When you create a new form (say “Swing.form”) the java file (“Swing.java”) is created automatically.
Refactoring those names, however, will not change the associated one. Refactor “Swing.form” to “New.form” and you still have “Swing.java” (not “New.java” that I would expect).
Alternatively, refactoring “Swing.java” to “New.java” leaves “Swing.form”, again not refactoring the associated file.
Chas Douglass