Java Collections Framework (JCF) implements the Abstract Data Type for Java platform. Every serious Java programmer should familiar himself on this topic and be able to choose the right class for a specific need. A thorough introduction to JCF is not the target of this small article and to achieve that goal you can start with this excellent tutorial .
Instead, I'd like to
1) Provide an overview of JCF's classes,
2) Provide a cheat sheet you can post in your cubicle for daily reference,
3) Underline the relationship between JCF's implementation and the data structure and algorithm you learned in your undergraduate course
With these goals in mind, I came up following diagram - Java Collection Cheat Sheet. You can click it to zoom in. There is no necessity for more explanation once you're familiar with UML class diagram and have a basic understanding of common data structures.