192. Design Patterns in Java Software

Rev. 5.0

 

This course is now available directly from our partner, Capstone Courseware.

This course seeks to develop, for the experienced Java programmer, a strong, shared vocabulary of design patterns and best practices.  The course begins with a discussion of how to recognize and apply design patterns – that is, how to incorporate pattern awareness into one’s own analysis, design, and implementation practices.  The main body of the course focuses on the Gang of Four design patterns, with a chapter each on creational, behavioral, and structural patterns.  Classroom time is about evenly split between discussion, group design exercises, and coding labs to reinforce finer points of important patterns.

 

This is not a patterns catalog: it is as much a study of how to “think in patterns” as it is an introduction to several of the most important patterns.  Students will be challenged to bring their own previous development experience to the discussion, to see the patterns in everyday design and coding solutions.  The course puts more emphasis on some patterns than others.  We believe that students will be better served by going into a few patterns in depth, with lively discussions of several others, than by following a regular routine of discussion and examples over every GoF pattern.

 

The course software also includes an optional overlay of workspace and project files to support use of the Eclipse IDE in the classroom.  (This requires that the instructor be experienced in use of Eclipse and able to walk students through basic tasks in the IDE.)

 

This revision of the course targets the 5.0 version of the Java language and Core API.  Students with Java 1.4 experience should find all of the concepts and most of the example and lab code accessible.  (A few examples that involve the Collections API are necessarily heavy on generic types, and this may require some additional support from the instructor.) 

 

LEARNING OBJECTIVES

 

·         Start to think in terms of design patterns.

·         Recognize and apply patterns to specific software development problems.

·         Use known patterns as a shared vocabulary in designing and discussing solutions.

·         Use Factories and Singletons to control object creation, for a variety of reasons.

·         Use Observers, Observables, and Model/View/Controller systems to decouple application behavior and preserve code scalability.

·         Understand the full motivation for the Command pattern and take advantage of Command frameworks in JFC.

·         Implement Adapters, rather than building redundant classes or creating intermediate data structures for consumption by existing code.

·         Understand and apply a range of other J2SE and J2EE patterns to improve code quality and scalability, and to produce high-quality solutions right off the bat.

 

Course Duration:  3 days.  (A 2-day timeline for non-programmers is also possible.)

 

Prerequisites: 

 

·         Solid Java programming experience is essential – especially object-oriented use of the language.  Language features and techniques that are integral to some lab exercises include interfaces and abstract classes, threading, generics and collections, and recursive methods.

·         Previous experience with UML (Unified Modeling Language) will be helpful, but is not critical.  The course uses UML class diagrams extensively but keeps notation fairly simple, and also includes a quick-reference appendix.

 

1. Recognizing and Applying Patterns

Design Patterns

Defining a Pattern

Unified Modeling Language

Seeing Patterns

Warning Signs and Pitfalls

 

2. Creational Patterns

Factory Patterns

The Singleton Pattern

APIs and Providers

Cascading Factories

 

3. Behavioral Patterns

The Strategy Pattern

The Template Method Pattern

The Observer Pattern

The Model/View/Controller Pattern

The Command Pattern

The Chain of Responsibility Pattern

 

4. Structural Patterns

The Composite Pattern

The Adapter Pattern

The Decorator Pattern

The Façade Pattern

The Flyweight Pattern

 

5. J2EE Patterns (Optional)

Model/View/Controller, Redux

The Intercepting Filter Pattern

The Front and Application Controller Patterns

The Business Delegate Pattern

The Service Locator Pattern

The Transfer Object Pattern

The Composite Entity Pattern

The Data Access Object Pattern

 

Appendix A.  Learning Resources

Appendix B.  UML Quick Reference

 

System Requirements

 

Hardware – minimal:                     Pentium 500MHz, 256 meg RAM, 500 meg HD.

Hardware – recommended:           Pentium 1.5gHz, 512 meg RAM, 1 gig HD.

 

Operating system:                          Tested on Windows XP Professional.  The course software should be viable on all Windows or Linux systems which support a J2SE 5.0 JDK.

 

Software:                                       All free downloadable tools.