Neither will we concern ourselves with the customizers, which we covered in sufficient detail with our discussion of the first two beans. To see the forced labor behind the beans, check out the complete source code . Building the ProgressBean bean ProgressBean is a simple progress display bean. It is a custom AWT component that displays a percentage value and graphical bar-representation of this value, as shown in the figure below. The current value is exposed as an observable property .
Observable properties are properties whose changes can be observed.
Observers are registered with the bean in the same way that event listeners are, and they are notified whenever a property changes. The ProgressBean class is the main bean class, a simple custom AWT component and Java bean. The lightweight component framework is more efficient than the traditional custom-component framework, requiring fewer resources of the local windowing system. As a component, we automatically inherit the serializability mandated by JavaBeans, and we provide the default no-arg constructor. The int property value is observable, which means that we must inform all interested listeners whenever its value changes.