Frist of all, please be sure to use code tags when posting code to the forums. Unformatted or unindented code is extremely hard to read and many people that might be able to help you will just move along to posts that are easier to read. Please click this link ⇒ UseCodeTags ⇐ for more information. Properly indented and formatted code greatly increases the probability that your question will get quicker, better answers.
I've gone ahead and added the code tags for you. See how much easier the code is to read?
Secondly, you should not be using Java code in a JSP. That's a bad practice from 12 years ago! Do you not feel it is time to modernize? Please see this JspFaq entry.
Another point, correct terminology is important so that we all understand what's being talke about: HTM has no "combo box". Please see
What would be best is if you obtained the list for files to be displayed as options in the dropdown in the page controller and passed it to the JSP as a scoped variable. The in the JSP, you could use the JSTL and EL to iterate over the list and create option elements.