I have a program I want to make into a jar file, so I did that with bluej, and the jar's size is very large, like 400MB. Not even Windows is that big.
One of my friends told me that I can create it with Eclipse, and it would be smaller. But I don't know if that's actually practical, since there's not that much info on it when you Google it (thus conclusion, there's a better way to do it).
Currently I'm trying trying that though, maybe I'll get it to work. But in the meantime if there is a better way, would someone point me in the right direction?
The command-line jar tool is very easy to use, and you can control exactly what goes into your file. Here is the page in the Java Tutorial describing the basics of using it. It's embedded in a larger tutorial about the many additional subtleties you might need to consider.