OK, a bit of googling got me the API doc (second hit for me), and it contains right in the first sentence:
Deprecated. replaced by AboutHandler, PreferencesHandler, AppReOpenedListener, OpenFilesHandler, PrintFilesHandler, QuitHandler, QuitResponse.
(with links to the interfaces and class in mentioned).
So it looks like you should not use one object subclassing this abstract class, but several objects for the different purposes, and register them each with your Application object.
与恶龙缠斗过久,自身亦成为恶龙;凝视深渊过久,深渊将回以凝视…