多链接池动态数据源的配置

<?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:aop="http://www.springframework.org/schema/aop"
 xmlns:tx="http://www.springframework.org/schema/tx"
 xsi:schemaLocation="
       http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans-2.5.xsd
       http://www.springframework.org/schema/tx http://www.springframework.org/schema/tx/spring-tx-2.5.xsd
       http://www.springframework.org/schema/aop http://www.springframework.org/schema/aop/spring-aop-2.5.xsd">
 <bean id="dataSourceA"  parent="parentDataSource">
 <property name="user" value="root"></property>
  <property name="password" value="123456"></property>
  <property name="jdbcUrl"
   value="jdbc:mysql://localhost:3306/u5_cn?useUnicode=true&amp;characterEncoding=utf-8"></property>
 </bean>
 <bean id="dataSourceB"  parent="parentDataSource">
  <property name="jdbcUrl"
   value="jdbc:mysql:/localhost:3306/szdc?useUnicode=true&amp;characterEncoding=utf-8"></property>
  <property name="user" value="root"></property>
  <property name="password" value="123456"></property>
 </bean>
 <bean id="parentDataSource" class="com.mchange.v2.c3p0.ComboPooledDataSource">
  <property name="driverClass" value="com.mysql.jdbc.Driver">
  </property>
  <!--
   <property name="jdbcUrl"    220.231.143.237   
   value="jdbc:mysql://localhost:3306/u5_cn?useUnicode=true&amp;characterEncoding=utf-8"></property>
   <property name="user" value="root"></property> <property
   name="password" value="123456"></property>
  --><!--连接池中保留的最小连接数。-->
  <property name="minPoolSize">
   <value>5</value>
  </property>
  <!--连接池中保留的最大连接数。Default: 15 -->
  <property name="maxPoolSize">
   <value>30</value>
  </property>
  <!--初始化时获取的连接数，取值应在minPoolSize与maxPoolSize之间。Default: 3 -->
  <property name="initialPoolSize">
   <value>10</value>
  </property>
  <!--最大空闲时间,60秒内未使用则连接被丢弃。若为0则永不丢弃。Default: 0 -->
  <property name="maxIdleTime">
   <value>60</value>
  </property>
  <!--当连接池中的连接耗尽的时候c3p0一次同时获取的连接数。Default: 3 -->
  <property name="acquireIncrement">
   <value>5</value>
  </property>
  <!--
   JDBC的标准参数，用以控制数据源内加载的PreparedStatements数量。但由于预缓存的statements
   属于单个connection而不是整个连接池。所以设置这个参数需要考虑到多方面的因素。
   如果maxStatements与maxStatementsPerConnection均为0，则缓存被关闭。Default: 0
  -->
  <property name="maxStatements">
   <value>0</value>
  </property>
  <!--每60秒检查所有连接池中的空闲连接。Default: 0 -->
  <property name="idleConnectionTestPeriod">
   <value>60</value>
  </property>
  <!--定义在从数据库获取新连接失败后重复尝试的次数。Default: 30 -->
  <property name="acquireRetryAttempts">
   <value>30</value>
  </property>
  <!--
   获取连接失败将会引起所有等待连接池来获取连接的线程抛出异常。但是数据源仍有效
   保留，并在下次调用getConnection()的时候继续尝试获取连接。如果设为true，那么在尝试
   获取连接失败后该数据源将申明已断开并永久关闭。Default: false
  -->
  <property name="breakAfterAcquireFailure">
   <value>true</value>
  </property>
  <!--
   因性能消耗大请只在需要的时候使用它。如果设为true那么在每个connection提交的
   时候都将校验其有效性。建议使用idleConnectionTestPeriod或automaticTestTable
   等方法来提升连接测试的性能。Default: false
  -->
  <property name="testConnectionOnCheckout">
   <value>false</value>
  </property>
 </bean>
 <!--动态数据源-->
 <bean class="com.iksns.u5.DynamicDataSource" id="dataSource">
  <property name="targetDataSources">
   <map key-type="java.lang.String">
    <entry key="a" value-ref="dataSourceA"></entry>
    <entry key="b" value-ref="dataSourceB"></entry>
   </map>
  </property>
  <property name="defaultTargetDataSource" ref="dataSourceA"></property>
 </bean>
 <bean id="sessionFactory"
  class="org.springframework.orm.hibernate3.LocalSessionFactoryBean">
  <property name="dataSource">
   <ref bean="dataSource" />
  </property>
  <property name="hibernateProperties">
   <props>
    <prop key="hibernate.dialect">
     org.hibernate.dialect.MySQLInnoDBDialect
    </prop>
    <prop key="hibernate.show_sql">true</prop>
    <prop key="hibernate.generate_statistics">true</prop>
    <prop key="hibernate.connection.release_mode">auto</prop>
    <prop key="hibernate.autoReconnect">true</prop>
   </props>
  </property>
  <property name="mappingResources">
   <list>

   </list>
  </property>
 </bean>

 

DynamicDataSource 继承 AbstractRoutingDataSource

具体代码

public class DynamicDataSource extends AbstractRoutingDataSource
{

 @Override
 protected Object determineCurrentLookupKey() {
  // TODO Auto-generated method stub
  return CustomerContextHolder.getCustomerType();
 }
 
}

 

public class CustomerContextHolder {
  private static final ThreadLocal<String> contextHolder = new ThreadLocal<String>();  
  
     public static void setCustomerType(String customerType) {  
         contextHolder.set(customerType);  
     }  
  
     public static String getCustomerType() {  
         return (String) contextHolder.get();  
     }  
  
     public static void clearCustomerType() {  
         contextHolder.remove();  
     }  
}