[LANG-997] NumberUtil#isNumber() returns false for "012345678" but not for "12345678"

• Type: Bug
• Status: Closed
• Priority: Major
• Resolution: Not A Problem
• Affects Version/s: 3.3.2
• Component/s: lang.math.*

Environment

Java 6

• Assignee: Unassigned
• Reporter: Juan Pablo Santos Rodríguez
• Created: 21/Apr/14 14:27
• Updated: 28/May/16 16:22
• Resolved: 02/Jun/14 19:08

Description

With commons-lang 3.2.1:

boolean ret = NumberUtils.isNumber( "012345678901234567" );

returns true, but for 3.3.2, returns false.

The change seems to be introduced in LANG-972 / LANG-992, as it seems to consider now that, if the parameter string has a leading 0, and it's not hex, then it must be forcibly octal.

As previous 3.x versions accept 0ddd as valid decimal numbers, the suggested change on NumberUtils#isNumber, is to replace lines 1367-1376 with:

           } else if (Character.isDigit(chars[start + 1])) {
               // leading 0, but not hex, must be octal or decimal
               int i = start + 1;
               for (; i < chars.length; i++) {
                   if (chars[i] < '0' || chars[i] > '9') { // was: if (chars[i] < '0' || chars[i] > '7') {
                       return false;
                   }
               }
               return true; 
           }

Issue Links

• is broken by: LANG-971 NumberUtils#isNumber(String) fails to reject invalid Octal numbers
• is related to: LANG-1016 NumberUtils#isParsable method(s)
• relates to: LANG-972 NumberUtils#isNumber does not allow for hex 0XABCD
• relates to: LANG-992 NumberUtils#isNumber() returns false for "0.0", "0.4790", et al