Thanks to everyone who pointed me to Commons Collections and its Functor package yesterday. To me, this is just one step below having closures natively present in the language. FYI, I was able to remove all duplication from my class and reduce the LOC from 211 to 136 – in other words, 75 lines of useless code GONE.
Here is what I did. First, I defined Predicates for each of my conditions. The simplest ones called a boolean method on the User object:
private final Predicate isX = new Predicate() { public boolean evaluate(Object object) { return ((User) object).isX(); }}
Only slightly more complicated ones checked to see if a given Collection was empty on the User object:
private final Predicate isX = new Predicate() { public boolean evaluate(Object object) { return CollectionUtils.isNotEmpty(((User) object).getItems()); }}
Next, I defined a method that would check the delegations for the User to see if any of them were an X:
boolean checkDelegations(User user, Predicate checkPredicate) { return CollectionUtils.exists(user.getDelegations(), checkPredicate);}
Finally, I implemented the security methods:
public boolean canDoThis() { return isX.evaluate(loggedInUser) || checkDelegations(loggedInUser, isX);}
Maybe it isn’t the most elegant or simplest of solutions, but it sure is a lot better than what I posted yesterday!
P.S. Since this is a Christian blog, I must remind you that RTFM stands for Read The FINE Manual!
