spring+hibernate下连接两个以上的数据库

新的系统有可能会要用到遗留系统的数据，所以有时就会要连接两个以上的数据库。
那么怎么来处理这一问题呢？
原理：创建类似的文件（两个数据库就有两个类似用spring+hibernate的配置文件）
下面以webwork+spring+hibernate来说明。
1）web.xml

<?xml version="1.0" encoding="UTF-8"?>
<web-app xmlns="http://java.sun.com/xml/ns/j2ee"
    xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
    xsi:schemaLocation="http://java.sun.com/xml/ns/j2ee http://java.sun.com/xml/ns/j2ee/web-app_2_4.xsd" version="2.4">

    <display-name>shipment</display-name>

    <!-- Define the basename for a resource bundle for I18N -->
    <context-param>
        <param-name>javax.servlet.jsp.jstl.fmt.localizationContext</param-name>
        <param-value>messages</param-value>
    </context-param>
<!--加载spring+hibernate的配置文件-->
      <context-param>
        <param-name>contextConfigLocation</param-name>
        <param-value>
            /WEB-INF/applicationContext*.xml
            /WEB-INF/action-servlet.xml
        </param-value>
    </context-param>
<!-- 把webwork与spring结合起来-->
    <listener>
        <listener-class>org.springframework.web.context.ContextLoaderListener</listener-class>
    </listener>
    <listener>
        <listener-class>com.opensymphony.xwork.spring.SpringObjectFactoryListener</listener-class>
    </listener>
<!-- 所有的请求响应的类-->
    <servlet>
        <servlet-name>action</servlet-name>
        <servlet-class>com.opensymphony.webwork.dispatcher.ServletDispatcher</servlet-class>
        <load-on-startup>1</load-on-startup>
    </servlet>

      <servlet-mapping>
        <servlet-name>action</servlet-name>
        <url-pattern>*.html</url-pattern>
    </servlet-mapping>

    <welcome-file-list>
        <welcome-file>login.jsp</welcome-file>
    </welcome-file-list>

</web-app>

  2) xwork.xml用来配置action

<!DOCTYPE xwork PUBLIC "-//OpenSymphony Group//XWork 1.0//EN" 
"http://www.opensymphony.com/xwork/xwork-1.0.dtd">

<xwork>
      <!-- Include webwork defaults (from WebWork-2.1 JAR). -->
      <include file="webwork-default.xml"/>
      
      <!-- Configuration for the default package. -->
      <package name="default" extends="webwork-default">
        <interceptors>
            <!-- Interceptor to catch exceptions and display mapped exception result -->
            <interceptor name="exceptionHandler" class="exceptionInterceptor"/>
            <interceptor-stack name="defaultExceptionStack">
                <interceptor-ref name="defaultStack"/>
                <interceptor-ref name="exceptionHandler"/>
            </interceptor-stack>
        </interceptors>
        <!-- Default interceptor stack. --> 
        <default-interceptor-ref name="defaultExceptionStack"/> 
        
        <global-results> 
            <result name="dataAccessFailure">dataAccessFailure.jsp</result>
        </global-results> 
           <!--- shipment2 -->
          <action name = "login" class= "loginAction" method="login">
                     <result name="success" type ="dispatcher">shipmentv.jsp</result>
                     <result name="failuer" type="dispatcher">login.jsp</result>
           </action>
        </package>
</xwork>

       3)action-servlet.xml配置action与调用DAO

<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE beans PUBLIC "-//SPRING//DTD BEAN//EN"
    "http://www.springframework.org/dtd/spring-beans.dtd">

<beans>
    <bean id="loginAction" class="com.legend.shipment.web.LoginAction" singleton="false">
            <property name="shipmentManager" ref="shipmentManager"/>
     </bean>

</beans>

     4)applicationContext.xml配置事务管理　

<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE beans PUBLIC "-//SPRING//DTD BEAN//EN"
    "http://www.springframework.org/dtd/spring-beans.dtd">

<beans>
    <bean id="propertyConfigurer" class="org.springframework.beans.factory.config.PropertyPlaceholderConfigurer">
        <property name="location" value="classpath:jdbc.properties"/>
    </bean>

    <!-- Transaction template for Managers, from:
         http://blog.exis.com/colin/archives/2004/07/31/concise-transaction-definitions-spring-11/ -->
    <bean id="txProxyTemplate" abstract="true"
        class="org.springframework.transaction.interceptor.TransactionProxyFactoryBean">
        <property name="transactionManager"><ref bean="transactionManager"/></property>
        <property name="transactionAttributes">
            <props>
                <prop key="save*">PROPAGATION_REQUIRED</prop>
                <prop key="remove*">PROPAGATION_REQUIRED</prop>
                <prop key="*">PROPAGATION_REQUIRED,readOnly</prop>
            </props>
        </property>
    </bean>

    <bean id="shipmentManager" parent="txProxyTemplate">
        <property name="target">
            <bean class="com.legend.shipment.service.impl.ShipmentManagerImpl">
                <property name="shipmentDAO" ref="shipmentDAO"/>
            </bean>
        </property>
    </bean>
</beans>

         5)applicationContext-hibernate.xml配置hibernate

<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE beans PUBLIC "-//SPRING//DTD BEAN//EN"
    "http://www.springframework.org/dtd/spring-beans.dtd">

<beans>
    <bean id="dataSource" class="org.springframework.jdbc.datasource.DriverManagerDataSource">
        <property name="driverClassName" value="${jdbc.driverClassName}"/>
        <property name="url" value="${jdbc.url}"/>
        <property name="username" value="${jdbc.username}"/>
        <property name="password" value="${jdbc.password}"/>
    </bean>

    <bean id="sessionFactory" class="org.springframework.orm.hibernate3.LocalSessionFactoryBean">
        <property name="dataSource" ref="dataSource"/>
        <property name="mappingResources">
            <list>
                <value>com/legend/shipment/TworkCost.hbm.xml</value>
                <value>com/legend/shipment/TworkConfig.hbm.xml</value>
            </list>
        </property>
        <property name="hibernateProperties">
            <props>
                <prop key="hibernate.dialect">org.hibernate.dialect.SQLServerDialect</prop>
                <prop key="hibernate.show_sql">true</prop>
            </props>
        </property>
    </bean>

    <bean id="transactionManager" class="org.springframework.orm.hibernate3.HibernateTransactionManager">
        <property name="sessionFactory" ref="sessionFactory"/>
    </bean>

    <bean id="shipmentDAO" class="com.legend.shipment.dao.hibernate.ShipmentDAOHibernate">
        <property name="sessionFactory" ref="sessionFactory"/>
    </bean>
</beans>

       6)jdbc.properties数据库连接信息

jdbc.driverClassName=com.microsoft.jdbc.sqlserver.SQLServerDriver
jdbc.url=jdbc:microsoft:sqlserver://192.168.1.6:1433;DatabaseName=dg_labour;SelectMethod=cursor;
jdbc.username=sa
jdbc.password=test

　　如果要连接两个数据库的话，那么就加多一个类似applicationContext-hibernate.xml文件，一个类似applicationContext.xml的文件，并在jdbc.properties文件中添加另一个数据库的连接信息。当然要作小的修改。比如说：你在applicationContext-another.xml加了一个名为workManager的事务代理。你想把它添加到loginAction中去，那么就把action_server.xml文件修改成

<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE beans PUBLIC "-//SPRING//DTD BEAN//EN"
    "http://www.springframework.org/dtd/spring-beans.dtd">

<beans>
    <bean id="loginAction" class="com.legend.shipment.web.LoginAction" singleton="false">
            <property name="shipmentManager" ref="shipmentManager"/>
　　　　<property name="workManager" ref="workManager"/>　　　
     </bean>

</beans>

在java程序中就可以通过setWorkManager()方法自己设置了，也就可以在LoginAction类中引用了。
可能说的不够详细，但提供了一个思路。