Dynamic switching of data sources on the Internet can not meet my current application, and switching back and forth will cause performance problems and crash. And it's not a good way to switch notes on a certain method. So think about it at the top level. Here is my configuration:
Initializing multiple spring-mybatis.xml files in web.xml

< context param > <! -- global environment parameter initialization -- >
        < param name > contextconfiglocation < / param name > <! -- parameter name -- >
        < param value > classpath: spring-mybatis.xml, classpath: spring-mybatis1.xml < / param value > <! -- parameter value, comma separated -- >
    </context-param>

Then there is spring-mybatis.xml, which is simple, convenient and has no performance problems.

<?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:context="http://www.springframework.org/schema/context"
       xsi:schemaLocation="http://www.springframework.org/schema/beans
        http://www.springframework.org/schema/beans/spring-beans-4.0.xsd

        http://www.springframework.org/schema/context

        http://www.springframework.org/schema/context/spring-context-4.0.xsd">
    <!-- Automatic scanning -->
    <context:component-scan base-package="com.tzc.webapi.service" />
    <!-- Import profile -->
    <bean id="propertyConfigurer"
          class="org.springframework.beans.factory.config.PropertyPlaceholderConfigurer">
        <property name="location" value="classpath:jdbc.properties" />
    </bean>

<!--slave library -->

    <bean id="DataSource1" class="org.apache.commons.dbcp.BasicDataSource"
          destroy-method="close">
        <property name="driverClassName" value="${slave.jdbc.driverClassName}" />
        <property name="url" value="${slave.jdbc.url}" />
        <property name="username" value="${slave.jdbc.username}" />
        <property name="password" value="${slave.jdbc.password}" />


        <!-- Configure initialization size, min, Max -->
        <property name="initialSize" value="${initialSize}" />
        <property name="minIdle" value="${minIdle}" />
        <property name="maxActive" value="${maxActive}" />

        <!-- Configure the timeout time for getting connection waiting -->
        <property name="maxWait" value="${maxWait}" />
    </bean>
    <bean id="sqlSessionFactory" class="org.mybatis.spring.SqlSessionFactoryBean">
        <property name="dataSource" ref="DataSource1" />
        <!-- Automatic scanning mapping.xml file -->
        <property name="typeAliasesPackage" value="com.tzc.webapi.bean"></property>
        <property name="mapperLocations" value="classpath:slave/*.xml"></property>
    </bean>
    <bean class="org.mybatis.spring.mapper.MapperScannerConfigurer">
        <property name="basePackage" value="com.tzc.webapi.dao.user"></property>
        <property name="sqlSessionFactoryBeanName" value="sqlSessionFactory"></property>
    </bean>
    <bean id="sqlSessionFactory1" class="org.mybatis.spring.SqlSessionFactoryBean">
        <property name="dataSource" ref="DataSource" />
        <!-- Automatic scanning mapping.xml file -->
        <property name="typeAliasesPackage" value="com.tzc.webapi.bean"></property>
        <property name="mapperLocations" value="classpath:master/*.xml"></property>
    </bean>
    <bean class="org.mybatis.spring.mapper.MapperScannerConfigurer">
        <property name="basePackage" value="com.tzc.webapi.dao.book"></property>
        <property name="sqlSessionFactoryBeanName" value="sqlSessionFactory1"></property>
    </bean>
    <!-- (transaction management)transaction manager, use JtaTransactionManager for global tx -->
    <bean id="transactionManager"
          class="org.springframework.jdbc.datasource.DataSourceTransactionManager">
        <property name="dataSource" ref="DataSource1" />
    </bean>
    <!-- Use annotation Annotation mode configuration transaction -->
    <!--<tx:annotation-driven transaction-manager="transactionManager"/>-->
    <!--<aop:aspectj-autoproxy proxy-target-class="true"></aop:aspectj-autoproxy>-->
    <!--<bean name="myAspectJ" class="com.tzc.webapi.dbRouting.DynamicDataSourceAspect"/>-->

</beans>
spring-mybatis1.xml Configuration

``

```.
<?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:context="http://www.springframework.org/schema/context"
       xsi:schemaLocation="http://www.springframework.org/schema/beans
        http://www.springframework.org/schema/beans/spring-beans-4.0.xsd
        http://www.springframework.org/schema/context
        http://www.springframework.org/schema/context/spring-context-4.0.xsd">
    <!-- Automatic scanning -->
    <context:component-scan base-package="com.tzc.webapi.service" />
    <!-- Import profile -->
    <bean id="propertyConfigurer"
          class="org.springframework.beans.factory.config.PropertyPlaceholderConfigurer">
        <property name="location" value="classpath:jdbc.properties" />
    </bean>

    <!--master library-->
    <bean id="DataSource" class="org.apache.commons.dbcp.BasicDataSource"
          destroy-method="close">
        <property name="driverClassName" value="${master.jdbc.driverClassName}" />
        <property name="url" value="${master.jdbc.url}" />
        <property name="username" value="${master.jdbc.username}" />
        <property name="password" value="${master.jdbc.password}" />
        <property name="initialSize" value="${initialSize}" />
        <property name="minIdle" value="${minIdle}" />
        <property name="maxActive" value="${maxActive}" />
        <property name="maxWait" value="${maxWait}" />
    </bean>

    <bean id="sqlSessionFactory1" class="org.mybatis.spring.SqlSessionFactoryBean">
        <property name="dataSource" ref="DataSource" />
        <!-- Automatic scanning mapping.xml file -->
        <property name="typeAliasesPackage" value="com.tzc.webapi.bean"></property>
        <property name="mapperLocations" value="classpath:master/*.xml"></property>
    </bean>
    <bean class="org.mybatis.spring.mapper.MapperScannerConfigurer">
        <property name="basePackage" value="com.tzc.webapi.dao.book"></property>
        <property name="sqlSessionFactoryBeanName" value="sqlSessionFactory1"></property>
    </bean>
    <!-- (transaction management)transaction manager, use JtaTransactionManager for global tx -->
    <bean id="transactionManager"
          class="org.springframework.jdbc.datasource.DataSourceTransactionManager">
        <property name="dataSource" ref="DataSource" />
    </bean>

</beans>

Test:

The test passed. From different data sources.

Conclusion: in fact, different data sources scan different mapper files and different Daos. Get the data in the destination database. ok