Runtime.exec could only work on the client side if run some kind of
applet *and* you know what programs are installed on the client.
Otherwise you will probably have to look into JavaScript, if it is possible at all.
Where exactly is the requirement coming from?
The soul is dyed the color of its thoughts. Think only on those things that are in line with your principles and can bear the light of day. The content of your character is your choice. Day by day, what you do is who you become. Your integrity is your destiny - it is the light that guides your way. - Heraclitus