Can I implement a toolbar/dock in Java?

Hallo,
I'd like to know if it is somehow possible to implement a toolbar/dock
in pure Java (or with an existing open source library that supports at
least Windows an Linux)?
The problem I have is that I can see no way of reserving screen space
in a way that will make other windows that are NOT part of my
application stay clear of this space when maximizing. There is
unfortunately no java.awt.Toolkit.setScreenInsets().
Does anyone have an idea how to do this or is this just not possible in
Java?

Ciao

Matthias

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