Is it possible to add a character or a String after the value in a
Check out the section from the Swing tutorial on Specifiying Spinner Formatting.
The default editor of the spinner is a
JFormattedTextField. So you can access this and set your own formatting.
If you have never used a JFormattedTextField before then the tutorial also has a section on
How to Use Formatted Text Fields to help you in creating the mask you want to use.