Java 7 application halting OSX when left unatteended

[Paul Taylor]

My (java 7 based) Gui application processes digital music files, and is 
designed so it can be left unattended. I have noticed that if I leave it 
running overnight on my OSX Mavericks computer that it stops shortly 
after I leave it, only continuing when I touch the keyboard in the morning.

How can I prevent this, I do not have the same problem running the 
application on a Windows 8 machine.

paul