有关Mysql分库分表，读写分离数据库水平拆分

web服务器一般都是一个服务器连接一个数据库的架构，可是随着系统的使用，该架构已经不能满足需求了，这里使用的是c3p0的数据库水平扩容。

Spring核心配置：

 <!-- 配置文件的引入 -->
   <bean id="propertyConfigurer" class="org.springframework.beans.factory.config.PropertyPlaceholderConfigurer">
       <property name="location">
         <value>classpath:/jdbc.properties</value>
       </property>
    </bean>

<!-- 配置三组数据源（每一组分主和从） -->
<!-- 数据源1 -->
    <bean id="dataSource1" class="com.mchange.v2.c3p0.ComboPooledDataSource">
        <property name="driverClass" value="${jdbc.driverClassName}" />
        <property name="jdbcUrl" value="${jdbc1.url}" />
        <property name="user" value="${jdbc1.username}" />
        <property name="password" value="${jdbc1.password}" />
        <property name="autoCommitOnClose" value="true"/>
<!--        <property name="checkoutTimeout" value="${cpool.checkoutTimeout}"/>-->
        <property name="initialPoolSize" value="${cpool.minPoolSize}"/>
        <property name="minPoolSize" value="${cpool.minPoolSize}"/>
        <property name="maxPoolSize" value="${cpool.maxPoolSize}"/>
        <property name="maxIdleTime" value="${cpool.maxIdleTime}"/>
        <property name="acquireIncrement" value="${cpool.acquireIncrement}"/>
        <property name="maxIdleTimeExcessConnections" value="${cpool.maxIdleTimeExcessConnections}"/>
    </bean>
    <!-- 数据源2 -->
        <bean id="dataSource2" class="com.mchange.v2.c3p0.ComboPooledDataSource">
        <property name="driverClass" value="${jdbc.driverClassName}" />
        <property name="jdbcUrl" value="${jdbc2.url}" />
        <property name="user" value="${jdbc2.username}" />
        <property name="password" value="${jdbc2.password}" />
        <property name="autoCommitOnClose" value="true"/>
<!--        <property name="checkoutTimeout" value="${cpool.checkoutTimeout}"/>-->
        <property name="initialPoolSize" value="${cpool.minPoolSize}"/>
        <property name="minPoolSize" value="${cpool.minPoolSize}"/>
        <property name="maxPoolSize" value="${cpool.maxPoolSize}"/>
        <property name="maxIdleTime" value="${cpool.maxIdleTime}"/>
        <property name="acquireIncrement" value="${cpool.acquireIncrement}"/>
        <property name="maxIdleTimeExcessConnections" value="${cpool.maxIdleTimeExcessConnections}"/>
    </bean>
    ...
    </bean>



<!-- 配置数据源 -->
    <bean id="dataSources" class="com.caland.sun.client.datasources.DefaultDataSourceService">
        <property name="dataSourceDescriptors">
            <set>
                <bean class="com.caland.sun.client.datasources.DataSourceDescriptor">
                    <property name="identity" value="partition1"/>
                    <!-- 指定数据源1 -->
                    <property name="targetDataSource" ref="dataSource1"/>
                    <!-- 对数据源1进行心跳监测 -->
                    <property name="targetDetectorDataSource" ref="dataSource1"/>
                    <!-- 指定备机数据源4 -->
                    <property name="standbyDataSource" ref="dataSource4"/>
                    <!-- 对备机进行心跳监测 -->
                    <property name="standbyDetectorDataSource" ref="dataSource4"/>
                </bean>
                <bean class="com.caland.sun.client.datasources.DataSourceDescriptor">
                    <property name="identity" value="partition2"/>
                    <property name="targetDataSource" ref="dataSource2"/>
                    <property name="targetDetectorDataSource" ref="dataSource2"/>
                    <property name="standbyDataSource" ref="dataSource5"/>
                    <property name="standbyDetectorDataSource" ref="dataSource5"/>
                </bean>
                <bean class="com.caland.sun.client.datasources.DataSourceDescriptor">
                    <property name="identity" value="partition3"/>
                    <property name="targetDataSource" ref="dataSource3"/>
                    <property name="targetDetectorDataSource" ref="dataSource3"/>
                    <property name="standbyDataSource" ref="dataSource6"/>
                    <property name="standbyDetectorDataSource" ref="dataSource6"/>
                </bean>
            </set>
        </property>
         <!-- HA配置，对数据库发送SQL语句：update caland set timeflag=CURRENT_TIMESTAMP()进行数据库状态检测 --> 
        <property name="haDataSourceCreator">
            <bean class="com.caland.sun.client.datasources.ha.FailoverHotSwapDataSourceCreator">
                <property name="detectingSql" value="update caland set timeflag=CURRENT_TIMESTAMP()"/>
            </bean>
        </property>
    </bean>

<!-- 配置路由规则开始 -->
    <!-- 该bean指定了路由算法的处理类 -->
    <bean id="hashFunction" class="com.caland.core.dao.router.HashFunction"/>
    <bean id="internalRouter"
        class="com.caland.sun.client.router.config.InteralRouterXmlFactoryBean">
        <!-- functionsMap是在使用自定义路由规则函数的时候使用 -->
        <property name="functionsMap">
            <map>
                <entry key="hash" value-ref="hashFunction"></entry>  指定使用哪个方法
            </map>
        </property>
        <property name="configLocations">  指定配置路由的xml路径
            <list>
                <value>classpath:/dbRule/sharding-rules-on-namespace.xml</value>
            </list>
        </property>
    </bean>
<!-- 配置路由规则结束 -->  

路由的配置文件
<rules>
  <rule>
        <namespace>User</namespace>
        <!-- 
               表达式如果不使用自定义路由规则函数,而是直接使用   taobaoId%2==0这种的话就不用在文件
               中配置<property name="functionsMap">中了
        -->
        <shardingExpression>hash.applyUser(username) == 1</shardingExpression>
        <shards>partition1</shards>
    </rule>
    <rule>
        <namespace>User</namespace>
        <shardingExpression>hash.applyUser(username) == 2</shardingExpression>
        <shards>partition2</shards>
    </rule>
    <rule>
        <namespace>User</namespace>
        <shardingExpression>hash.applyUser(username) == 3</shardingExpression>
        <shards>partition3</shards>
    </rule>
</rules>