In a typical implementation of the Observer design pattern, you might want to have a Subject type and an Observer type. Here’s a code snippet that illustrates this.

The template method design pattern allows you to define the skeleton of an algorithm in a base class and defer the details to subclasses ...

EJB Design Patterns goes beyond high-level design pattern descriptions into critical EJB-specific implementation issues, illustrated with source code implementations. The book contains a catalog of ...