eWebProgrammer eweb   

Java Beans   «Prev  Next»
Lesson 14 Constrained properties
Objective Learn about constrained properties.
JavaBeans support
constrained properties, which are properties that enable an outside party to validate a change in them before accepting the change.
When you attempt to change the value of a constrained property, the value is first checked with an outside validation source that accepts or rejects the change.
Property change rejections come in the form of PropertyVetoException exceptions, which are handled by the Bean containing the property.
When a rejection exception occurs, the Bean is responsible for reverting the property back to its prior value and issuing a new property change notification for the reversion.
JavaBean Constrained Property
Constrained property: a property that enables an interested party to perform a validation on a new property value before accepting the modification.
In the next lesson, how constrained properties work will be discussed.