[LANG] LANG-1252 - NumberUtils.isNumber and NumberUtils.createNumber resolve inconsistently

[Rob Tompkins]

In short, I’m trying to generalize LANG-1060, LANG-1040, LANG-1038, and 
LANG-992 with a single issue that actually hits all the bases here with 
NumberUtils.isNumber.

Bug (1):

        System.out.println(lang.math.NumberUtils.isNumber(“+2”)); ----> false

while
        
        System.out.println(lang.math.NumberUtils.createNumber(“+2)); ----> 2

Bug (2):


        System.out.println(lang.math.NumberUtils.isNumber(“01.5”)); ----> false

while
        
        System.out.println(lang.math.NumberUtils.createNumber(“01.5)); ----> 
1.5.



It seems to me that we could externalize a considerable amount of the code 
underlying the two methods into shared methods, as it seems like all the 
validations in createNumber that predicate object creation should be directly 
used in isNumber. I would love to hear folks’ thoughts.

Cheers,
-Rob