Struts2 and form validation of prefilled forms

I'm using the validate() - method of struts2 to validate the form input. In my struts.xml I can define a result with name "input" which is displayed if the validation fails. This for the context :-)

Now my qu开发者_运维问答estion: the form I want to validate contains a selectbox which is filled out of a database. The first time the form is displayed everything works fine. But if I validate the form and the "input" - result is displayed, I get an IOException because of the iterator which outputs the db-result into my selectbox. Is there a solution from struts2 or do I have to use a plugin or something like that? Thank you!

When validation fails, it's often necessary to "reload" data for the form page. There's a FAQ entry that covers repopulating controls after validation, mainly detailing the Preparable interface (preferred) and the use of the <s:action> tag (there are some subtle gotchas that can pop up with this, but in general, it's also okay).