spring配置多个属性文件

 <bean id="configRealm" class="org.springframework.beans.factory.config.PropertiesFactoryBean">         <property name="locations">            <list>                <value>classpath:conf/internal.properties</value>                <value>classpath:conf/jdbc.properties</value>                <value>classpath:conf/redis.properties</value>                <value>classpath:conf/session.properties</value>                                <value>classpath:conf/mongo.properties</value>            </list>        </property>    </bean>     <bean id="propertyConfigurer" class="org.springframework.beans.factory.config.PreferencesPlaceholderConfigurer">         <property name="properties" ref="configRealm"/>    </bean>