APPLICATION BUILDER TOOLS

When working with Java Beans, most developers use an application builder tool, a utility
that enables you to configure a set of Beans, connect them together, and produce a
working application. In general, Bean builder tools have the following capabilities.
■ A palette is provided that lists all of the available Beans. As additional Beans
are developed or purchased, they can be added to the palette.
■ A worksheet is displayed that allows the designer to lay out Beans in a graphical
user interface. A designer may drag and drop a Bean from the palette to this
worksheet.
■ Special editors and customizers allow a Bean to be configured. This is the
mechanism by which the behavior of a Bean may be adapted for a particular
environment.
■ Commands allow a designer to inquire about the state and behavior of a
Bean. This information automatically becomes available when a Bean is added
to the palette.
■ Capabilities exist to interconnect Beans. This means that events generated by
one component are mapped to method invocations on other components.

■ When a collection of Beans has been configured and connected, it is possible to
save all of this information in a persistent storage area. At a later time, this
information can then be used to restore the state of the application.
Sun provides two Bean application builder tools. The first is the BeanBox, which is
part of the Bean Developers Kit (BDK). The BDK is the original builder tool provided
by Sun. The second is the new Bean Builder. Because Bean Builder is designed to
supplant the BeanBox, Sun has stopped development of the BDK and all new Bean
applications will be created using Bean Builder.
Although Bean Builder is the future of Bean development, it is not the sole focus of
this chapter. Instead, both BeanBox and Bean Builder are discussed. The reason for this
is that Bean Builder requires Java 2, version 1.4. It is incompatible with earlier versions
of Java 2. This means that readers of this book using Java 2, version 1.2 or version 1.3
will not be able to use Bean Builder. Instead, they must continue to use the BDK. Further,
readers using version 1.4 cannot use the BDK because it is not compatible with Java 2,
version 1.4. So, if you are using version 1.4, then you must use Bean Builder. If you are
using a version of Java prior to 1.4, you must use the BDK. Thus, both approaches are
described here, beginning with the BDK. Keep in mind that the information about Beans,
Bean architecture, JAR files, and so on, apply to either Bean development tool.
One other point: At the time of this writing, Java 2, version 1.4 is a released product,
but Bean Builder is currently in beta testing.