“Three months, or you’re dead!”
These were the opening words of the keynote speaker at a conference I attended over what now seems a long time ago. Three months, the speaker’s argument went, was the time available to turn an idea into a fully realized solution. After that, the idea would be out of date and the competition ahead.
The specifics of the rest of the presentation have since faded from memory. The speaker went on to cover the intricacies of B2B and C2B for e-business, but by that stage, my thoughts were elsewhere. The point had been well made: The business world had embraced the Internet, and with it, a new unit of measure—Internet-time.
On reflection, the speaker’s opening remarks were something of a watershed in my approach to software engineering. Quality is fundamental to all projects. Nevertheless, the need to accommodate change quickly puts another watchword at the top of the list, alongside quality: rapidity!
Modern-day business continues to move at an ever-faster rate, and the enterprise systems that underpin those businesses are required to keep pace. As software professionals, we find ourselves under increasing pressure not only to deliver on quality but also within ever-decreasing time-frames. Compounding these demands further is a marked rise in system complexity. Gone are the days when a system’s boundaries were constrained to a single organization. The allure of the Internet for e-commerce has led to demands for systems that require integration on a truly global scale.
Meeting this demand is not easy. Indeed, it has never been easy. In his landmark article No Silver Bullet, Fredrick P. Brooks argued there would be no new breakthrough in software development technology that would result in even a single order of magnitude increase in productivity [Brooks, 1987]. Although published over a decade ago, Brooks’s statement still holds true. Despite this perceived inability to address the essential complexity of software development, the business world continues to make ever-increasing demands of software professionals despite the poor track record of the IT industry in delivering quality solutions to even medium-term timeframes. Further compounding the problem is the current climate of fierce competition between software vendors, who vie to outdo one another in a bid to win work in what is presently a high-risk market.
Therefore, the bar continues to rise for us as IT professionals. In order to keep pace with these steadily escalating demands and rising competition, software developers are turning to a variety of new and exciting methods, technologies, and tools. Agile methodologies are touted as a panacea for those projects that continue to fail to come in on time and under budget. The word agile is proving very popular, with proponents of agile modeling techniques promising to revolutionize our entire approach to systems development. Likewise, others are looking beyond the object-oriented paradigm and seeking to embrace aspect-oriented programming, with its weaves and crosscuts. Supporting all of these new ideas and advances is a maturing base of cutting-edge development tools that assist the software engineer in bringing these techniques to the Java 2 platform.
The IT world is indeed changing rapidly, and not just in terms of technology advances. Today, the speaker’s words are more true than ever: Three months, or you’re dead!
This book does not promote a radically new development methodology that guarantees to slash your development timeframes. Nor is it about rapidity at any cost. It is certainly not about rapidity at the expense of quality. Instead, this book defines a series of solid software engineering practices that target improving both productivity and quality on J2EE projects.
Many of the techniques covered fall just outside of the mainstream. As such, this book offers a fresh perspective on the problems of rapidity for enterprise solutions. Moreover, not all of the techniques will be applicable for every given scenario. Instead, the emphasis is on arming the software engineer with an arsenal of new ideas and practical techniques relevant to the day-today process of building cost-effective, quality solutions.
This book is useful to anyone engaged in the development of enterprise-level systems on the J2EE platform. Whether you are an architect, designer, developer, or tester, this book can help you work more effectively and productively.
Primarily, this book targets anyone who considers himself or herself a software engineer. It is also of interest to anyone who works with or manages developers.
The title software engineer is worthy of further elaboration. IT professionals have a propensity for putting all manner of titles on business cards, from systems analyst and enterprise architect to quality specialist and IT consultant. The true software professional, however, is an extremely versatile individual who is fully capable of fulfilling many, but not necessarily all, of the predefined roles on a project. It is to this type of individual that I apply the term software engineer. Putting aside for a moment the technical description of the role and the associated computer scientist tag, a software engineer is someone who not only knows his or her profession but knows it well. He or she can effectively contribute in all project phases, whether analysis, design, implementation, or testing. Moreover, a software engineer continually looks for new ideas to improve what he or she does and how it is done. In short, a software engineer understands that self-improvement and continuous learning are fundamental activities for an IT professional.
If you think this description applies to you, then you are reading the right book.
The contents of this book are broken up into four logical parts:
Chapter 1: A J2EE Adaptive Foundation. This chapter introduces the concepts behind the creation of an adaptive foundation for rapid development.
Chapter 2: Rapid Application Development. Techniques commonly associated with the rapid development of software, including rapid development languages, approaches to prototyping, and timeboxed development methods, are described in this chapter.
Chapter 3: Embracing Adaptive Methods. Chapter 3 explores the importance of lightweight development methodologies that incorporate an iterative approach to building software.
Chapter 4: Designing for Rapidity. This chapter looks at how the choices we make at design time have implications for the project’s timeframe.
Chapter 5: Modeling Software. The topic of this chapter is the use of models for building software architectures, and it examines how UML diagrams enable the communication, validation, and exploration of system designs.
Chapter 6: Code Generation. We discuss the merits of passive and active code generation. The use of XDoclet for generating boilerplate code artifacts for Enterprise JavaBeans is illustrated by example, along with the use of Apache’s Velocity template engine.
Chapter 7: Rapidity and the Database. The repetitive nature of data access code makes it a prime candidate for code generation. This chapter looks at the time savings to be had from the use of the code generation tool Middlegen, as well as at how object-relational mapping products can ease the process of mixing object-oriented technology with that of relational database technology.
Chapter 8: Model-Driven Architecture. This chapter brings together models with code generation techniques to explore the MDA paradigm. The use of the open source MDA tool AndroMDA is covered by example.
Chapter 9: Scripting. This chapter looks at the benefits of scripting languages and introduces the Java-compatible scripting language Jython.
Chapter 10: Working to Rule. This chapter examines the benefits of using rule engines to maintain business logic. The open source, expert system shell Jess is introduced as an example of a rule-based language.
Chapter 11: Aspect-Oriented Programming. AOP provides new language constructs for modularizing crosscutting concerns. The result is a powerful mechanism for applying changes dynamically to an application. This chapter introduces the AOP language AspectJ and the AOP framework AspectWerkz.
Chapter 12: Optimal Builds. Chapter 12 addresses the importance of having a highly efficient and optimized build process in place for conducting rapid development.
Chapter 13: The Integrated Development Environment. We examine the need to invest in sophisticated and integrated development tools. The open source developer’s workbench Eclipse is introduced as an example of a suitable J2EE development environment.
Chapter 14: Test-Driven Development. The practice of test-driven development is key to defining an approach that is resilient to changing requirements and designs. This chapter looks at the importance of constructing an automated unit test suite and covers the JUnit framework for writing unit tests as well as the use of mock objects in testing.
Chapter 15: Efficient Quality Assurance. The final chapter looks at using automated testing tools for undertaking functional and performance testing. The open source tools HttpUnit and Apache JMeter are covered by example.
The examples included in this book use open source software where possible. This approach provides a low-cost option for trying out the rapid development techniques covered. Where suitable open source software products are not available, I have attempted to select commercial products that offer free trial versions for evaluation purposes. In a few rare exceptions, examples use commercial products that represent a best-of-breed for a particular technology, regardless of cost.
The content of this book is part software management and part software development, as rapid development is not possible without engaging both disciplines.
Although the content of this book spans the entire development process, it is not a definitive text on the lifecycle of a project. Rather, the content encompasses a detailed collection of ideas, processes, and techniques tailored to enterprise-level J2EE developments.
Not all of the techniques are applicable to every situation. Instead, you should familiarize yourself with the ideas presented, then draw upon your own skills and experience to determine which of them adds the most value to your specific project.
The techniques and practices presented all represent best-practice software engineering. The intent is to introduce a wide range of subjects rather than focus on a small number of topics in minute detail. Rapid-fire examples illustrate each of the concepts introduced, which bring you quickly up to speed with a particular topic. Each chapter includes links and references to further resources for more information on all the techniques and practices covered.