Spring Boot整合MyBatis配置多数据源

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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。
使用Mybatis Plus 配置多数据源参考：Spring Boot整合MyBatis Plus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:8090spring:datasource:master:jdbc-url: jdbc:mysql://127.0.0.1:3306/test_master?characterEncoding=utf8&serverTimezone=GMT%2B8username: root
      password: root
      driver-class-name: com.mysql.cj.jdbc.Driver
    slave:jdbc-url: jdbc:mysql://127.0.0.1:3306/test_slave?characterEncoding=utf8&serverTimezone=GMT%2B8username: root
      password: root
      driver-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：

3 配置master库的源连接

@Configuration@MapperScan(basePackages ="cn.wbnull.springbootdemo.mapper.master", sqlSessionFactoryRef ="masterSqlSessionFactory")publicclassMasterDataSourceConfig{@Primary@Bean("masterDataSource")@ConfigurationProperties(prefix ="spring.datasource.master")publicDataSourcemasterDataSource(){returnDataSourceBuilder.create().build();}@Primary@Bean("masterDataSourceTransactionManager")publicDataSourceTransactionManagermasterDataSourceTransactionManager(@Qualifier("masterDataSource")DataSource dataSource){returnnewDataSourceTransactionManager(dataSource);}@Primary@Bean("masterSqlSessionFactory")publicSqlSessionFactorymasterSqlSessionFactory(@Qualifier("masterDataSource")DataSource dataSource)throwsException{SqlSessionFactoryBean sqlSessionFactory =newSqlSessionFactoryBean();
        sqlSessionFactory.setDataSource(dataSource);Resource[] resources =newPathMatchingResourcePatternResolver().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")publicclassSlaveDataSourceConfig{@Bean("slaveDataSource")@ConfigurationProperties(prefix ="spring.datasource.slave")publicDataSourceslaveDataSource(){returnDataSourceBuilder.create().build();}@Bean("slaveDataSourceTransactionManager")publicDataSourceTransactionManagerslaveDataSourceTransactionManager(@Qualifier("slaveDataSource")DataSource dataSource){returnnewDataSourceTransactionManager(dataSource);}@Bean("slaveSqlSessionFactory")publicSqlSessionFactoryslaveSqlSessionFactory(@Qualifier("slaveDataSource")DataSource dataSource)throwsException{SqlSessionFactoryBean sqlSessionFactory =newSqlSessionFactoryBean();
        sqlSessionFactory.setDataSource(dataSource);Resource[] resources =newPathMatchingResourcePatternResolver().getResources("classpath:mapper/slave/*.xml");
        sqlSessionFactory.setMapperLocations(resources);return sqlSessionFactory.getObject();}}

5 测试

5.1 新建数据库表

CREATESCHEMA`test_master`DEFAULTCHARACTERSET utf8mb4 ;CREATETABLE`test_master`.`user`(`id`INTNOTNULLAUTO_INCREMENT,`name`VARCHAR(45)NOTNULL,PRIMARYKEY(`id`));INSERTINTO`test_master`.`user`(`name`)VALUES('张三');INSERTINTO`test_master`.`user`(`name`)VALUES('李四');INSERTINTO`test_master`.`user`(`name`)VALUES('王五');INSERTINTO`test_master`.`user`(`name`)VALUES('周六');CREATESCHEMA`test_slave`DEFAULTCHARACTERSET utf8mb4 ;CREATETABLE`test_slave`.`user_info`(`id`INTNOTNULLAUTO_INCREMENT,`userCode`VARCHAR(20)NOTNULL,`userName`VARCHAR(45)NULL,`password`VARCHAR(40)NOTNULL,PRIMARYKEY(`id`));INSERTINTO`test_slave`.`user_info`(`id`,`userCode`,`userName`,`password`)VALUES('1','zhangsan','张三三','zhangsan');INSERTINTO`test_slave`.`user_info`(`id`,`userCode`,`userName`,`password`)VALUES('2','lisi','李四四','lisi');INSERTINTO`test_slave`.`user_info`(`id`,`userCode`,`userName`,`password`)VALUES('3','wangwu','王五五','wangwu');INSERTINTO`test_slave`.`user_info`(`id`,`userCode`,`userName`,`password`)VALUES('4','zhouliu','周六六','zhouliu');

5.2 新建实体类

@DatapublicclassUser{privateint id;privateString name;}

@DatapublicclassUserInfo{privateInteger id;privateString userCode;privateString userName;privateString password;}

5.3 新建Mapper

@RepositorypublicinterfaceUserMapper{voidadd(@Param("user")User user);List<User>query();voidupdate(@Param("id")int id,@Param("name")String name);voiddelete(@Param("id")int id);}

@RepositorypublicinterfaceUserInfoMapper{List<User>query();}

5.4 新建映射文件

<?xml version="1.0" encoding="UTF-8"?><!DOCTYPEmapperPUBLIC"-//mybatis.org//DTD Mapper 3.0//EN""http://mybatis.org/dtd/mybatis-3-mapper.dtd"><mappernamespace="cn.wbnull.springbootdemo.mapper.master.UserMapper"><!-- 通用查询映射结果 --><resultMapid="BaseResultMap"type="cn.wbnull.springbootdemo.entity.User"><idcolumn="id"property="id"/><resultcolumn="name"property="name"/></resultMap><!-- 通用查询结果列 --><sqlid="Base_Column_List">
        id, name
    </sql><insertid="add">
        INSERT INTO user(<includerefid="Base_Column_List"/>)
        VALUES
        (
        #{user.id},
        #{user.name}
        )
    </insert><selectid="query"resultMap="BaseResultMap">
        SELECT * FROM user
    </select><updateid="update">
        UPDATE user SET name = '${name}' WHERE id = '${id}'
    </update><updateid="delete">
        DELETE FROM user where id = '${id}'
    </update></mapper>

<?xml version="1.0" encoding="UTF-8"?><!DOCTYPEmapperPUBLIC"-//mybatis.org//DTD Mapper 3.0//EN""http://mybatis.org/dtd/mybatis-3-mapper.dtd"><mappernamespace="cn.wbnull.springbootdemo.mapper.slave.UserInfoMapper"><!-- 通用查询映射结果 --><resultMapid="BaseResultMap"type="cn.wbnull.springbootdemo.entity.UserInfo"><idcolumn="id"property="id"/><resultcolumn="userCode"property="userCode"/><resultcolumn="userName"property="userName"/><resultcolumn="password"property="password"/></resultMap><!-- 通用查询结果列 --><sqlid="Base_Column_List">
        id, userCode, userName, password
    </sql><selectid="query"resultMap="BaseResultMap">
        SELECT * FROM user_info
    </select></mapper>

5.5 新建Service

@ServicepublicclassUserService{@AutowiredprivateUserMapper userMapper;publicStringadd(String name){User user =newUser();
        user.setName(name);

        userMapper.add(user);return"操作成功";}publicList<User>query(){return userMapper.query();}publicStringupdate(int id,String name){
        userMapper.update(id, name);return"操作成功";}publicStringdelete(int id){
        userMapper.delete(id);return"操作成功";}}

@ServicepublicclassUserInfoService{@AutowiredprivateUserInfoMapper userInfoMapper;publicList<User>query(){return userInfoMapper.query();}}

5.6 新建Controller

@RestController@RequestMapping("user")publicclassUserController{@AutowiredpublicUserService userService;@PostMapping(value ="add")publicStringadd(@RequestParam(value ="name")String name){return userService.add(name);}@PostMapping(value ="query")publicList<User>query(){return userService.query();}@PostMapping(value ="update")publicStringupdate(@RequestParam(value ="id")int id,@RequestParam(value ="name")String name){return userService.update(id, name);}@PostMapping(value ="delete")publicStringdelete(@RequestParam(value ="id")int id){return userService.delete(id);}}

@Controller@RequestMapping("userInfo")publicclassUserInfoController{@AutowiredpublicUserInfoService userInfoService;@PostMapping(value ="query")publicList<User>query(){return userInfoService.query();}}

5.7 测试

使用Postman测试，输出结果如下

5.8.1 master select

5.8.2 master insert

数据库中插入成功

5.8.3 master update

数据库中更新成功

5.8.4 master delete

数据库中删除成功

5.8.5 slave select

截至这里，Spring Boot已经成功整合MyBatis多数据源，并连接上了数据库，且测试正常。