This is used when receiving the error information as an event generated in the formatting process.\.
This is used when receiving the formatted page number as an event generated in the formatting process
If the class that implements this interface is registered using the setFormatPageListener method, the page number from XfoObj can be received as the event
XfoObj Class is the object class of AH Formatter
This class is thrown by the method of XfoObj, and this class indicates the exception occurred in XfoObj.