upload.parseRequest(request);为空,问题解决！
upload.parseRequest(request);用到strut2 在网上找了，说是struts2 把request 给拦截了，所以就
upload.parseRequest(request)为null.
网上大多方法是将web.xml配置修改如下：（而我的问题是，修改后,web 就不能运行了，）
<filter>
<filter-name>struts2</filter-name>
<filter-class>
org.apache.struts2.dispatcher.ng.filter.StrutsPrepareAndExecuteFilter
</filter-class>
</filter>
<filter-mapping>
<filter-name>struts2</filter-name>
<url-pattern>/*</url-pattern>
</filter-mapping>
-----------
改为
<filter-mapping>
<filter-name>struts2</filter-name>
<url-pattern>*.action</url-pattern>
</filter-mapping>
后，程序就不能运行了。
提示
The Struts dispatcher cannot be found.
--------------------编程问答-------------------- 如果改为
<filter-mapping>
<filter-name>struts2</filter-name>
<url-pattern>/*.action</url-pattern>
</filter-mapping>
也是一样的。则会404错误
HTTP Status 404 -
type Status report
message
description The requested resource () is not available.
--------------------编程问答--------------------
补充：Java , Java相关
