Chapter 16: Conclusion--Making J2EE Work for You

Overview

We've covered a lot of ground in this book. While we haven't attempted to look at the whole of J2EE, we have looked in detail at those features and components that are most useful for building typical real-world applications. While we've focused on web applications, most of the issues discussed are relevant to all client types.

I feel that too much J2EE literature takes a highly theoretical approach that doesn't meet the challenges of real-world enterprise development. In this book, I've tried to take a practical and pragmatic approach to J2EE design and development. In particular, I've emphasized on:

• Simplicity
  To a large extent, adopting a framework such as a J2EE application server is to simplify application code.If used correctly, J2EE can help to free developers from some of the most complex of coding tasks.

• Maintainability
  Over 80% of the cost of software is spent on maintenance, rather than development, so it's imperative to develop applications that are easy to maintain.

• Performance
  Performance is an important consideration in most real applications - and especially, web applications. J2EE application servers cannot free us from the responsibility of designing applications to ensure satisfactory performance, and we need to be prepared to make design trade-offs if necessary.

• Productivity
  Applications must be developed in reasonable time. Productivity is a vital consideration, which must be taken into account throughout the project lifecycle.

We've considered not merely the J2EE specifications, but how some important features are implemented in leading servers. J2EE now has several years behind it, and while many features have proven their value, others have not been so successful. We must take this experience into account.

In this chapter, we'll consider some of the lessons that we've drawn.