There is no standard method to password-protect a zip file. Each archigin utility that offers it would implement its own way. The most common one is probably WinZip's method, but even that is not universal. So - you're largely out on your own for this.
Joined: Jun 11, 2012
wonder anyone has faced and solved this problem before?
doesn't look like winzip has its own java library to password protect an existing zip file.