AOP方式代码控制多数据源切换

要想控制多数据源,必须继承spring提供的一个接口类

重写里面AbstractRoutingDataSource的determineCurrentLookupKey()

这里需要返回Map<Object, Object> targetDataSources的 key,那么在spring配置一个bean吧,当然也可以写死,或者new 一个对象,但是spring还是推荐用配置.

注意,为什么会知道呢?也是百度和看了一下AbstractRoutingDataSource的源码的

那么就需要配置spring了如下,我这里配置一个主库和两个从库,

mysql怎么配置主从复制?上面一篇已经说明了

看下面配置spring-cfg.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"
       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-4.0.xsd
    http://www.springframework.org/schema/context
    http://www.springframework.org/schema/context/spring-context-4.0.xsd
    http://www.springframework.org/schema/tx
    http://www.springframework.org/schema/tx/spring-tx-4.0.xsd http://www.springframework.org/schema/aop http://www.springframework.org/schema/aop/spring-aop.xsd"
>

    <!--扫描注解生成bean-->
    <context:annotation-config/>
    <!--包扫描-->
    <context:component-scan base-package="com.*"/>

    <context:property-placeholder location="classpath:jdbc.properties"/>

    <bean id="sqlSessionFactory" class="org.mybatis.spring.SqlSessionFactoryBean">
        <property name="dataSource" ref="dataSource"/>
        <property name="mapperLocations" value="classpath:com/*/**/**.xml"/>
    </bean>

    <bean class="org.mybatis.spring.mapper.MapperScannerConfigurer">
        <property name="basePackage" value="com.*.*.dao"/>
        <property name="sqlSessionFactoryBeanName" value="sqlSessionFactory"/>
    </bean>

    <!--声明事务管理 采用注解方式-->
    <tx:annotation-driven transaction-manager="transactionManager"/>
    <bean id="transactionManager" class="org.springframework.jdbc.datasource.DataSourceTransactionManager">
        <property name="dataSource" ref="dataSource"/>
    </bean>
    <aop:aspectj-autoproxy/>

    <bean id="switchDataSourceAspect" class="com.*.common.DataSourceAspect"/>
    <aop:config>
        <aop:aspect ref="switchDataSourceAspect">
            <aop:pointcut id="tx" expression="execution(* com.*.*.service.*.*(..))"/>
            <aop:before method="before" pointcut-ref="tx"/>
        </aop:aspect>
    </aop:config>
    <!--数据库设置-->
    <bean id="masterdataSource" class="com.alibaba.druid.pool.DruidDataSource"
          destroy-method="close" init-method="init">
        <property name="url" value="${jdbc_url_m}"/>
        <property name="username" value="${jdbc_username}"/>
        <property name="password" value="${jdbc_password}"/>
    </bean>
    <bean id="slavedataSource_1" class="com.alibaba.druid.pool.DruidDataSource"
          destroy-method="close" init-method="init">
        <property name="url" value="${jdbc_url_s_1}"/>
        <property name="username" value="${jdbc_username}"/>
        <property name="password" value="${jdbc_password}"/>
    </bean>
    <bean id="slavedataSource_2" class="com.alibaba.druid.pool.DruidDataSource"
          destroy-method="close" init-method="init">
        <property name="url" value="${jdbc_url_s_2}"/>
        <property name="username" value="${jdbc_username}"/>
        <property name="password" value="${jdbc_password}"/>
    </bean>
    <bean id="dataSource" class="com.*.common.DynamicDataSource">
        <property name="targetDataSources">
            <map>
                <entry key="master" value-ref="masterdataSource"/>
                <entry key="slave_1" value-ref="slavedataSource_1"/>
                <entry key="slave_2" value-ref="slavedataSource_2"/>
            </map>
        </property>
        <property name="defaultTargetDataSource" ref="masterdataSource"/>
    </bean>


</beans>

如上面配置所示,首先三个数据源的配置分别为masterdataSource,slavedataSource_1,slavedataSource_2,其次就是配置datasource了,datasource额里面有两个属性targetdatasources 和 defaultTargetDataSource.

配置好了就可以通过AbstractRoutingDataSource的determineCurrentLookupKey()传入的key来控制用那个数据源.

源码地址https://github.com/1344115844/mysql-master-slave , clone自己看吧