 @TableField 指定对应的数据库字段名，也可以通过yml配置关闭属性映射

mybatis-plus:mapper-locations: classpath:mapper/*.xmltype-aliases-package: cn.wbnull.springbootdemo.entityconfiguration:map-underscore-to-camel-case: false

4.2 新建Mapper

@Repository
public interface UserMapper extends BaseMapper<User> {}

@Repository
public interface UserInfoMapper extends BaseMapper<UserInfo> {}

4.3 新建映射文件

<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE mapper PUBLIC "-//mybatis.org//DTD Mapper 3.0//EN" "http://mybatis.org/dtd/mybatis-3-mapper.dtd">
<mapper namespace="cn.wbnull.springbootdemo.mapper.UserMapper"><!-- 通用查询映射结果 --><resultMap id="BaseResultMap" type="cn.wbnull.springbootdemo.entity.User"><id column="id" property="id"/><result column="name" property="name"/></resultMap><!-- 通用查询结果列 --><sql id="Base_Column_List">id, name</sql>
</mapper>

<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE mapper PUBLIC "-//mybatis.org//DTD Mapper 3.0//EN" "http://mybatis.org/dtd/mybatis-3-mapper.dtd">
<mapper namespace="cn.wbnull.springbootdemo.mapper.UserInfoMapper"><!-- 通用查询映射结果 --><resultMap id="BaseResultMap" type="cn.wbnull.springbootdemo.entity.UserInfo"><id column="id" property="id"/><result column="userCode" property="userCode"/><result column="userName" property="userName"/><result column="password" property="password"/></resultMap><!-- 通用查询结果列 --><sql id="Base_Column_List">id, userCode, userName, password</sql></mapper>

4.4 新建Service

@Service
public class UserService {@Autowiredprivate UserMapper userMapper;public List<User> query() {LambdaQueryWrapper<User> queryWrapper = new LambdaQueryWrapper<>();return userMapper.selectList(queryWrapper);}
}

/*** 3使用@DS切换数据源 中已展示过该类*/
@DS("slave")
@Service
public class UserInfoService {@Autowiredprivate UserInfoMapper userInfoMapper;public List<UserInfo> query() {LambdaQueryWrapper<UserInfo> queryWrapper = new LambdaQueryWrapper<>();return userInfoMapper.selectList(queryWrapper);}
}

4.5 新建Controller

@RestController
@RequestMapping("user")
public class UserController {@Autowiredpublic UserService userService;@PostMapping(value = "query")public List<User> query() {return userService.query();}
}

@RestController
@RequestMapping("userInfo")
public class UserInfoController {@Autowiredpublic UserInfoService userInfoService;@PostMapping(value = "query")public List<UserInfo> query() {return userInfoService.query();}
}