A DESCRIPTION OF THE PROBLEM :
public static unsigned long id;

Reasons:
It's difficult to make a java app to decode an unkown file type without having unsigned bytes on binary files
People want values that are greater then current short max value but, not quite int
People want ids that are greater then long max value but are not strings to take up less bytes
People want values greater then int max value but, less then long max value
File readings on all primitive types because a byte might have to be combined with other bytes for manipulating data on binary files