1 配置文件
在配置文件中配置两个数据源配置，以及mybatis xml配置文件路径
# mybatis 多数据源配置mybatis.config-location = classpath:mapper/config/mybatis-config.xml################# mysql 数据源1 #################spring.datasource.one.jdbc-url=jdbc:mysql://localhost:3306/user?serverTimezone=UTC&useUnicode=true&characterEncoding=utf-8&useSSL=truespring.datasource.one.username=rootspring.datasource.one.password=root#spring.datasource.one.driver-class-name=com.mysql.cj.jdbc.Driverspring.datasource.one.driver-class-name=com.mysql.jdbc.Driver################# mysql 数据源1 ################################## mysql 数据源2 ################spring.datasource.second.jdbc-url=jdbc:mysql://xxxxxxxxxx:3306/user?serverTimezone=UTC&useUnicode=true&characterEncoding=utf-8&useSSL=truespring.datasource.second.username=rootspring.datasource.second.password=root#spring.datasource.second.driver-class-name=com.mysql.cj.jdbc.Driverspring.datasource.second.driver-class-name=com.mysql.jdbc.Driver################# mysql 数据源1 #################2 数据库配置代码：
1 步骤
1 首先加载配置的数据源：手动将数据配置文件信息注入到数据源实例对象中。
2 根据创建的数据源，配置数据库实例对象注入到SqlSessionFactory 中，构建对应的 SqlSessionFactory。
3 配置数据库事务：将数据源添加到事务中。
4 将SqlSessionFactory 注入到SqlSessionTemplate 模板中
5 最后将上面创建的 SqlSessionTemplate 注入到对应的 Mapper 包路径下，这样这个包下面的 Mapper 都会使用第一个数据源来进行数据库操作。
basePackages 指明 Mapper 地址。sqlSessionTemplateRef 指定 Mapper 路径下注入的 sqlSessionTemplate。在多数据源的情况下，不需要在启动类添加：@MapperScan("com.xxx.mapper") 的注解。
2 项目结构：
3 第一个数据源
@Api("SqlSessionTemplate 注入到对应的 Mapper 包路径下")@Configuration@MapperScan(basePackages = "com.example.demo.mapper.one", sqlSessionTemplateRef = "oneSqlSessionTemplate")public class OneDataSourceConfig { //------------------ 1 加载配置的数据源： ------------------------------- @Bean("oneDatasource") @ConfigurationProperties(prefix = "spring.datasource.one") @Primary //默认是这个库 public DataSource DataSource1Config(){ return DataSourceBuilder.create().build(); } //---------------------- 2 创建的数据源 构建对应的 SqlSessionFactory。 ---------------------- @Bean(name = "oneSqlSessionFactory" ) @Primary public SqlSessionFactory oneSqlSessionFactory(@Qualifier("oneDatasource") DataSource dataSource) throws Exception { SqlSessionFactoryBean bean = new SqlSessionFactoryBean(); bean.setDataSource(dataSource); bean.setMapperLocations(new PathMatchingResourcePatternResolver().getResources("classpath:/mapper/one/*.xml")); return bean.getObject(); } //------------------------3 配置事务 -------------------------- @Bean(name = "oneTransactionManager") @Primary public DataSourceTransactionManager oneTransactionManager(@Qualifier("oneDatasource") DataSource dataSource) { return new DataSourceTransactionManager(dataSource); } //------------------------------- 4 注入 SqlSessionFactory 到 SqlSessionTemplate 中--------------------------------- @Bean(name = "oneSqlSessionTemplate") @Primary public SqlSessionTemplate oneSqlSessionTemplate(@Qualifier("oneSqlSessionFactory") SqlSessionFactory sqlSessionFactory) throws Exception { return new SqlSessionTemplate(sqlSessionFactory); }}第二个数据源
@Api("SqlSessionTemplate 注入到对应的 Mapper 包路径下")@Configuration@MapperScan(basePackages = "com.example.demo.mapper.second", sqlSessionTemplateRef = "secondSqlSessionTemplate")public class SecondDataSourceConfig { //------------------ 加载配置的数据源： ------------------------------- @Bean("secondDatasource") @ConfigurationProperties(prefix = "spring.datasource.second") public DataSource DataSource2Config(){ return DataSourceBuilder.create().build(); } //---------------------- 创建的数据源 构建对应的 SqlSessionFactory。 ---------------------- @Bean(name = "secondSqlSessionFactory") public SqlSessionFactory secondSqlSessionFactory(@Qualifier("secondDatasource") DataSource dataSource) throws Exception { SqlSessionFactoryBean bean = new SqlSessionFactoryBean(); bean.setDataSource(dataSource); bean.setMapperLocations(new PathMatchingResourcePatternResolver().getResources("classpath:/mapper/second/*.xml")); return bean.getObject(); } //------------------------ 配置事务 -------------------------- @Bean(name = "secondTransactionManager") public DataSourceTransactionManager secondTransactionManager(@Qualifier("secondDatasource") DataSource dataSource) { return new DataSourceTransactionManager(dataSource); } //------------------------------- 注入 SqlSessionFactory 到 SqlSessionTemplate 中--------------------------------- @Bean(name = "secondSqlSessionTemplate") public SqlSessionTemplate secondSqlSessionTemplate(@Qualifier("secondSqlSessionFactory") SqlSessionFactory sqlSessionFactory) throws Exception { return new SqlSessionTemplate(sqlSessionFactory); }}3 xml文件
<?xml version="1.0" encoding="UTF-8" ?><!DOCTYPE configuration PUBLIC "-//mybatis.org//DTD Config 3.0//EN" "http://mybatis.org/dtd/mybatis-3-config.dtd"><configuration></configuration>4 mapper 类
public interface User1Mapper { public void inserts(User user);}public interface User2Mapper { public void inserts(User user);}5 mybatis mapper.xml
<?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="com.example.demo.mapper.one.User1Mapper"> <insert id="inserts" parameterType="com.example.demo.pojo.User" useGeneratedKeys="true" keyProperty="id"> insert into user(`name`,age) VALUE (#{name},#{age}) </insert> </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="com.example.demo.mapper.one.User2Mapper"> <insert id="inserts" parameterType="com.example.demo.pojo.User" useGeneratedKeys="true" keyProperty="id"> insert into user(`name`,age) VALUE (#{name},#{age}) </insert> </mapper>3 启动成功
表示数据源创建成功，这里连接池采用springboot默认的Hikari数据库连接池(不需要配置)
6 测试
@Autowired User1Mapper user1Mapper; @Autowired User2Mapper user2Mapper; @Test public void test(){ user1Mapper.inserts(new User(22L, "a123456",1)); user1Mapper.inserts(new User(33L, "b123456", 1)); user2Mapper.inserts(new User(44L, "b123456", 1)); }结果
7 更换数据源配置
官方文档 ： https://github.com/alibaba/dr...
增加配置文件 , 更换为durid数据源
1 配置文件增加配置属性
# StatViewServlet 配置spring.datasource.druid.stat-view-servlet.login-username=adminspring.datasource.druid.stat-view-servlet.login-password=admin# 配置 StatFilterspring.datasource.druid.filter.stat.log-slow-sql=truespring.datasource.druid.filter.stat.slow-sql-millis=2000# Druid 数据源 1 配置spring.datasource.druid.one.initial-size=3spring.datasource.druid.one.min-idle=3spring.datasource.druid.one.max-active=10spring.datasource.druid.one.max-wait=60000# Druid 数据源 2 配置spring.datasource.druid.second.initial-size=6spring.datasource.druid.second.min-idle=6spring.datasource.druid.second.max-active=20spring.datasource.druid.second.max-wait=120000将上面数据库配置文件前缀加上druid
如：
# StatViewServlet 配置spring.datasource.druid.stat-view-servlet.login-username=adminspring.datasource.druid.stat-view-servlet.login-password=admin# 配置 StatFilterspring.datasource.druid.filter.stat.log-slow-sql=truespring.datasource.druid.filter.stat.slow-sql-millis=2000# Druid 数据源 1 配置spring.datasource.druid.one.initial-size=3spring.datasource.druid.one.min-idle=3spring.datasource.druid.one.max-active=10spring.datasource.druid.one.max-wait=60000# Druid 数据源 2 配置spring.datasource.druid.second.initial-size=6spring.datasource.druid.second.min-idle=6spring.datasource.druid.second.max-active=20spring.datasource.druid.second.max-wait=120000#mybatis.type-aliases-package = com.example.demo.pojo################# mysql 数据源1 #################spring.datasource.druid.one.url=jdbc:mysql://localhost:3306/user?serverTimezone=UTC&useUnicode=true&characterEncoding=utf-8&useSSL=truespring.datasource.druid.one.username=rootspring.datasource.druid.one.password=rootspring.datasource.druid.one.driver-class-name=com.mysql.jdbc.Driver################# mysql 数据源1 ################################## mysql 数据源2 #################spring.datasource.druid.second.url=jdbc:mysql://xxxxxxxxxxx:3306/user?serverTimezone=UTC&useUnicode=true&characterEncoding=utf-8&useSSL=truespring.datasource.druid.second.username=rootspring.datasource.druid.second.password=rootspring.datasource.druid.second.driver-class-name=com.mysql.jdbc.Driver################# mysql 数据源1 #################2 引入依赖
<!--druid--> <dependency> <groupId>com.alibaba</groupId> <artifactId>druid-spring-boot-starter</artifactId> <version>1.1.10</version> </dependency>然后在加载数据源配置哪儿读取配置文件注解改为
@ConfigurationProperties(prefix = "spring.datasource.druid.one")@ConfigurationProperties(prefix = "spring.datasource.druid.second")启动后发现配置成功
过程中可能会遇到问题
Failed to configure a DataSource: 'url' attribute is not specified and no embedded datasource could be configured.
Reason: Failed to determine a suitable driver class
原因是：url链接写错了 , SpringBoot duridd无法配置到 数据源url
错误：spring.datasource.druid.one.jdbc-url=jdbc:mysql://localhost:3306/user? 这是jdbc的url链接正确 ： spring.datasource.druid.one.url=jdbc:mysql://localhost:3306/user? 这是连接池用的url