The road to successful web applications is paved with the sweat and heartache of the many who came before us. The idea of taking a rich client application and allowing it to execute over the Internet was a great leap of faith, and maybe just a little shortsighted. By "web applications," I don't mean small, trivial applications that accept a form or two of input and push it into a database; I mean large applications that cross several tiers, use many different technologies, and cover the spectrum of analysis and design-pattern uses.
The design and construction of these types of applications push developers to the limit of what's logically and physically possible. Myriad solutions have been thrown at the problems these applications present. Some of the solutions stuck, and some did not—and when a solution didn't serve the needs of the users, it was obvious. But as with human evolution, the valuable characteristics eventually were passed on, and the characteristics that failed to serve their intended purposes fell by the wayside.
The user interface (UI) in Smalltalk-80™ was designed around the Model-View-Controller (MVC) framework. Over time, this framework has been adopted as a classic design pattern and used in many different scenarios. Other UI frameworks, such as the one written for Java™ Swing, use similar concepts. The architects of the JavaServer Pages™ (JSP) specification formally introduced the abstract idea of two types of models for web-based solutions: Model 1 and Model 2. The distinguishing feature between the two is that Model 2 uses a separate component to handle the controller responsibilities. This allows JSP to focus exclusively on rendering the view while using JavaBeans™ as the model, thereby effectively becoming an abstract implementation of a web-based MVC architecture.
The Struts framework, created by Craig R. McClanahan and donated to the Apache Software Foundation (ASF) in 2000, is an open source implementation of Model 2 ideas. This book covers Version 1.1 of the Struts framework, but because backward compatibility was one of the design goals of 1.1, 1.0 Struts developers also will find value in reading this book.
If you learn one thing from this book, it should be that frameworks such as Struts are a great time investment. If you are building applications, web-based or not, you should be using at least one framework, and as web frameworks go, Struts is one of the best.