OTP generator return 5 digits instead of 6

[majaode]

Sometimes generateOneTimePassword returns 5 digits instead of 6. Not sure how to reproduce this

[jchambers]

generateOneTimePassword returns an int, and an int doesn't have any built-in notion of "number of digits." If you were to do this:

final int example = 12;
System.out.println(example);

…then you'd expect the output to be "12" and not "000012," right? The same thing is true with one-time passwords. When you generate a (six-digit) one-time password, you could wind up with a value anywhere between 0 and 999,999. If that value is 12, System.out.println(oneTimePassword) will just print "12."

What you need to do is:

System.out.format("%06d\n", oneTimePassword);

…or:

final String oneTimePasswordString = String.format("%06d", oneTimePassword);