Section 5.7. Creating UML Diagrams | Java for ColdFusion Developers

5.7 Creating UML Diagrams

In planning a software application, you generally need to create use cases and user scenarios, class and package diagrams, and perhaps sequence diagrams. We will cover all of these in this chapter so that you will be ready to plan your own applications. The discussion will also serve as a circumambulatory way to approach creating complex Java classes, as we will in Chapter 7.

There are many software packages designed to help developers plan software applications. These packages allow you to create all of the different kinds of diagrams we discuss in this chapter, and more. These include:

Rational Rose
Microsoft Visio
Platinum ERWin

5.7.1 Rational Software

As you might guess, Rational Software makes several products that help developers create their software architecture drawings. Some of these packages are expensive (several thousand dollars) for beginners or small companies. If you aren't sure that you'll have many OOP projects, the Rational products might be needlessly complex. It's not a bad idea to start simple and increase the power of your tools as required. It can also require a large investment of time just to learn how to work with the Rational tools. However, some of the more sophisticated features of Rational Rose really go the extra mile. The Rational programs don't stop at representing your application. Rational knows that you're writing the representation in order to write real code ”and its programs will translate your diagrams directly into the appropriate Java code. That's a huge time saver.

5.7.2 Microsoft Visio

One easy and inexpensive way to get started drawing UML diagrams is Microsoft Visio. This program costs only a couple hundred dollars, is easy to start using, and contains libraries that help you quickly create and organize your diagrams.

There are different editions of Visio. The Professional Edition has the right features to work with most small- to medium- sized projects. It allows you to create more than a dozen different kinds of UML diagrams, as well as six different database schema diagrams, flowcharts, and other items such as organization charts , schedules, and network maps.

In the end, of course, you'll choose what you're comfortable with and what's in your budget. You don't need to use any of these packages to write or plan Java programs. But they can make doing so much easier. You can use a word processor or even an HTML editor to make a basic bordered table to write class diagrams. It gets trickier with the other kinds of diagrams, and this solution is not very easy to modify.

5.7.3 Pencil and Paper

You can also draw out your diagrams with paper and pencil. For this kind of work it is very efficient to use pencil and paper or a large posterboard. This entire package costs about one dollar and is in many cases as fast or faster than using the software packages mentioned above. Once you need to share it digitally, you can scan it in and save it as an image. The obvious downside is that it becomes rather cumbersome to modify. This is, however, a surprisingly common practice and an efficient, workable solution.

In the next several sections, we will look at the more common UML diagrams, what they're for, and how to create them.

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