Executing terminal commands in my Java application.

Is it possible to execute terminal commands through a java program? I.E. make a program that runs a line of code in ther terminal to change system prefernces? or even simpl things like changeing dircetory and making folders,

I need to do this for mac (unix), but any info for windows(ms-dos) would be appriciated aswell.

[333 byte] By [coryw68122a] at [2007-10-3 4:03:32]