Java Beans Tutorial, Part 4: Introduction

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Writing Advanced Beans

Advanced Bean programming is about customization. Beans can be customized in two senses. In both cases, you provide a basic behavior for a Bean and allow its specific behavior to be controlled by end users who interact with the Bean, typically through application builder tools. A Bean can be customized for a specific application either programmatically, through Java code, or visually, through GUI interfaces hosted by application builder tools. In the latter case, you can provide customized dialog boxes and editing tools with sophisticated controls. Such customization tools would be packaged as part of the Bean.

The Bean thus becomes a set of classes, including the Bean proper, as well as other classes that provide a clean, simple, and intuitive interface through which end users can specify precise Bean behavior in applications. Once you've worked through the examples in this segment, you'll have a solid understanding of Beans and will be well on your way to building reusable software components that others will want to use in their programs.

In this concluding segment to the JavaBeans Tutorial, you'll write more advanced Beans. You'll see how to convert old applets and JDK 1.0 programs to Beans. You'll learn about the AWT delegation event model; how Beans can notify other objects about change events; and see how reflection and introspection let you customize the behavior and presentation of your Beans.

Table of Contents

• Converting Applets to Beans
• NervousText as a Bean
• JDK 1.1 Event Handlers
• Making Beans Serializable
• Bound Properties
• Events, Reflection, and Introspection
• New and Old Event Models
• Handling Events with ActionListeners
• Upgrading Event Handlers
• Invoking Reflected Methods
• Customizing Beans for Builder Tools
• Automatically Resized Beans
• Adding a BeanInfo class
• Adding a PropertyEditor
• Reflection and Method Descriptors

Greg Voss is a JavaSoft engineer and OOP specialist. He develops training materials to assist JavaSoft licensees in porting the Java¹ Virtual Machine to new platforms and devices. As a founding team member of the Java Developer Connection, he has contributed articles on JavaBeans, Java Server, and Java language parsing tools.

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¹ As used on this web site, the terms "Java virtual machine" or "JVM" mean a virtual machine for the Java platform.