zipping or not

hello all,
in my program I want to parse several flatfiles. Depending on the source (where these files come from originally) a parsing procedure can involve only a single file, or several files (different or same format), or a zipfile with several files (different or same format).
My problem is that I don't want to bother the parser with the I/O stuff - check for the existence of the files, open the streams. In some cases one InputStream would be sufficient, in other cases I seem to need several, and in case of a zipfile I would need a ZipInputStream, or I would need to uncompress the file first.
Now, I had a new idea: what if the program zips all the sourcefiles to appropriate bundles - depending on the source target. Thus, the different parsers would all get just a ZipInputStream. Sure, then they will have to bother with uncompressing, but at least the existence of the files would have been checked before.
Am I totally misguided by this idea? Does the extra compressing mean a big overhead in performance, or would it even gain some time? (At the moment the files are located inside the unix file system or at least in a mounted fs tree where the program will run.)
Any comments on the idea or new suggestions

would be very welcome!
Thank you
Chantal

Your idea is logical and clear, but for perfomance issues... i don't know.
Napa