Spring+Hibernate框架下Mysql读写分离、主从数据库配置

shuijingping

介绍下mysql数据库读写分离在spring,hibernate框架下的配置。
1.mysql连接配置文件jdbc.properties
master.*.*表示主数据库连接参数，负责增，删，改；
slave.*.*表示从数据库连接参数，只负责读取；
jdbc.properties

master.jdbc.driverClassName=com.mysql.jdbc.Driver
master.jdbc.url=********
master.jdbc.username=********
master.jdbc.password=********
slave.jdbc.driverClassName=com.mysql.jdbc.Driver
slave.jdbc.url=********
slave.jdbc.username=********
slave.jdbc.password=********
把**改成你所需的连接参数；
2.配置AOP切面类 DataSourceAdvice.java

import java.lang.reflect.Method;
import org.springframework.aop.AfterReturningAdvice;
import org.springframework.aop.MethodBeforeAdvice;
import org.springframework.aop.ThrowsAdvice;
import com.company.datasource.DataSourceSwitcher;
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");
}
}

数据源选择类 DataSourceSwitcher.java

package com.company.datasource;
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();
}
}


DynamicDataSource.java数据源动态切换类

package com.company.datasource;
import org.springframework.jdbc.datasource.lookup.AbstractRoutingDataSource;
public class DynamicDataSource extends AbstractRoutingDataSource {
@Override
protected Object determineCurrentLookupKey() {
return DataSourceSwitcher.getDataSource();
}
}


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:aop="http://www.springframework.org/schema/aop"
xmlns:tx="http://www.springframework.org/schema/tx" xmlns:context="http://www.springframework.org/schema/context"
xsi:schemaLocation="
http://www.springframework.org/schema/beans
http://www.springframework.org/schema/beans/spring-beans-3.0.xsd
http://www.springframework.org/schema/tx
http://www.springframework.org/schema/tx/spring-tx-3.0.xsd
http://www.springframework.org/schema/aop
http://www.springframework.org/schema/aop/spring-aop-3.0.xsd
http://www.springframework.org/schema/context
http://www.springframework.org/schema/context/spring-context-3.0.xsd">
<context:annotation-config />
<!-- 自动加载SERVICE DAO ACTION -->
<context:component-scan base-package="cn.com.company.dao.*" />
<context:component-scan base-package="cn.com.company.service.*" />
<context:component-scan base-package="cn.com.company.action" />
<!-- 加载properties配置文件 -->
<bean id="propertyConfigurer"
class="org.springframework.beans.factory.config.PropertyPlaceholderConfigurer">
<property name="locations">
<list>
<value>classpath:jdbc.properties</value>
</list>
</property>
</bean>
<bean id="parentDataSource" class="com.mchange.v2.c3p0.ComboPooledDataSource">
//***c3p0配置
</bean>
<!-- 主数据源-->
<bean id="masterDataSource" parent="parentDataSource">
<property name="driverClass" value="${master.jdbc.driverClassName}" />
<property name="jdbcUrl" value="${master.jdbc.url}" />
<property name="user" value="${master.jdbc.username}" />
<property name="password" value="${master.jdbc.password}" />
</bean>
<!-- 从数据源-->
<bean id="slaveDataSource" parent="parentDataSource">
<property name="driverClass" value="${slave.jdbc.driverClassName}" />
<property name="jdbcUrl" value="${slave.jdbc.url}" />
<property name="user" value="${slave.jdbc.username}" />
<property name="password" value="${slave.jdbc.password}" />
</bean>
<bean id="dataSource" class="com.company.datasource.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.annotation.AnnotationSessionFactoryBean">
<property name="dataSource" ref="dataSource"></property>
<property name="packagesToScan" value="cn.com.company.entity" />
<property name="hibernateProperties">
<props>
<prop>//***hibernate一些参数这里不写了</prop>
</props>
</property>
</bean>
<!-- 切换数据源 -->
<bean id="dataSourceAdvice" class="com.company.aop.DataSourceAdvice" />
<aop:config>
<aop:advisor
pointcut="execution(* cn.com.company.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="loadByUsername*" 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(* cn.com.company.service..*Service.*(..))"
advice-ref="txAdvice" />
<aop:advisor
pointcut="execution(* cn.com.company.service..*ServiceImpl.*(..))"
advice-ref="txAdvice" />
</aop:config>

</beans>


！注 applicationContenxt.xml中
<!-- 切换数据源 -->
<bean id="dataSourceAdvice" class="com.company.aop.DataSourceAdvice" />
<aop:config>
<aop:advisor
pointcut="execution(* cn.com.company.service..*Service.*(..))"
advice-ref="dataSourceAdvice" />
</aop:config>
一定要配置在事务AOP之上