spring+mybatis实现读写分离

springmore-core

spring+ibatis实现读写分离

• 特点
  无缝结合spring+ibatis，对于程序员来说，是透明的
  除了修改配置信息之外，程序的代码不需要修改任何东西
  支持spring的容器事务

• 规则:
  

1. 基于spring配置的容器事务
   
2. 读写事务到主库
   
3. 只读事务到从库
   
4. 如果没有配置事务，更新语句全部到主库，查询语句均衡到从库
   实现源码：https://gitcafe.com/tangyanbo/springmore
   下载spring-core即可

• 快速入门
  maven依赖

  <dependency>
  	<groupId>org.springmore</groupId>
  	<artifactId>springmore-core</artifactId>
  	<version>1.0.0</version>
  </dependency>

  dataSource配置(applicationContext.xml中)

  <?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-3.0.xsd
  		http://www.springframework.org/schema/context
  		http://www.springframework.org/schema/context/spring-context-3.0.xsd
  		">
  	<!-- C3P0连接池配置 -->
  	<bean id="master" class="com.mchange.v2.c3p0.ComboPooledDataSource">
  		<property name="driverClass">
  			<value>com.mysql.jdbc.Driver</value>
  		</property>
  		<property name="jdbcUrl">
  			<value>jdbc:mysql://192.168.1.246:3306/db1</value>
  		</property>
  		<property name="user">
  			<value>ysb</value>
  		</property>
  		<property name="password">
  			<value>ysb</value>
  		</property>
  		<property name="initialPoolSize">
  			<value>20</value>
  		</property>
  		<property name="minPoolSize">
  			<value>20</value>
  		</property>
  		<property name="maxPoolSize">
  			<value>200</value>
  		</property>
  		<property name="maxIdleTime">
  			<value>255000</value>
  		</property>
  	</bean>
  
  <bean id="dataSource2" class="com.mchange.v2.c3p0.ComboPooledDataSource">
  	<property name="driverClass">
  		<value>com.mysql.jdbc.Driver</value>
  	</property>
  	<property name="jdbcUrl">
  		<value>jdbc:mysql://192.168.1.246:3306/db2</value>
  	</property>
  	<property name="user">
  		<value>ysb</value>
  	</property>
  	<property name="password">
  		<value>ysb</value>
  	</property>
  	<property name="initialPoolSize">
  		<value>20</value>
  	</property>
  	<property name="minPoolSize">
  		<value>20</value>
  	</property>
  	<property name="maxPoolSize">
  		<value>200</value>
  	</property>
  	<property name="maxIdleTime">
  		<value>255000</value>
  	</property>
  </bean>
  
  <bean id="dataSource3" class="com.mchange.v2.c3p0.ComboPooledDataSource">
  	<property name="driverClass">
  		<value>com.mysql.jdbc.Driver</value>
  	</property>
  	<property name="jdbcUrl">
  		<value>jdbc:mysql://192.168.1.246:3306/db3</value>
  	</property>
  	<property name="user">
  		<value>ysb</value>
  	</property>
  	<property name="password">
  		<value>ysb</value>
  	</property>
  	<property name="initialPoolSize">
  		<value>20</value>
  	</property>
  	<property name="minPoolSize">
  		<value>20</value>
  	</property>
  	<property name="maxPoolSize">
  		<value>200</value>
  	</property>
  	<property name="maxIdleTime">
  		<value>255000</value>
  	</property>
  </bean>
  
  <bean id="dataSource" class="org.springmore.core.datasource.DynamicDataSource">
  	<property name="master" ref="master" />		
  	<property name="slaves">
  		<list>
  			<ref bean="dataSource2"/>
  			<ref bean="dataSource3"/>
  		</list>			
  	</property>
  </bean>
  </beans>

整合mybatis配置(applicationContext.xml中)

	<!-- ibatis3 工厂类 -->
	<bean id="sqlSessionFactory" class="org.mybatis.spring.SqlSessionFactoryBean">
		<property name="dataSource" ref="dataSource" />
		<property name="configLocation" value="classpath:sqlMapConfig.xml" />
	</bean>
	<bean id="sqlSessionTemplate" class="org.mybatis.spring.SqlSessionTemplate">
		<constructor-arg index="0" ref="sqlSessionFactory" />
	</bean>
	
	<bean id="dynamicSqlSessionTemplate" class="org.springmore.core.datasource.DynamicSqlSessionTemplate">
		<constructor-arg index="0" ref="sqlSessionTemplate" />
	</bean>

事务配置(applicationContext.xml中)

	<!-- 定义单个jdbc数据源的事务管理器 -->
	<bean id="transactionManager"
		class="org.springmore.core.datasource.DynamicDataSourceTransactionManager">
		<property name="dataSource" ref="dataSource" />
	</bean>
	<!-- 以 @Transactional 标注来定义事务  -->
	<tx:annotation-driven transaction-manager="transactionManager"
		proxy-target-class="true" />		
	
	<!-- 配置事务的传播特性 -->
	<tx:advice id="txAdvice" transaction-manager="transactionManager">
		<tx:attributes>
			<tx:method name="insert*" propagation="REQUIRED" read-only="false"
				rollback-for="Exception" />
			<tx:method name="delete*" propagation="REQUIRED" read-only="false"
				rollback-for="Exception" />
			<tx:method name="update*" propagation="REQUIRED" read-only="false"
				rollback-for="Exception" />
			<tx:method name="proc*" propagation="REQUIRED" read-only="false"
				rollback-for="Exception" />
			<tx:method name="select*" read-only="true" />
			<tx:method name="*" read-only="false" />
			<!-- <tx:method name="*" read-only="true" /> -->
		</tx:attributes>
	</tx:advice>
	<!-- 那些类的哪些方法参与事务 -->
	<aop:config>
		<aop:pointcut id="allManagerMethod" expression="execution(* org.springmore.core.dao..*(..))" />
		<aop:advisor pointcut-ref="allManagerMethod" advice-ref="txAdvice" />
	</aop:config>

dao代码示例：

@Repository("UserMapperImpl")
public class UserMapperImpl implements UserMapper{
	
	@Autowired
	private DynamicSqlSessionTemplate sqlSessionTemplate;

	//从库
	public List<User> selectByUserNameAndPwd(User user) {
		return sqlSessionTemplate.selectList("selectByUserNameAndPwd", user);
	}

	//主库
	public void insert(User user) {	
		sqlSessionTemplate.insert("insert", user);		
	}
}