Java collections brain teasers

Question

Java collections are invaluable tool in exchanging data between database and service layer. We have various cases of a HashMap, ArrayList, a HashMap of arraylists etc.

I'm looking for programming samples, that contain a lot of exercise from simple to complex to deal with collections. It need not have answers/sample codes, just a variety of difficult questions would be enough.

Anyone know of any such website?

Answer 1

Official Java Collections Tutorial

Answer 2

I'm not sure this is very complex (it's meant to serve as interview questions), but it's a decent collection of questions on collections (I've used it in the past when interviewing people for developers positions).. : http://www.interview-questions-java.com/java-collections.htm .

Answer 3

The Java Developers Almanac.

Answer 4

Java Data Structures