Event Handling APIs

Code your event handlers to do minimal work before returning control to GemFire.

For example, a listener implementation may hand off the event to a thread pool that processes the event on its thread rather than the listener thread. Exceptions thrown by the listeners are caught by GemFire and logged.

• RegionEvent class. Provides information about the event, such as what region the event originated in, whether the event originated in a cache remote to the event handler, and whether the event resulted from a distributed operation.
• EntryEvent class. Provides all available information for the RegionEvent. It also provides entry-specific information, such as the old and new entry values and whether the event resulted from a load operation.
• ICacheLoader application callback interface. Loads data into a region.
• ICacheWriter application callback interface. Synchronously handles region and entry events before the events occur. Entry events are create, update, invalidate, and destroy. Region events are invalidate and destroy. This class has the ability to abort events.
• ICacheListener application callback interface. Asynchronously handles region and entry events. Listeners receive notifications when entries in a region change, or when changes occur to the region attributes themselves. Entry events are create, update, invalidate, and destroy. Region events are invalidate and destroy. Multiple events can cause concurrent invocation of ICacheListener methods. If event A occurs before event B, there is no guarantee that their corresponding ICacheListener method invocations will occur in the same order.