Passing information about UI objects to a java agent

The lotus java agents don’t have classes to manage the UI objects, such as in LotusScript with the classes NotesUIDocument or NotesUIView.
It’s true that you can find several info about the Notes Client Java UI API in internet, but these classes are not officially supported.
In this post I explain 3 ways to obtain the currently open view or document inside an agent java.
You take advantage of the LotusScript UI classes that can easily manage the UI objects, and you pass them to the java agent using the variables in the notes.ini or a profile document or a notes document.