复制多份，保证有效的配置文件，属性时true就行

<bean class="org.springframework.beans.factory.config.PropertyPlaceholderConfigurer">
<property name="locations">
<list>
<value>classpath*:redis.properties</value>
</list>
</property>
<property name="ignoreUnresolvablePlaceholders" value="http://www.mamicode.com/true" />
</bean>

spring 配置多个properties