This week's book giveaways are in the Refactoring and Agile forums. We're giving away four copies each of Re-engineering Legacy Software and Docker in Action and have the authors on-line! See this thread and this one for details.
Abstract Classes vs. Interfaces It may also be instructive to look at real-life implementations, for example, the Java Collections Framework, which makes good use of both interfaces and abstract classes. [ September 09, 2008: Message edited by: Joe Ess ]