在项目中使用多个数据源，并且在各数据源之间进行读写操作。
在项目database.properties文件里配置多个数据源。
<?xml version="1.0" encoding="UTF-8"?>
<beans xmlns="http://www.springframework.org/schema/beans"
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:p="http://www.springframework.org/schema/p"
xmlns:context="http://www.springframework.org/schema/context"
xmlns:mvc="http://www.springframework.org/schema/mvc"
xmlns:tx="http://www.springframework.org/schema/tx"
xmlns:aop="http://www.springframework.org/schema/aop"
xsi:schemaLocation="http://www.springframework.org/schema/beans
http://www.springframework.org/schema/beans/spring-beans-3.1.xsd
http://www.springframework.org/schema/context
http://www.springframework.org/schema/context/spring-context-3.1.xsd
http://www.springframework.org/schema/mvc
http://www.springframework.org/schema/mvc/spring-mvc-4.0.xsd
http://www.springframework.org/schema/tx
http://www.springframework.org/schema/tx/spring-tx-2.0.xsd
http://www.springframework.org/schema/aop
http://www.springframework.org/schema/aop/spring-aop.xsd">
<!-- 自动扫描 -->
<context:component-scan base-package="com.operation.implement" />
<!-- 引入配置文件 -->
<bean id="propertyConfigurer" class="org.springframework.beans.factory.config.PropertyPlaceholderConfigurer">
<property name="location" value="classpath:database.properties" />
</bean>
<bean id="dataSourceOperation" class="com.alibaba.druid.pool.DruidDataSource" destroy-method="close">
<property name="driverClassName" value="com.mysql.jdbc.Driver" />
<property name="url" value="${operation.url}" />
<property name="username" value="${operation.username}" />
<property name="password" value="${operation.password}" />
<!-- 初始化连接大小 -->
<property name="initialSize" value="${operation.initialSize}"></property>
<!-- 连接池最大数量 -->
<property name="maxActive" value="${operation.maxActive}"></property>
<!-- 连接池最小空闲 -->
<property name="minIdle" value="${operation.minIdle}"></property>
<!-- 超过时间限制是否回收 -->
<property name="removeAbandoned" value="true" />
<!-- 超时时间；单位为秒。360秒=6分钟 -->
<property name="removeAbandonedTimeout" value="360" />
<!-- 关闭abanded连接时输出错误日志 -->
<property name="logAbandoned" value="true" />
</bean>
<bean id="dataSource" class="com.alibaba.druid.pool.DruidDataSource" destroy-method="close">
<property name="driverClassName" value="com.mysql.jdbc.Driver" />
<property name="url" value="${url}" />
<property name="username" value="${username}" />
<property name="password" value="${password}" />
<!-- 初始化连接大小 -->
<property name="initialSize" value="${initialSize}"></property>
<!-- 连接池最大数量 -->
<property name="maxActive" value="${maxActive}"></property>
<!-- 连接池最小空闲 -->
<property name="minIdle" value="${minIdle}"></property>
<!-- 超过时间限制是否回收 -->
<property name="removeAbandoned" value="true" />
<!-- 超时时间；单位为秒。360秒=6分钟 -->
<property name="removeAbandonedTimeout" value="360" />
<!-- 关闭abanded连接时输出错误日志 -->
<property name="logAbandoned" value="true" />
</bean>
<bean id="sqlSessionFactoryOperation" class="org.mybatis.spring.SqlSessionFactoryBean">
<property name="dataSource" ref="dataSourceOperation" />
<property name="mapperLocations" value="classpath:com/operation/data/operation/*.xml"></property>
</bean>
<bean id="sqlSessionFactory" class="org.mybatis.spring.SqlSessionFactoryBean">
<property name="dataSource" ref="dataSource" />
<property name="mapperLocations" value="classpath:com/operation/data/test/*.xml"></property>
</bean>
<bean class="org.mybatis.spring.mapper.MapperScannerConfigurer">
<property name="basePackage" value="com.operation.dao.operation" />
<property name="sqlSessionFactoryBeanName" value="sqlSessionFactoryOperation"/>
</bean>
<bean class="org.mybatis.spring.mapper.MapperScannerConfigurer">
<property name="basePackage" value="com.operation.dao.test" />
<property name="sqlSessionFactoryBeanName" value="sqlSessionFactory"/>
</bean>
<bean id="sqlSessionOperation" class="org.mybatis.spring.SqlSessionTemplate" scope="prototype">
<constructor-arg index="0" ref="sqlSessionFactoryOperation"/>
</bean>
<bean id="sqlSession" class="org.mybatis.spring.SqlSessionTemplate" scope="prototype">
<constructor-arg index="0" ref="sqlSessionFactory"/>
</bean>
<bean id="transactionManagerOperation" class="org.springframework.jdbc.datasource.DataSourceTransactionManager">
<property name="dataSource" ref="dataSourceOperation" />
</bean>
<tx:annotation-driven transaction-manager="transactionManagerOperation" proxy-target-class="true" />
<bean id="transactionManager" class="org.springframework.jdbc.datasource.DataSourceTransactionManager">
<property name="dataSource" ref="dataSource" />
</bean>
<tx:annotation-driven transaction-manager="transactionManager" proxy-target-class="true" />
</beans>
以上是spring-mybatis.xml文件的配置文件。dataSourceOperation和dataSource是两个不同的数据源。
<bean id="sqlSessionFactoryOperation" class="org.mybatis.spring.SqlSessionFactoryBean">
<property name="dataSource" ref="dataSourceOperation" />
<property name="mapperLocations" value="classpath:com/operation/data/operation/*.xml"></property>
</bean>
<bean id="sqlSessionFactory" class="org.mybatis.spring.SqlSessionFactoryBean">
<property name="dataSource" ref="dataSource" />
<property name="mapperLocations" value="classpath:com/operation/data/test/*.xml"></property>
</bean>
可以看出mybatis配置的sql文件在不同的包下。
<bean class="org.mybatis.spring.mapper.MapperScannerConfigurer">
<property name="basePackage" value="com.operation.dao.operation" />
<property name="sqlSessionFactoryBeanName" value="sqlSessionFactoryOperation"/>
</bean>
<bean class="org.mybatis.spring.mapper.MapperScannerConfigurer">
<property name="basePackage" value="com.operation.dao.test" />
<property name="sqlSessionFactoryBeanName" value="sqlSessionFactory"/>
</bean>
MapperScannerConfigurer将扫描basePackage所指定的包下的所有接口类（包括子类），如果它们在SQL映射文件中定义过，则将它们动态定义为一个Spring Bean，这样，我们在Service中就可以直接注入映射接口的bean。
MapperScannerConfigurer的理解，参考https://www.cnblogs.com/wade-luffy/p/6094236.html