You can always replace your application's libraries without having to restart the server. Looks like the ANT command is not able to copy the library properly to the appropriate location(since this file is already in use) and as a result you are seeing the ZipException. Just try replacing the library manually and see if it works.
You can place your jar file in your application path,that is,you should copy jar files to the .ear package.
First of all, thanks for your answers - I really appreciate your help.
- Deleting the libs manually or via Ant is denied
- Replacing them manually leads to the same result as via Ant
- My application doesn't resides in a .sar but in a .war package. That's where I copy the libs into. Does that make any difference?
I haven't found the problem yet but it seams to me as if the libs I want to replace are in fact buggy. Replacing other ones on-the-fly seems to works. I hope to find the bug in my application code...
Thanks for your time.