context:property-placeholde

spring配置文件中添加：

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

或者

<bean id="propertyPlaceholderConfigurer" class="org.springframework,beans.factory.config.PropertyPlaceholderConfigurer">
    <property name="locations">
        <list>
            <value>jdbc.properties<value/>
        </list>
    </property>
</bean>