The Business Components for Java framework follows the standard Java/EJB event delegation model for propagating events among middle-tier objects. Publishers (also called senders) fire events, subscribers (also called listeners) respond to them.
Java event types are classes that extend java.util.EventObject. The framework sends an event from a publisher to a subscriber by invoking a method of the RowSetListener interface on the subscriber and passing in an instance of the event type generated. The subscriber registers listeners by using addEventTypeListener() on the publisher.
The publisher defines the set of events it emits by providing addEventTypeListener methods which register specific listeners for those events.
A subscriber implements a specific EventListener interface, RowSetListener, that extends java.util.EventListener. An EventListener interface defines one or more methods to invoke in response to each specific event type handled by the interface.
The following Business Components for Java classes for built-in events can be found in the oracle.jbo package. They can be published by various Business Components and are used to manage three-tier communications.
Event Class |
Description |
JboEvent |
Extends java.util.EventObject. All Business Component events subclass this class. |
NavigationEvent |
Fired when the iterator position in a View Object changes. It provides the following methods:
|
RangeEvent |
Base class for range oriented event. RangeRefreshEvent, and ScrollEvent subclass this class. |
RangeRefreshEvent |
Fired when the range is refreshed, not when a row is updated--use UpdateEvent for that. In addition to RangeEvent methods, it has the following methods:
|
ScrollEvent |
Fired when the range is scrolled. In addition to RangeEvent methods, it has the following methods:
|
RowEvent |
RowEvent is the base class for other row-oriented events. It has the following methods:
|
InsertDeleteEvent |
Used for insert or delete event. In addition to RowEvent methods, it has the following methods:
Note: getRowIndex returns the absolute row index, not range-relative. |
InsertEvent |
Provides a toString method. |
DeleteEvent |
Provides a toString method. |
UpdateEvent |
Adds the following methods:
|