Java Reference
In-Depth Information
1.
Rules to Ensure Consistency in Writing Interfaces:
For example, the rules say, among other things, that the name of an accessor method
must begin with
get
and that the name of a mutator method must start with
set
.
This same rule has always been a style rule for us in this topic, but it was a “should
do.” In the JavaBeans framework it becomes a “must do.” Of course, there are other
rules as well. This is just a sample rule.
2.
An Event Handling Model:
This is essentially the event-handling model we presented for the AWT and Swing.
(Remember the AWT and Swing were done within the JavaBeans framework.)
3.
Persistence:
Persistence means that an object has an identity that extends beyond one session. For ex-
ample, a
JFrame
of the kind we have seen so far may be used, and when you are finished
using it, it goes away. The next time you use it, it starts out completely new, born again
just as it started before. Persistence means the
JFrame
or other component can retain in-
formation about its former use; its state is saved, for example, in a database someplace.
4.
Introspection:
Introspection is an enhancement of simple accessor and mutator methods. It includes
facilities to find out what access to a component is available as well as providing access.
5.
Builder Support:
These are primarily IDEs (Integrated Development Environments) designed to con-
nect JavaBean components to produce a final application. Some examples are Sun's
Bean Builder, Symantec's Visual Cafe, and Borland's JBuilder.
event
handling
persistence
introspection
What Is a JavaBean?
A
JavaBean
(often called a
JavaBean
component or simply a
Bean
) is a reusable software
component (Java class or classes) that satisfies the requirements of the JavaBeans frame-
work and that can be manipulated in an IDE designed for building applications out of Beans.
What Are Enterprise JavaBeans?
The
Enterprise
JavaBean
framework extends the
JavaBeans
framework to more readily
accommodate business applications.
Self-Test Exercises
5. What is meant by
persistence
?
6. What event-handling model is used with JavaBeans?
