okay-rwdb

基于Spring AOP和Mybatis实现的数据库读写分离
多个从库支持随机路由和轮询路由

使用说明：
1、spring配置文件参考

<bean id="masterDataSource" class="com.mchange.v2.c3p0.ComboPooledDataSource"
    destroy-method="close">
    <property name="driverClass" value="${jdbc.driver}" ></property>
    <property name="jdbcUrl" value="${jdbc.url}" ></property>
    <property name="user" value="${jdbc.username}" ></property>
    <property name="password" value="${jdbc.password}" ></property>
    <property name="initialPoolSize" value="${pool.initialPoolSize}" ></property>
    <property name="minPoolSize" value="${pool.minPoolSize}" ></property>
    <property name="maxPoolSize" value="${pool.maxPoolSize}" ></property>
    <property name="maxIdleTime" value="${pool.maxIdleTime}" ></property>
    <property name="acquireIncrement" value="${pool.acquireIncrement}" ></property>
    <property name="checkoutTimeout" value="${pool.checkoutTimeout}" ></property>
    <property name="maxIdleTimeExcessConnections" value="${pool.maxIdleTimeExcessConnections}" ></property>
</bean>    
<bean id="slave01DataSource" class="com.mchange.v2.c3p0.ComboPooledDataSource"
    destroy-method="close">
    <property name="driverClass" value="${jdbc.driver}" ></property>
    <property name="jdbcUrl" value="jdbc:mysql://127.0.0.1:3306/club?useUnicode=true&characterEncoding=UTF-8" ></property>
    <property name="user" value="${jdbc.username}" ></property>
    <property name="password" value="${jdbc.password}" ></property>
    <property name="initialPoolSize" value="${pool.initialPoolSize}" ></property>
    <property name="minPoolSize" value="${pool.minPoolSize}" ></property>
    <property name="maxPoolSize" value="${pool.maxPoolSize}" ></property>
    <property name="maxIdleTime" value="${pool.maxIdleTime}" ></property>
    <property name="acquireIncrement" value="${pool.acquireIncrement}" ></property>
    <property name="checkoutTimeout" value="${pool.checkoutTimeout}" ></property>
    <property name="maxIdleTimeExcessConnections" value="${pool.maxIdleTimeExcessConnections}" ></property>
</bean>    
<bean id="dataSource" class="com.mycompany.club.datasource.RWDataSource">
   <!-- 配置主库 -->
   <property name="master" ref="masterDataSource"></property>
   <!-- 配置从库列表 -->
   <property name="slaves">
       <map key-type="java.lang.String">
           <entry key="slave01DataSource" value-ref="slave01DataSource"></entry>
       </map>
   </property>
</bean>
<!-- MyBatis配置 -->
<bean id="sqlSessionFactory" class="org.mybatis.spring.SqlSessionFactoryBean">
    <property name="dataSource" ref="dataSource" ></property>
    <!-- 自动扫描entity目录, 省掉Configuration.xml里的手工配置 -->
    <property name="typeAliasesPackage" value="com.mycompany.club.entity" ></property>
    <!-- 显式指定Mapper文件位置 -->
    <property name="mapperLocations" value="classpath:/mapper/*Mapper.xml"></property>
    <property name="plugins">
        <list>
            <!-- 插件会按照配置的从下往上的顺序执行 -->    
            <bean class="com.mycompany.club.interceptor.RWInterceptor"></bean>
        </list>
    </property>
</bean>
<bean id="transactionManager" class="com.mycompany.club.datasource.RWTransactionManager">
    <property name="dataSource" ref="dataSource" ></property>
</bean>
<!-- 使用annotation定义事务 -->
<tx:annotation-driven transaction-manager="transactionManager" proxy-target-class="true" ></tx:annotation-driven>
<!-- 定义aspectj -->
<aop:aspectj-autoproxy proxy-target-class="true"></aop:aspectj-autoproxy>

2、
默认情况下，查询会从从库查询，修改、删除、插入会走主库；
可以在service方法上增加注解 @RWSource(DBType.SLAVE)来指定主库或从库；
如果service方法上有事务注解@Transactional则会走主库