Spring+Hibernate框架下Mysql读写分离、主从数据库配置

1. 配置AOP切面类 DataSourceAdvice.java

package until;
import java.lang.reflect.Method;
import org.springframework.aop.AfterReturningAdvice;
import org.springframework.aop.MethodBeforeAdvice;
import org.springframework.aop.ThrowsAdvice;
public class DataSourceAdvice implements MethodBeforeAdvice, AfterReturningAdvice, ThrowsAdvice {
// service方法执行之前被调用
public void before(Method method, Object[] args, Object target) throws Throwable {
System.out.println("切入点: " + target.getClass().getName() + "类中" + method.getName() + "方法");
if(method.getName().startsWith("add") 
|| method.getName().startsWith("create")
|| method.getName().startsWith("save")
|| method.getName().startsWith("edit")
|| method.getName().startsWith("update")
|| method.getName().startsWith("delete")
|| method.getName().startsWith("remove")){
System.out.println("切换到: master");
DataSourceSwitcher.setMaster();
}
else {
System.out.println("切换到: slave");
DataSourceSwitcher.setSlave();
}
}
// service方法执行完之后被调用
public void afterReturning(Object arg0, Method method, Object[] args, Object target) throws Throwable {
}
// 抛出Exception之后被调用
public void afterThrowing(Method method, Object[] args, Object target, Exception ex) throws Throwable {
DataSourceSwitcher.setSlave();
System.out.println("出现异常,切换到: slave");
}
}

2.数据源选择类 DataSourceSwitcher.java

package until;
import org.springframework.util.Assert;
public class DataSourceSwitcher {
@SuppressWarnings("rawtypes")
private static final ThreadLocal contextHolder = new ThreadLocal();
@SuppressWarnings("unchecked")
public static void setDataSource(String dataSource) {
Assert.notNull(dataSource, "dataSource cannot be null");
contextHolder.set(dataSource);
}
public static void setMaster(){
clearDataSource();
}
public static void setSlave() {
setDataSource("slave");
}
public static String getDataSource() {
return (String) contextHolder.get();
}
public static void clearDataSource() {
contextHolder.remove();
}
}

3. DynamicDataSource.java数据源动态切换类

package until;
import java.sql.SQLFeatureNotSupportedException;
import java.util.logging.Logger;
import org.springframework.jdbc.datasource.lookup.AbstractRoutingDataSource;
public class DynamicDataSource extends AbstractRoutingDataSource {
@Override
protected Object determineCurrentLookupKey() {
return DataSourceSwitcher.getDataSource();
}
}

4. 下面配置spring applicationContext.xml文件

<?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" 
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-2.5.xsd 
http://www.springframework.org/schema/context 
http://www.springframework.org/schema/context/spring-context-2.5.xsd 
http://www.springframework.org/schema/tx
http://www.springframework.org/schema/tx/spring-tx-2.5.xsd 
http://www.springframework.org/schema/aop 
http://www.springframework.org/schema/aop/spring-aop-2.5.xsd">

<!-- dbcp数据源 -->
<bean id="parentDataSource" class="org.apache.commons.dbcp.BasicDataSource" destroy-method="close">
<!-- 
<property name="driverClassName" value="com.mysql.jdbc.Driver" />
<property name="url" value="jdbc:mysql://127.0.0.1:3306/readandwrite_test" />
<property name="username" value="root" />
<property name="password" value="root" />
-->
<property name="initialSize" value="10"/><!-- 初始化连接 -->
<property name="maxIdle" value="50"/><!-- 最大空闲连接 -->
<property name="minIdle" value="10"/><!-- 最小空闲连接 -->
<property name="maxActive" value="300"/><!-- 最大连接数量 -->
<property name="logAbandoned" value="true"/><!-- 是否在自动回收超时连接的时候打印连接的超时错误 -->
<property name="removeAbandoned" value="true"/><!-- 是否自动回收超时连接 -->
<property name="removeAbandonedTimeout" value="180"/><!-- 超时时间(以秒数为单位) -->
<property name="maxWait" value="1000"/> <!--超时等待时间以毫秒为单位 -->

<property name="testOnBorrow" value="false"/> <!-- 数据库连接池中取得连接时，对其的有效性进行检查 ,会影响一定性能-->
<property name="testWhileIdle" value="true"/> <!--异步Evict的TimerTask定时线程进行控制 定时对线程池中的链接进行validateObject校验-->
<property name="timeBetweenEvictionRunsMillis" value="25200000"/><!--失效检查线程运行时间间隔 大于0才会开启evict检查线程-->
<property name="validationQuery" value="select 1"/> <!-- 校验sql-->
</bean>
<!-- 主数据源-->
<bean id="masterDataSource" parent="parentDataSource">
<property name="driverClassName" value="com.mysql.jdbc.Driver" />
<property name="url" value="jdbc:mysql://127.0.0.1:3306/readandwrite_test" />
<property name="username" value="root" />
<property name="password" value="root" />
</bean>
<!-- 从数据源-->
<bean id="slaveDataSource" parent="parentDataSource">
<property name="driverClassName" value="com.mysql.jdbc.Driver" />
<property name="url" value="jdbc:mysql://127.0.0.1:3306/readandwrite_test" />
<property name="username" value="root" />
<property name="password" value="root" />
</bean>

<!-- 数据源动态切换 -->
<bean id="dataSource" class="until.DynamicDataSource">
<property name="targetDataSources">
<map key-type="java.lang.String">
<entry key="slave" value-ref="slaveDataSource" />
</map>
</property>
<property name="defaultTargetDataSource" ref="masterDataSource" />
</bean>

<!-- 配置sessionFactory -->
<bean id="sessionFactory" class="org.springframework.orm.hibernate3.LocalSessionFactoryBean">
<property name="dataSource" ref="dataSource"></property>
<property name="mappingResources">
<list>
<value>hbm/User.hbm.xml</value>
</list>
</property>
<property name="hibernateProperties">
<props>
<prop key="hibernate.dialect">org.hibernate.dialect.MySQLDialect</prop>
<prop key="hibernate.show_sql">true</prop> 
</props>
</property>
</bean>

<!-- 切换数据源 -->
<bean id="dataSourceAdvice" class="until.DataSourceAdvice" />
<aop:config>
<aop:advisor
pointcut="execution(* service..*Service.*(..))"
advice-ref="dataSourceAdvice" />
</aop:config>

<!-- 配置事务管理器 -->
<bean id="transactionManager" class="org.springframework.orm.hibernate3.HibernateTransactionManager">
<property name="sessionFactory">
<ref bean="sessionFactory" />
</property>
</bean>
<!--配置事务的传播特性 -->
<tx:advice id="txAdvice" transaction-manager="transactionManager">
<tx:attributes>
<!-- 对增、删、改方法进行事务支持 -->
<tx:method name="add*" propagation="REQUIRED" />
<tx:method name="create*" propagation="REQUIRED" />
<tx:method name="save*" propagation="REQUIRED" />
<tx:method name="edit*" propagation="REQUIRED" />
<tx:method name="update*" propagation="REQUIRED" />
<tx:method name="delete*" propagation="REQUIRED" />
<tx:method name="remove*" propagation="REQUIRED" />
<!-- 对查找方法进行只读事务 -->
<tx:method name="load*" propagation="SUPPORTS" read-only="true" />
<!-- 对其它方法进行只读事务 -->
<tx:method name="*" propagation="SUPPORTS" read-only="true" />
</tx:attributes>
</tx:advice>
<!--那些类的哪些方法参与事务 -->
<aop:config>
<aop:advisor
pointcut="execution(* service..*Service.*(..))"
advice-ref="txAdvice" />
<aop:advisor
pointcut="execution(* service..*ServiceImpl.*(..))"
advice-ref="txAdvice" />
</aop:config>
</beans>