[Actionframework-users] org.actionframework.MissingParameterException

[<bm...@ho...>]

hi.
I have a form to upload files, the files are uploaded fine, but the problem
comes when the user submits the form with no file selected in the input
widget, I become the following error:

Conversion error occurred when handling action '/grabarGaleria' (field:
'miniatura'): org.actionframework.MissingParameterException: HTTP parameter
'miniatura' - taken from HTML <input> tag of type "File" - does not exist
(required by action '/grabarGaleria'); nested exception is:
org.actionframework.MissingParameterException: Parameter 'miniatura' is not
defined or the file has a zero length

I thought I could solve it using the on-exception in the xml config file:
inside the tag <action name="grabarGaleria" ... I put that code:
<on-exception class="org.actionframework.MissingParameterException"
show-template="uploadfile.vm" />
but the on-exception content isn't loaded altough ActionServlet checks
before if that exception does exist...

(I'm using ActionServlet 0.93.2c)

Thx in advance