MaskFormatter is used to format and edit strings. The behavior of a MaskFormat is controlled by way of a String mask that specifies the valid characters that can be contained at a particular location. The following characters can be specified:

Character	Description
#	Any valid number, uses Character.isDigit.
'	Escape character, used to escape any of the special formatting characters.
U	Any character (Character.isLetter). All lowercase letters are mapped to upper case.
L	Any character (Character.isLetter). All upper case letters are mapped to lower case.
A	Any character or number (Character.isLetter or Character.isDigit)
?	Any character (Character.isLetter).
*	Anything.
H	Any hex character (0-9, a-f or A-F).