Developing Java Beans

Preface

JavaBeans is one of the most important developments in Java™ since its inception. It is Java’s component architecture, which allows components built with Java to be used in graphical programming environments. Graphical development environments let you configure components by specifying aspects of their visual appearance (like the color or label of a button) in addition to the interactions between components (what happens when you click on a button or select a menu item). This means that someone can use a graphical tool to connect some Beans together and make an application without actually writing any Java code—in fact, without doing any programming at all. Developing an application isn’t necessarily a matter of producing thousands of lines of code that can only be read by computer professionals. It’s more like working with Lego blocks: you can build large structures using snap-together pieces. The result is that applications can be created by people who are good at designing user interfaces and aspects of the interaction between the user and the computer. The guts of an application can be written by software developers, who are great at coding, but not necessarily good at understanding users. This is how it should be, and in fact how it is in many other industries. The engineer who designed the engine of your car is certainly not the same person who designed the interior. JavaBeans allows us to make the same kind of distinction in the software business.

As Beans become widely available, we will see more developers using them to build applications. But before these applications can be built, someone has to build the components. That’s what this book is all about.

You won’t find any hype in this book, and you won’t find vague descriptions of technology that may or may not appear in the future. JavaBeans is here now, and programmers must have the information at hand to begin creating components. So if you’re ready to get right into the techniques and concepts used by the JavaBeans architecture, and if you want to understand the underpinnings of the technology that makes it work, this book is for you.

Intended Audience

This book is for everyone who wants to know how to build reusable components using the JavaBeans architecture and Java class libraries. It is designed to be used by programmers, students, and professionals that are already familiar with Java, so it doesn’t concentrate on any of the basic concepts or syntax of the language. However, if you are experienced with other object-oriented languages such as C++ or Smalltalk, you should be able to follow along. If you aren’t familiar with Java, you may want to keep a book on the Java language close by, like the Java Language Reference (O’Reilly). In any case, the material should prove useful to both novice and experienced programmers.

One chapter discusses the interaction between JavaBeans and ActiveX components, and has some examples using Visual Basic. I assume that readers interested in this topic are already familiar with VB and the ActiveX component architecture, and don’t attempt to explain them. Many good books on Visual Basic are available if you need an introduction.