spring .properties 配置文件

<bean id="conn" class="zc.factorybean.ConnectionFactoryBean">
     <property name="driverClassName">
       <value>${driverClassName}</value>
     </property>
     <property name="password">
       <value>${password}</value>
     </property>
     <property name="url">
       <value>${url}</value>
     </property>
     <property name="username">
        <value>${username}</value>
     </property>
  </bean>
  
  <bean id="propertyHolder" class="org.springframework.beans.factory.config.PropertyPlaceholderConfigurer">
    <property name="locations">
       <list>
          <value>/zc/adv/ph/jdbc.properties</value>
       </list>
    </property>
  </bean>