Book Image

Learning Jakarta Struts 1.2: a concise and practical tutorial

By : Stephan Wiesner
Book Image

Learning Jakarta Struts 1.2: a concise and practical tutorial

By: Stephan Wiesner

Overview of this book

<p>Jakarta Struts is an Open Source Java framework for developing web applications. By cleanly separating logic and presentation, Struts makes applications more manageable and maintainable.<br />Since its donation to the Apache Foundation&nbsp; in 2001, Struts has been rapidly accepted as the leading Java web application framework, and community support and development is well established.<br /><br />Struts-based web sites are built from the ground up to be easily modifiable and maintainable, and internationalization and flexibility of design are deeply rooted. Struts uses the Model-View-Controller design pattern to enforce a strict separation between processing logic and presentation logic, and enables efficient object re-use.<br /><br />The book is written as a structured tutorial, with each chapter building on the last. The book begins by introducing the architecture of a Struts application in terms of the Model-View-Controller pattern. Having explained how to install Jakarta and Struts, the book then goes straight into an initial implementation of the book store. The well structured code of the book store application is explained and related simply to the architectural issues.<br /><br />Custom Actions, internationalization and the possibilities offered by Taglibs are covered early to illustrate the power and flexibility inherent in the framework. The bookstore application is then enhanced in functionality and quality through the addition of logging and configuration data, and well-crafted forms. At each stage of enhancement, the design issues are laid out succinctly, then the practical implementation explained clearly. This combination of theory and practical example lays a solid understanding of both the principles and the practice of building Struts applications.</p>
Table of Contents (20 chapters)
Learning Jakarta Struts 1.2
Credits
Preface
About the Book
Glossary
Literature

5.1 Configuration


It is useful to bunch configuration values together in a single file (or at least in as few files as possible). This not only simplifies maintenance, but it also increases security because you know exactly which files to back up. In UNIX, you can provide higher security by assigning authorization rights for configuration files.

There is always a question as to which is the most elegant way to access the data. Naturally, you can read the files each time you need a value, but this does not lead to high performance, plus you will end up with a lot of redundant code this way. A Singleton Design Pattern (see Glossary) works well in most cases.

Create a new directory called WEB-INF/classes/tools. Create a class named PropertiesSingleton.java here and enter the code shown in Listing 5.1. This class originates from one of the open-source projects (http://sourceforge.net/projects/swiesnerxmlgui) and has been used in a lot of projects since.

The constructor is declared private so that...