Predicate Logic

Q: Is there some easy way to chain predicates -- or do complex boolean logic. I would like to build a rule system based on the Predicate type but I dont like how the evaluate method takes an Object. I would rather have each Predicate be "setup" via some sort of interface PredicateContext (rather than Object) in the constructor (or factory method in this case).

A: The collections project provides a complete set of predicates including And and Or in the functor subpackage. However, for full functor based programming please consider using commons-functor at

Java 1.5 Support

Q: Does the collections project support any features of the new Java 1.5 language standard?

A: There is an unofficial release available at which adds type safety to all classes that don't break the Java collections interfaces. There are a couple outstanding decisions to be made on how to convert some of the classes which do violate an interface, but for the most part it should be ready for use.

Q: When will the commons-functor package "go live"?

Q: What About The Mysterious LRUMap NPE?

A: See CollectionsMysteriousNullPointerException

Collections_Questions (last edited 2009-09-20 23:48:35 by localhost)