Spring Boot整合Mybatis配置多数据源

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

多数据源即动态数据源，随着项目开发逐渐扩大，单个数据源、单一数据源已经无法满足需求项目的支撑需求。

或是单一数据库无法承载大数据量的访问，需使用多个数据库进行数据的读写分离；

或是某些特殊业务需求，需操作不同的数据库。

在 Spring Boot整合MyBatis连接数据库文章中，展示了Spring Boot整合MyBatis连接数据库的方法，基于此，Spring Boot 整合MyBatis 配置多数据源。

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>org.mybatis.spring.boot</groupId><artifactId>mybatis-spring-boot-starter</artifactId><version>1.3.2</version>
</dependency>
<dependency><groupId>mysql</groupId><artifactId>mysql-connector-java</artifactId><version>8.0.28</version><scope>runtime</scope>
</dependency><!--lombok-->
<dependency><groupId>org.projectlombok</groupId><artifactId>lombok</artifactId><version>1.18.30</version><scope>provided</scope>
</dependency>

2 引入数据源

server:port: 8090
spring:datasource:master:jdbc-url: jdbc:mysql://127.0.0.1:3306/test_master?characterEncoding=utf8&serverTimezone=GMT%2B8username: rootpassword: rootdriver-class-name: com.mysql.cj.jdbc.Driverslave:jdbc-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:mapper-locations: classpath:mapper/**/*.xmltype-aliases-package: cn.wbnull.springbootdemo.entity

该配置方式下，需要操作的两个数据库的Mapper需放置在不同文件夹下，如下图所示：
在这里插入图片描述

3 配置master库的源连接

@Configuration
@MapperScan(basePackages = "cn.wbnull.springbootdemo.mapper.master", sqlSessionFactoryRef = "masterSqlSessionFactory")
public class MasterDataSourceConfig {@Primary@Bean("masterDataSource")@ConfigurationProperties(prefix = "spring.datasource.master")public DataSource masterDataSource() {return DataSourceBuilder.create().build();}@Primary@Bean("masterDataSourceTransactionManager")public DataSourceTransactionManager masterDataSourceTransactionManager(@Qualifier("masterDataSource") DataSource dataSource) {return new DataSourceTransactionManager(dataSource);}@Primary@Bean("masterSqlSessionFactory")public SqlSessionFactory masterSqlSessionFactory(@Qualifier("masterDataSource") DataSource dataSource) throws Exception {SqlSessionFactoryBean sqlSessionFactory = new SqlSessionFactoryBean();sqlSessionFactory.setDataSource(dataSource);Resource[] resources = new PathMatchingResourcePatternResolver().getResources("classpath:mapper/master/*.xml");sqlSessionFactory.setMapperLocations(resources);return sqlSessionFactory.getObject();}
}

4 配置slave库的源连接

@Configuration
@MapperScan(basePackages = "cn.wbnull.springbootdemo.mapper.slave", sqlSessionFactoryRef = "slaveSqlSessionFactory")
public class SlaveDataSourceConfig {@Bean("slaveDataSource")@ConfigurationProperties(prefix = "spring.datasource.slave")public DataSource slaveDataSource() {return DataSourceBuilder.create().build();}@Bean("slaveDataSourceTransactionManager")public DataSourceTransactionManager slaveDataSourceTransactionManager(@Qualifier("slaveDataSource") DataSource dataSource) {return new DataSourceTransactionManager(dataSource);}@Bean("slaveSqlSessionFactory")public SqlSessionFactory slaveSqlSessionFactory(@Qualifier("slaveDataSource") DataSource dataSource) throws Exception {SqlSessionFactoryBean sqlSessionFactory = new SqlSessionFactoryBean();sqlSessionFactory.setDataSource(dataSource);Resource[] resources = new PathMatchingResourcePatternResolver().getResources("classpath:mapper/slave/*.xml");sqlSessionFactory.setMapperLocations(resources);return sqlSessionFactory.getObject();}
}

5 测试

5.1 新建数据库表

CREATE SCHEMA `test_master` DEFAULT CHARACTER SET utf8mb4 ;CREATE TABLE `test_master`.`user` (`id` INT NOT NULL AUTO_INCREMENT,`name` VARCHAR(45) NOT NULL,PRIMARY KEY (`id`));INSERT INTO `test_master`.`user` (`name`) VALUES ('张三');
INSERT INTO `test_master`.`user` (`name`) VALUES ('李四');
INSERT INTO `test_master`.`user` (`name`) VALUES ('王五');
INSERT INTO `test_master`.`user` (`name`) VALUES ('周六');CREATE SCHEMA `test_slave` DEFAULT CHARACTER SET utf8mb4 ;CREATE TABLE `test_slave`.`user_info` (`id` INT NOT NULL AUTO_INCREMENT,`userCode` VARCHAR(20) NOT NULL,`userName` VARCHAR(45) NULL,`password` VARCHAR(40) NOT NULL,PRIMARY KEY (`id`));INSERT INTO `test_slave`.`user_info` (`id`, `userCode`, `userName`, `password`) VALUES ('1', 'zhangsan', '张三三', 'zhangsan');
INSERT INTO `test_slave`.`user_info` (`id`, `userCode`, `userName`, `password`) VALUES ('2', 'lisi', '李四四', 'lisi');
INSERT INTO `test_slave`.`user_info` (`id`, `userCode`, `userName`, `password`) VALUES ('3', 'wangwu', '王五五', 'wangwu');
INSERT INTO `test_slave`.`user_info` (`id`, `userCode`, `userName`, `password`) VALUES ('4', 'zhouliu', '周六六', 'zhouliu');

5.2 新建实体类

@Data
public class User {private int id;private String name;
}

@Data
public class UserInfo {private Integer id;private String userCode;private String userName;private String password;
}

5.3 新建Mapper

@Repository
public interface UserMapper {void add(@Param("user") User user);List<User> query();void update(@Param("id") int id, @Param("name") String name);void delete(@Param("id") int id);
}

@Repository
public interface UserInfoMapper {List<User> query();
}

5.4 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.master.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><insert id="add">INSERT INTO user(<include refid="Base_Column_List"/>)VALUES(#{user.id},#{user.name})</insert><select id="query" resultMap="BaseResultMap">SELECT * FROM user</select><update id="update">UPDATE user SET name = '${name}' WHERE id = '${id}'</update><update id="delete">DELETE FROM user where id = '${id}'</update>
</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.slave.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><select id="query" resultMap="BaseResultMap">SELECT * FROM user_info</select>
</mapper>

5.5 新建Service

@Service
public class UserService {@Autowiredprivate UserMapper userMapper;public String add(String name) {User user = new User();user.setName(name);userMapper.add(user);return "操作成功";}public List<User> query() {return userMapper.query();}public String update(int id, String name) {userMapper.update(id, name);return "操作成功";}public String delete(int id) {userMapper.delete(id);return "操作成功";}
}

@Service
public class UserInfoService {@Autowiredprivate UserInfoMapper userInfoMapper;public List<User> query() {return userInfoMapper.query();}
}

5.6 新建Controller

@RestController
@RequestMapping("user")
public class UserController {@Autowiredpublic UserService userService;@PostMapping(value = "add")public String add(@RequestParam(value = "name") String name) {return userService.add(name);}@PostMapping(value = "query")public List<User> query() {return userService.query();}@PostMapping(value = "update")public String update(@RequestParam(value = "id") int id, @RequestParam(value = "name") String name) {return userService.update(id, name);}@PostMapping(value = "delete")public String delete(@RequestParam(value = "id") int id) {return userService.delete(id);}
}

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