Multiple data source configuration of Spring+Mybatis

In the same applicationContext.xml:

1. Configure multiple data sources (using connection pool c3p0, direct jdbc connection is also fine)

Data Source 1: dataSource1

<bean id = "dataSource1" class= "com.mchange.v2.c3p0.ComboPooledDataSource" lazy-init = "default">

<property name="driverClass" value = ""/>

...

...

</bean>

Data Source 2: dataSource2

<bean id = "dataSource2" class= "com.mchange.v2.c3p0.ComboPooledDataSource" lazy-init = "default">

<property name="driverClass" value = ""/>

...

...

</bean>

2, Configure mybatis data session management (sqlSessionFactoryBean)

Session factory1: sqlSessionFactoryBean1

<bean id = "sqlSessionFactoryBean1" class = "mybatis.spring.SqlSessionFactoryBean">

<property name = "mapperLocations">

<list>

//Different factories, try to keep their mapper paths different

<value>classpath:mapper/*Mapper.xml</value> //classpath指的是：src/main/resources(maven项目文件包结构哦)

</list>

</property>

<property name = "dataSource" ref = "dataSource1"></property>

</bean>

会话factory2：sqlSessionFactoryBean2

<bean id = "sqlSessionFactoryBean2" class = "mybatis.spring.SqlSessionFactoryBean">

<property name = "mapperLocations">

<list>

<value>classpath:mapper/*Mapper.xml</value> 

</list>

</property>

<property name = "dataSource" ref = "dataSource2"></property>

</bean>

3， 配置Dao接口层（重点注意）

mybatis用mapperScannerConfigurer扫描相关的dao(或mapper)的interface的包，将其注入到spring进行管理；

dao层需要注入第2步配置的sessionFactory来获得session(session中加入事物等操作)，跟sessionFactory中配置的*Mapper.xml进行一一匹配；

mapperScanner1:

<bean id="mapperScanner1" class="org.mybatis.spring.mapper.MapperScannerConfigurer">

//不同数据源的扫描dao层不要放在一起，不然数据源1扫描了数据源2的dao，那 去数据源1的mappe.xml中匹配时，会找不到相应方法，而报错！！！

<property name = "basePackage" value = "com.business.*.*dao1"/> 

//配置dao层需注入的sessionFactory

<property name = "sqlSessionFactoryBeanName" value = " sqlSessionFactoryBean1"/>

</bean>

mapperScanner2:

<bean id="mapperScanner2" class="org.mybatis.spring.mapper.MapperScannerConfigurer">

<property name = "basePackage" value = "com.business.*.*dao2"/> 

<property name = "sqlSessionFactoryBeanName" value = " sqlSessionFactoryBean2"/>

</bean>

其他配置：事物配置（dataSourceTransactionManager）,持久化模板（SqlSessionTemplate）

常见错误1：

No unique bean of type [org.apache.ibatis.sessioin.SqlSessionFactory] is defined:expected single matching bean but found 2:[sqlSessionFactoryBean1,sqlSessionFactoryBean2]

解决问题：检查步骤3配置，是否有配置sqlSessionFactoryBeanName

常见错误2：

...Dao conflicts with existing, non-compatible bean definition of same name and class[org.mybatis.spring.mapper.MapperFactoryBean]

解决问题：检查步骤3配置，属性basePackage，两个数据源是否扫描了同一dao层包，若是，更改dao层包，不同数据源需扫描不同的dao层包。

参考：http://stackoverflow.com/questions/4746766/spring-and-mybatis-multiple-data-sources-setup