If you want 2 in 1 I think it's going to be a moderate book. I think it's more important to have a book for understanding and as far as the APIs are concerned, you can find everything in Sun's site. An excellent book for understanding is Head First Java by Oreilly.
There aren't really any books on just java collections, but have a look at www.java.sun.com where there is a good section on the collections framework and the new 1.5 language specific additions and updates.
Originally posted by Muni K Reddy: Hello! Could anyone please recommend a good book for a comprehensive explanation of the Collection API, which could be used as a tutorial as well as a reference book.