Personally, I found the predicates variant more in...

2011-12-23T23:26:31.987+01:00

Personally, I found the predicates variant more intimidating and it required more concentration to cope with.

In any case, there is an excellent opportunity for you to empirically evaluate which version is more maintainable: I found a bug that was present in both implementations.

As I understand your description, the following test case should pass:

assertFalse(isCodeAllowed("###########"));

(I suspected that this was present based on the implementation of both isCodeAllowed methods)

You could use this as an opportunity for comparing how long it takes to fix a bug in either version, which is a good proxy for "goodness" in this case.

You might get some mileage out of CharMatcher for ...

2011-12-23T11:43:21.468+01:00

You might get some mileage out of CharMatcher for this particular task. I wonder if there's a Predicate wrapper that tests if a CharMatcher matches all characters in a string.

Comments on Thomas Ferris Nicolaisen's blog: Google Guava's Predicates

Personally, I found the predicates variant more in...

You might get some mileage out of CharMatcher for ...