springmvc的一些零碎知识点
用property-placeholder在同一个容器中导入两个不同properties文件，要注意添加ignore-unresolvable="true"属性，参考 http://aoyi.iteye.com/blog/1151757
如果上传的文件过多, 就直接用服务器的本地文件夹吧，例如：
在attachmentSetting.properties中定义了attachment.setting.ResidentPopulation_attachment=file:///D:/ResidentPopulation_attachment
applicationContext.xml 中定义了：
<context:property-placeholder location="classpath:attachmentSetting.properties" ignore-unresolvable="true"/>
<bean id="attachmentSettingResidentPopulationAttachment" class="java.lang.String">
<constructor-arg value="${attachment.setting.ResidentPopulation_attachment}"/>
</bean>
在java文件中给属性attachmentSettingResidentPopulationAttachment自动注入上面的String值，
只要new File(new URI(attachmentSettingResidentPopulationAttachment));就得到文件夹了，可以上传和维护了
applicationContext-servlet.xml中定义了
<context:property-placeholder location="classpath:attachmentSetting.properties" ignore-unresolvable="true"/>
<resources location="${attachment.setting.ResidentPopulation_attachment}" mapping="/ResidentPopulation_attachment/**"/>
可以方便下载 只要http://ip:port/project/ResidentPopulation_attachment/attachment.zip 就可以下载服务器 D:/ResidentPopulation_attachment下的attachment.zip 文件了
不同容器要使用同一properties文件中的内容，就各导入一次吧，上面的spring容器和servlet对应的spring子容器就各导入了一次attachmentSetting.properties文件