A good answer might be:

JTextField Class Hierarchy

It is part of the Swing package, so is defined in javax.swing.. Here is how it fits into the class hierarchy. The lavender clouds are part of Swing.

JTextField derives from javax.swing.JTextComponent. JTextComponent is a feature-rich component that supports nearly all the features of a text editor. The user can edit text as it is entered (using the backspace, delete, and arrow keys), drag and drop text, and work with the clipboard.

QUESTION 3:

To investigate the full set of features for JTextComponent where should you look?