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>

Related Content you might be interested in

Current Title:

Small book image
Learning Jakarta Struts 1.2: a concise and practical tutorial
Stephan Wiesner
Aug, 2005 | 220 pages
No titles found
Table of Contents (20 chapters)
Learning Jakarta Struts 1.2
Learning Jakarta Struts 1.2
Credits
Credits
Preface
Preface
About the Book
About the Book
Free Chapter
1
Introduction to Struts
Introduction to Struts
1.1 The Apache Jakarta Project
1.2 The Struts Project
1.3 The Struts Framework
1.4 Model Classes
1.5 Design Patterns
1.6 The Model View Controller (MVC)
1.7 MVC versus Model 2
1.8 Controller Component: ActionServlet
1.9 Design Guidelines for Action Classes
1.10 Reflection, Introspection, and DynaBeans
1.11 Session
1.12 Business Logic
1.13 Threads
1.14 Expandability
1.15 Debugging Struts Applications
1.16 Some Experiences
Summary
2
Hello Struts
Hello Struts
2.1 Tomcat Server Installation
2.2 Installation of Struts
2.3 A Simple Page
2.4 Internationalization with Struts
Summary
3
The Struts Shop
The Struts Shop
3.1 Why a Bookstore
3.2 Iterations
3.3 Elements of the Shop
3.4 Installing MySQL
3.5 Tables
Summary
4
Internationalization and Taglibs
Internationalization and Taglibs
4.1 The Structure for the Shop
4.2 Internationalization
4.3 The Welcome Page for the Shop
4.4 Custom Actions
4.5 struts-bean.tld
Summary
5
Logging and Configuration
Logging and Configuration
5.1 Configuration
5.2 Simple Logging
5.3 Logging Solutions
5.4 JDK Logging
5.5 Reading Configuration Settings
5.6 Logging with Log4J
5.7 Jakarta Commons Logging
5.8 Deciding What to Log
Summary
6
Forms
Forms
6.1 Preparation
6.2 Struts Form Beans
6.3 Database
Summary
7
Logic
Logic
7.1 Value Comparison
7.2 Substring Matching
7.3 Redirection
7.4 Collection Utilities
7.5 Sorting Tags
Summary
8
Exceptions
Exceptions
8.1 Tomcat Error Pages
8.2 Custom Exceptions
8.3 Exception Handling
8.4 ActionErrors
Summary
9
Controller and Templates
Controller and Templates
9.1 Consistent Layout without Struts
9.2 Central Controller with Struts
9.3 Consistent Layout with Struts Tiles
Summary
10
Putting It All Together
Putting It All Together
10.1 Authorization
10.2 BookCatalog
10.3 Price Information
10.4 The Shopping Cart
Exercise 4
10.5 Using the Shopping Cart
10.6 Placing Orders
Summary
11
Struts Validator and Plug-In Classes
Struts Validator and Plug-In Classes
11.1 Verifying User Input with the Struts Validator
11.2 Plug-In Classes
Summary
12
JSTL
JSTL
12.1 Installation
12.2 Internationalization
12.3 Java Classes
12.4 Iteration
12.5 JSTL and Struts-EL
Summary
13
Tools and Tricks
Tools and Tricks
13.1 Code Conventions
13.2 The Struts Console
13.3 Struts in WSAD (Eclipse)
13.4 StrutsDoc and Ant
13.5 Display Tags
13.6 Workflow
13.7 Testing: HTTPUnit
13.8 Different Struts Functions
13.9 XSLT Configuration Overview
13.10 Extending ActionServlet
Summary
Solutions
Solutions
Chapter 2: Hello Struts
Chapter 3: The Struts Shop
Chapter 4: Internationalization and Taglibs
Chapter 5: Logging and Configuration
Chapter 6: Forms
Chapter 7: Logic
Chapter 9: Controller and Templates
Chapter 10: Putting it All Together
Chapter 12: JSTL
Glossary
Glossary
Literature
Literature

8.4 ActionErrors

An encapsulation of an individual error message returned by the validate() method of an ActionForm,

Struts API

You have already used ActionErrors: 

ActionErrors errors = new ActionErrors();
if ((author.getFirstname() == null) || (author.getFirstname().length() < 3))
{
errors.add("firstname", new ActionError("error.author.firstname"));
}
<html:errors property="author.id"/>

So far, we have placed the text in the validate() method, but we can create ActionErrors from the Action class as well. The question is, how do we process it further. We could simply create an ActionErrors object and store it in the session, where it can be obtained and further processed as necessary. We can also store it in the following way:

Listing 8.9: saveErrors()
ActionErrors errors = new ActionErrors();
errors.add("myError", new ActionError("error.author.firstname"));
errors.add(ActionErrors.GLOBAL_ERROR,
new ActionError("error.author.lastname"));
saveErrors(req, errors);

Error values that...

Previous Section
End of Section 5
Next Section