注：自动切换，是为不同的数据源，却要对应相同的dao层；
1.与无事务版的一样，创建DynamicDataSource类，继承AbstractRoutingDataSource
package com.test.main.dataSource;
import org.springframework.jdbc.datasource.lookup.AbstractRoutingDataSource;
public class DynamicDataSource extends AbstractRoutingDataSource {
@Override
protected Object determineCurrentLookupKey() {
return DynamicDataSourceHolder.getDataSource();
}
}
创建辅助类DynamicDataSourceHolder，主要用于保存当前线程所需的datasource的key值
package com.test.main.dataSource;
public class DynamicDataSourceHolder {
private static final ThreadLocal<String> THREAD_DATA_SOURCE = new ThreadLocal<String>();
public static String getDataSource() {
return THREAD_DATA_SOURCE.get();
}
public static void setDataSource(String dataSource) {
THREAD_DATA_SOURCE.set(dataSource);
}
public static void clearDataSource() {
THREAD_DATA_SOURCE.remove();
}
}
创建dao层切面，注解选择数据源DataSourceAspect类：
package com.test.main.dataSource; import java.lang.annotation.Annotation;
import java.lang.reflect.Method; import org.aspectj.lang.JoinPoint;
import org.aspectj.lang.annotation.Aspect;
import org.aspectj.lang.annotation.Before;
import org.aspectj.lang.reflect.MethodSignature;
import org.springframework.stereotype.Component; import com.test.main.annotations.DataSource; @Component
@Aspect
public class DataSourceAspect {
@Before("execution(* com.test.model.dao.*.*.*(..))")
public void intercept(JoinPoint point) throws Exception {
Class<?> target = point.getTarget().getClass();
MethodSignature signature = (MethodSignature) point.getSignature();
for (Class<?> clazz : target.getInterfaces()) {
resolveDataSource(clazz, signature.getMethod());
}
resolveDataSource(target, signature.getMethod()); }
private void resolveDataSource(Class<?> clazz, Method method) {
String sourceName = null;
try {
Class<?>[] types = method.getParameterTypes();
if (clazz.isAnnotationPresent((Class<? extends Annotation>) DataSource.class)) {
DataSource source = clazz.getAnnotation(DataSource.class);
sourceName = source.value();
DynamicDataSourceHolder.setDataSource(sourceName);
}
Method m = clazz.getMethod(method.getName(), types);
if (m != null && m.isAnnotationPresent(DataSource.class)) {
DataSource source = m.getAnnotation(DataSource.class);
sourceName = source.value();
DynamicDataSourceHolder.setDataSource(sourceName);
}
} catch (Exception e) {
System.out.println(clazz + ":" + e.getMessage());
}
} }
2.spring-db.xml 配置：
<?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:util="http://www.springframework.org/schema/util"
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.xsd
http://www.springframework.org/schema/aop http://www.springframework.org/schema/aop/spring-aop-4.2.xsd
http://www.springframework.org/schema/tx http://www.springframework.org/schema/tx/spring-tx-4.2.xsd
http://www.springframework.org/schema/util http://www.springframework.org/schema/util/spring-util-4.2.xsd"> <util:properties id="jdbc"
location="classpath:etc/mybatis/db.properties" /> <!-- 连接池配置开始 -->
<bean id="base" class="com.alibaba.druid.pool.xa.DruidXADataSource"
destroy-method="close" lazy-init="true">
<property name="initialSize" value="5" />
<property name="minIdle" value="5" />
<property name="maxActive" value="20" /> <property name="validationQuery" value="SELECT 1" />
<property name="timeBetweenEvictionRunsMillis" value="2800000" />
<property name="minEvictableIdleTimeMillis" value="600000" />
<property name="testWhileIdle" value="true" />
<property name="testOnBorrow" value="false" />
<property name="testOnReturn" value="false" />
<property name="filters" value="stat" /> <property name="logAbandoned" value="true" />
</bean> <!-- Druid连接池 -->
<bean id="jpcar" parent="base">
<property name="driverClassName" value="#{jdbc.driverClassName}" />
<property name="url" value="#{jdbc.jpcar_url}" />
<property name="username" value="#{jdbc.username}" />
<property name="password" value="#{jdbc.password}" />
</bean>
<bean id="jpcarAtom" class="com.atomikos.jdbc.AtomikosDataSourceBean"
init-method="init" destroy-method="close">
<property name="uniqueResourceName" value="mysql/jpcar" />
<property name="xaDataSource" ref="jpcar" />
<property name="maintenanceInterval" value="28000" />
<property name="testQuery" value="SELECT 1" />
</bean>
<bean id="jpcarData" parent="base">
<property name="driverClassName" value="#{jdbc.driverClassName}" />
<property name="url" value="#{jdbc.jpcarData_url}" />
<property name="username" value="#{jdbc.username}" />
<property name="password" value="#{jdbc.password}" />
</bean>
<bean id="jpcarDataAtom" class="com.atomikos.jdbc.AtomikosDataSourceBean"
init-method="init" destroy-method="close">
<property name="uniqueResourceName" value="mysql/jpcarData" />
<property name="xaDataSource" ref="jpcarData" />
<property name="maintenanceInterval" value="28000" />
<property name="testQuery" value="SELECT 1" />
</bean> <bean id="test_jpcar" parent="base">
<property name="driverClassName" value="#{jdbc.driverClassName}" />
<property name="url" value="#{jdbc.test_jpcar_url}" />
<property name="username" value="#{jdbc.test_username}" />
<property name="password" value="#{jdbc.test_password}" /> </bean>
<bean id="test_jpcarAtom" class="com.atomikos.jdbc.AtomikosDataSourceBean"
init-method="init" destroy-method="close">
<property name="uniqueResourceName" value="mysql/test_jpcar" />
<property name="xaDataSource" ref="test_jpcar" />
<property name="maintenanceInterval" value="28000" />
<property name="testQuery" value="SELECT 1" />
</bean>
<bean id="test_jpcarData" parent="base">
<property name="driverClassName" value="#{jdbc.driverClassName}" />
<property name="url" value="#{jdbc.test_jpcarData_url}" />
<property name="username" value="#{jdbc.test_username}" />
<property name="password" value="#{jdbc.test_password}" /> </bean>
<bean id="test_jpcarDataAtom" class="com.atomikos.jdbc.AtomikosDataSourceBean"
init-method="init" destroy-method="close">
<property name="uniqueResourceName" value="mysql/test_jpcarData" />
<property name="xaDataSource" ref="test_jpcarData" />
<property name="maintenanceInterval" value="28000" />
<property name="testQuery" value="SELECT 1" />
</bean>
<!-- 连接池配置结束 --> <!-- MyBatis整合开始 --> <bean id="jpcarDataDynamicDataSource" class="com.jpcar.main.dataSource.DynamicDataSource">
<property name="targetDataSources">
<map key-type="java.lang.String">
<entry key="jpcar" value-ref="jpcarAtom"></entry>
<entry key="jpcarData" value-ref="jpcarDataAtom"></entry>
<entry key="test_jpcarData" value-ref="test_jpcarDataAtom"></entry>
<entry key="test_jpcar" value-ref="test_jpcarData"></entry>
</map>
</property>
</bean>
<bean id="jpcarDataFactory" class="org.mybatis.spring.SqlSessionFactoryBean">
<property name="dataSource" ref="jpcarDataDynamicDataSource" />
<property name="configLocation" value="classpath:etc/mybatis/mybatis-config.xml" />
<property name="mapperLocations" value="classpath:com/**/*.xml" />
</bean>
<bean class="org.mybatis.spring.mapper.MapperScannerConfigurer">
<property name="basePackage" value="com.jpcar" />
<property name="annotationClass" value="com.jpcar.main.annotations.MyBatisRepository" />
<property name="sqlSessionFactory" ref="jpcarDataFactory"></property>
<property name="sqlSessionFactoryBeanName" value="jpcarDataFactory"></property>
</bean> <!-- MyBatis整合结束 --> <!-- 配置数据库事务开始 -->
<!-- atomikos事务管理器 -->
<bean id="atomikosTransactionManager" class="com.atomikos.icatch.jta.UserTransactionManager"
init-method="init" destroy-method="close">
<description>UserTransactionManager</description>
<property name="forceShutdown">
<value>true</value>
</property>
</bean>
<bean id="atomikosUserTransaction" class="com.atomikos.icatch.jta.UserTransactionImp">
<property name="transactionTimeout" value="90000" />
</bean>
<bean id="springTransactionManager"
class="org.springframework.transaction.jta.JtaTransactionManager">
<property name="transactionManager">
<ref bean="atomikosTransactionManager" />
</property>
<property name="userTransaction">
<ref bean="atomikosUserTransaction" />
</property>
<property name="allowCustomIsolationLevels" value="true" />
</bean> <tx:annotation-driven transaction-manager="springTransactionManager" />
<!-- 配置数据库事务结束 --> </beans>
2.1在同一个事务中，不同的数据源需要不同 SqlSessionFactoryBean，注意配置时，需要配置 MapperScannerConfigurer的：
<property name="sqlSessionFactoryBeanName" value="cFactory"></property>
value值为：SqlSessionFactoryBean 的 bean id；
2.2同一事务中的SqlSessionFactoryBean，对应MapperScannerConfigurer 中的 basePackage 不能范围重合，不然在同一事务时，spring不会切换数据源，而是取先前与之重合的SqlSessionFactoryBean的数据源