前言
MyBatis 多数据源配置，最近在项目建设中，需要在原有系统上扩展一个新的业务模块，特意将数据库分库，以便减少复杂度。本文直接以简单的代码示例，如何对 MyBatis 多数据源配置。
准备
创建数据库
db_test
SET NAMES utf8mb4;
SET FOREIGN_KEY_CHECKS = 0;
-- ----------------------------
-- Table structure for t_user
-- ----------------------------
DROP TABLE IF EXISTS `t_user`;
CREATE TABLE `t_user` (
`id` int(8) NOT NULL AUTO_INCREMENT COMMENT 'ID',
`user_name` varchar(20) CHARACTER SET utf8 COLLATE utf8_general_ci DEFAULT NULL COMMENT '用户姓名',
`user_sex` char(1) CHARACTER SET utf8 COLLATE utf8_general_ci DEFAULT NULL COMMENT '用户性别',
PRIMARY KEY (`id`)
) ENGINE=InnoDB AUTO_INCREMENT=23 DEFAULT CHARSET=utf8;
-- ----------------------------
-- Records of t_user
-- ----------------------------
BEGIN;
INSERT INTO `t_user` VALUES (1, '刘备', '男');
INSERT INTO `t_user` VALUES (2, '孙尚香', '女');
INSERT INTO `t_user` VALUES (3, '周瑜', '男');
INSERT INTO `t_user` VALUES (4, '小乔', '女');
INSERT INTO `t_user` VALUES (5, '诸葛亮', '男');
INSERT INTO `t_user` VALUES (6, '黄月英', '女');
INSERT INTO `t_user` VALUES (7, '关羽', '男');
INSERT INTO `t_user` VALUES (8, '张飞', '男');
INSERT INTO `t_user` VALUES (9, '赵云', '男');
INSERT INTO `t_user` VALUES (10, '黄总', '男');
INSERT INTO `t_user` VALUES (11, '曹操', '男');
INSERT INTO `t_user` VALUES (12, '司马懿', '男');
INSERT INTO `t_user` VALUES (13, '貂蝉', '女');
INSERT INTO `t_user` VALUES (14, '吕布', '男');
INSERT INTO `t_user` VALUES (15, '马超', '男');
INSERT INTO `t_user` VALUES (16, '魏延', '男');
INSERT INTO `t_user` VALUES (17, '孟获', '男');
INSERT INTO `t_user` VALUES (18, '大乔', '女');
INSERT INTO `t_user` VALUES (19, '刘婵', '男');
INSERT INTO `t_user` VALUES (20, '姜维', '男');
INSERT INTO `t_user` VALUES (21, '廖化', '男');
INSERT INTO `t_user` VALUES (22, '关平', '男');
COMMIT;
SET FOREIGN_KEY_CHECKS = 1;
dbb_test2
SET NAMES utf8mb4;
SET FOREIGN_KEY_CHECKS = 0;
-- ----------------------------
-- Table structure for t_hero
-- ----------------------------
DROP TABLE IF EXISTS `t_hero`;
CREATE TABLE `t_hero` (
`id` int(11) NOT NULL AUTO_INCREMENT COMMENT 'ID',
`hero_code` varchar(32) DEFAULT NULL COMMENT '英雄编码',
`hero_name` varchar(20) DEFAULT NULL COMMENT '英雄名称',
PRIMARY KEY (`id`)
) ENGINE=InnoDB AUTO_INCREMENT=2 DEFAULT CHARSET=utf8;
-- ----------------------------
-- Records of t_hero
-- ----------------------------
BEGIN;
INSERT INTO `t_hero` VALUES (1, '001', '德玛西亚');
COMMIT;
SET FOREIGN_KEY_CHECKS = 1;
构建项目，项目目录结构
pom 文件
<?xml version="1.0" encoding="UTF-8"?>
<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 https://maven.apache.org/xsd/maven-4.0.0.xsd">
<modelVersion>4.0.0</modelVersion>
<parent>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-parent</artifactId>
<version>2.1.9.RELEASE</version>
<relativePath/> <!-- lookup parent from repository -->
</parent>
<groupId>cn.zwqh</groupId>
<artifactId>spring-boot-mybatis-mulidatasource</artifactId>
<version>0.0.1-SNAPSHOT</version>
<name>spring-boot-mybatis-mulidatasource</name>
<description>spring-boot-mybatis-mulidatasource</description>
<properties>
<java.version>1.8</java.version>
</properties>
<dependencies>
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-web</artifactId>
</dependency>
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-test</artifactId>
<scope>test</scope>
</dependency>
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-jdbc</artifactId>
</dependency>
<!-- 热部署模块 -->
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-devtools</artifactId>
<optional>true</optional> <!-- 这个需要为 true 热部署才有效 -->
</dependency>
<!-- mysql 数据库驱动. -->
<dependency>
<groupId>mysql</groupId>
<artifactId>mysql-connector-java</artifactId>
<scope>runtime</scope>
</dependency>
<!-- mybaits -->
<dependency>
<groupId>org.mybatis.spring.boot</groupId>
<artifactId>mybatis-spring-boot-starter</artifactId>
<version>2.1.0</version>
</dependency>
<!-- alibaba的druid数据库连接池 -->
<dependency>
<groupId>com.alibaba</groupId>
<artifactId>druid-spring-boot-starter</artifactId>
<version>1.1.20</version>
</dependency>
<!-- pagehelper -->
<dependency>
<groupId>com.github.pagehelper</groupId>
<artifactId>pagehelper-spring-boot-starter</artifactId>
<version>1.2.12</version>
</dependency>
</dependencies>
<build>
<plugins>
<plugin>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-maven-plugin</artifactId>
</plugin>
</plugins>
</build>
</project>
这里使用了alibaba的druid数据库连接池，Druid 能够提供强大的监控和扩展功能。这里我们暂时只做简单的应用。
配置文件
#master 数据源配置
master.datasource.driver-class-name=com.mysql.cj.jdbc.Driver
master.datasource.url=jdbc:mysql://127.0.0.1:3306/db_test?useUnicode=true&characterEncoding=UTF-8&useSSL=true
master.datasource.username=root
master.datasource.password=zwqh@0258
#slave 数据源配置
slave.datasource.driver-class-name=com.mysql.cj.jdbc.Driver
slave.datasource.url=jdbc:mysql://127.0.0.1:3306/db_test2?useUnicode=true&characterEncoding=UTF-8&useSSL=true
slave.datasource.username=root
slave.datasource.password=zwqh@0258
#mybatis
mybatis.mapper-locations=classpath:/mapper/**/*Mapper.xml
数据源配置
MasterDataSourceConfig 对应数据库 db_test
@Configuration
@MapperScan(basePackages = "cn.zwqh.springboot.dao.master", sqlSessionFactoryRef = "masterSqlSessionFactory")
public class MasterDataSourceConfig {
@Value("${master.datasource.driver-class-name}")
private String driverClassName;
@Value("${master.datasource.url}")
private String url;
@Value("${master.datasource.username}")
private String username;
@Value("${master.datasource.password}")
private String password;
@Bean(name = "masterDataSource")
@Primary
public DataSource dataSource() {
DruidDataSource dataSource = new DruidDataSource();
dataSource.setDriverClassName(this.driverClassName);
dataSource.setUrl(this.url);
dataSource.setUsername(this.username);
dataSource.setPassword(this.password);
return dataSource;
}
@Bean(name = "masterSqlSessionFactory")
@Primary
public SqlSessionFactory sqlSessionFactory(@Qualifier("masterDataSource") DataSource dataSource) throws Exception {
SqlSessionFactoryBean bean = new SqlSessionFactoryBean();
bean.setDataSource(dataSource);
bean.setMapperLocations(
new PathMatchingResourcePatternResolver().getResources("classpath*:/mapper/master/*Mapper.xml"));
return bean.getObject();
}
@Bean(name = "masterTransactionManager")
@Primary
public DataSourceTransactionManager transactionManager(@Qualifier("masterDataSource") DataSource dataSource) {
return new DataSourceTransactionManager(dataSource);
}
@Bean(name = "masterSqlSessionTemplate")
@Primary
public SqlSessionTemplate testSqlSessionTemplate(
@Qualifier("masterSqlSessionFactory") SqlSessionFactory sqlSessionFactory) throws Exception {
return new SqlSessionTemplate(sqlSessionFactory);
}
}
SlaveDataSourceConfig 对应数据库 db_test2
@Configuration
@MapperScan(basePackages = "cn.zwqh.springboot.dao.slave", sqlSessionFactoryRef = "slaveSqlSessionFactory")
public class SlaveDataSourceConfig {
@Value("${slave.datasource.driver-class-name}")
private String driverClassName;
@Value("${slave.datasource.url}")
private String url;
@Value("${slave.datasource.username}")
private String username;
@Value("${slave.datasource.password}")
private String password;
@Bean(name = "slaveDataSource")
public DataSource dataSource() {
DruidDataSource dataSource = new DruidDataSource();
dataSource.setDriverClassName(this.driverClassName);
dataSource.setUrl(this.url);
dataSource.setUsername(this.username);
dataSource.setPassword(this.password);
return dataSource;
}
@Bean(name = "slaveSqlSessionFactory")
public SqlSessionFactory sqlSessionFactory(@Qualifier("slaveDataSource") DataSource dataSource) throws Exception {
SqlSessionFactoryBean bean = new SqlSessionFactoryBean();
bean.setDataSource(dataSource);
bean.setMapperLocations(
new PathMatchingResourcePatternResolver().getResources("classpath*:/mapper/slave/*Mapper.xml"));
return bean.getObject();
}
@Bean(name = "slaveTransactionManager")
public DataSourceTransactionManager transactionManager(@Qualifier("slaveDataSource") DataSource dataSource) {
return new DataSourceTransactionManager(dataSource);
}
@Bean(name = "slaveSqlSessionTemplate")
public SqlSessionTemplate testSqlSessionTemplate(
@Qualifier("masterSqlSessionFactory") SqlSessionFactory sqlSessionFactory) throws Exception {
return new SqlSessionTemplate(sqlSessionFactory);
}
}
多个数据源在使用的过程中必须指定主库，不然会报错。
@MapperScan(basePackages = "cn.zwqh.springboot.dao.slave") 指定对应 Dao 层的扫描路径。
dao 层和 xml 层
db_test 数据库的 dao 层在 cn.zwqh.springboot.dao.master 包下，db_test2 数据库的 dao 层在 cn.zwqh.springboot.dao.slave 包下。
UserDao
public interface UserDao {
List<UserEntity> getAll();
}
HeroDao
public interface HeroDao {
List<Hero> getAllHero();
}
db_test 数据库的 xml 层在 /mapper/master/ 文件路径下，db_test2 数据库的 xml 层在 /mapper/slave/ 文件路径下。
UserMapper.xml
<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE mapper PUBLIC "-//mybatis.org//DTD Mapper 3.4//EN"
"http://mybatis.org/dtd/mybatis-3-mapper.dtd">
<mapper namespace="cn.zwqh.springboot.dao.master.UserDao">
<resultMap type="cn.zwqh.springboot.model.UserEntity" id="user">
<id property="id" column="id"/>
<result property="userName" column="user_name"/>
<result property="userSex" column="user_sex"/>
</resultMap>
<!-- 获取所有用户 -->
<select id="getAll" resultMap="user">
select * from t_user
</select>
</mapper>
HeroMapper.xml
<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE mapper PUBLIC "-//mybatis.org//DTD Mapper 3.4//EN"
"http://mybatis.org/dtd/mybatis-3-mapper.dtd">
<mapper namespace="cn.zwqh.springboot.dao.slave.HeroDao">
<resultMap type="cn.zwqh.springboot.model.Hero" id="hero">
<id property="id" column="id"/>
<result property="heroCode" column="hero_code"/>
<result property="heroName" column="hero_name"/>
</resultMap>
<!-- 获取所有用户 -->
<select id="getAllHero" resultMap="hero">
select * from t_hero
</select>
</mapper>
测试
测试可以使用 SpringBootTest,也可以放到 Controller中，个人习惯用 Controller。
@RestController
@RequestMapping("/test")
public class TestController {
@Autowired
private UserDao userDao;
@Autowired
private HeroDao heroDao;
/**
* 查找所有用户
* @return
*/
@RequestMapping("/getAllUser")
public List<UserEntity> getAllUser(){
return userDao.getAll();
}
/**
* 查找所有英雄
* @return
*/
@RequestMapping("/getAllHero")
public List<Hero> getAllHero(){
return heroDao.getAllHero();
}
}
浏览器直接访问：http://127.0.0.1:8080/test/ 加上相关测试路径即可。
总结
多数据源一般用于主从模式或者按业务分库。
示例代码
非特殊说明，本文版权归 朝雾轻寒 所有，转载请注明出处.
原文标题：Spring Boot 2.X(五)：MyBatis 多数据源配置
原文地址： https://www.zwqh.top/article/info/12
如果文章对您有帮助，请扫码关注下我的公众号，文章持续更新中...
