Have you tried doing validation the way it's shown on the official Struts 2 documentation wiki?
(Although the code shown at the link seems okay from a quick glance; are you certain you've put the files in the correct places?) If you're having a problem with a third party's code, though, your best bet is to ask *them*. If you're having a specific issue with *your* code and/or configuration then you need to post it.
I have a registration page known as student registration.
there are few autocompleter fields like country dropdown, state drop down etc.
I am using struts2 validator to validate that none of the fields should be blank. If any field is blank it comes back to same page and displays the message in red that the particular field is required.
now the problem is when it comes back on same page incase of blank field the dropdowns are not working. Autocompleter is not generating the list.