Not sure I understand what you are doing, so I will just throw out some ideas.
If you want to different components to share the same data, then this can be done by sharing the "model" of the component. In the case of a JTextField you can share the Document:
Using this approach you don't need a listener or any kind. Since the text fields share the same Document, the same text will always be displayed in each text field.
If you want to know when the text is changed in either text field then you add a listener to the Document. Read the section from the Swing tutorial on
How to Write a DocumentListener for more information and examples.