Chapter 4 - Reusing Your Development Efforts—Object-Oriented Patterns

Summary

What We'll Learn in This Chapter

What OO patterns, including both analysis patterns and design patterns, are.

How to use OO patterns effectively in the applications that you create.

How to create new OO patterns.

How to apply OO patterns throughout the life cycle.

What the advantages and disadvantages of OO patterns are.

Considering the number of combinations of operating systems, hardware platforms, and network protocols can you reasonably expect to be able to purchase business objects off the shelf? I'm not so sure. But what I do know is that developers are constantly solving the same problems over and over again. How many of you have been involved with developing inventory-control software? Or human-resource-management software? Or billing software? These problems keep repeating themselves over and over again. Although everyone's inventory-control system is different, the fact is that there is a lot of similarity between the designs of these systems. Wouldn't it be nice to be able to pick a design up off the shelf that has 80—90% of the thinking done for you already and all you have to do is develop the differences that are unique to your organization? That's what object-oriented (OO) patterns are all about, they're blueprints of generic designs that you can apply to the systems that you develop.

Doesn't it always seem as if you're solving the same problems over and over again? If you personally haven't solved a given problem before, then chances are pretty good you could hunt somebody down who had tackled the same, or at least a similar problem in the past.