How to maximize frame or window in Java (JFrame)

There are multiple ways but I recommend these lines of code:
        GraphicsEnvironment e = GraphicsEnvironment.getLocalGraphicsEnvironment();
        Frame fr= new Frame();
        fr.setMaximizedBounds(e.getMaximumWindowBounds());
        fr.setExtendedState(main.getExtendedState() | JFrame.MAXIMIZED_BOTH);
        fr.setVisible(true);

The code above will maximize your frame/window without hiding the taskbar (at the bottom part) in your screen except if you used undecorated frame. Any maximizing will hide your taskbar. This is according to my own experience but if you found ways to against it, please post it as  a comment. Thanks :)