How to create and modify jar files with an easy GUI tool?

Question

for example we have a jar file that use two library and these library's paths placed in class path in manifest, and we want to add new library to it path. at first i think editing manifest file as a text file and replace it is enough, but it's not the solution (!). i need a gui tool to do this task just work

Answer 1

Some of the GUI tools are IZArc or 7zip.

Answer 2

jar files are simply zip archives (with optional manifest added). You can use any zip manager e.g. 7zip.