分享我的开源项目-spring+mybatis实现读写分离

#### 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
开源项目地址：https://github.com/tangyanbo/springmore
* 快速入门
maven依赖
``` xml
<dependency>
<groupId>org.springmore</groupId>
<artifactId>springmore-core</artifactId>
<version>1.0.0</version>
</dependency>
```
dataSource配置(applicationContext.xml中)
``` xml
<?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)
``` xml
<!-- 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)
``` xml
<!-- 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：
``` java
@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);
}
}
```

结束了？不是吧

附上地址:https://github.com/tangyanbo/springmore

iteye都不支持markdown，实在无语了，不想发文章了

为何不用驱动层的读写分离

什么叫驱动层，只有2种办法吧，一种是在jdbc的前面，一种只在jdbc的后面，后者需要建立中间服务，解析sql协议，这太重量级了

看你用的是mysql驱动 ，mysql驱动底层是可以做读写分离:jdbc:mysql:replication，实际应用可能太重

你是怎么知道这个地址的？

请叫我大大神