Is it possible to hide Netbeans title bar like Firefox in Gnom 3?

Solution 1:

No, it is not. Netbeans, and all Java applications that use Swing toolkit draw their widgets on their own, without guidance from window manager (as is the case with Qt or GTK). So, you can not hide parts of the GUI, change fonts or colors, automate clicks and so on, unless the application directly supports it, which Netbeans, I think, do not. This is one of the reasons people dislike Swing.