javax.cache.event

Interface CacheEntryListener<K,V>

Type Parameters:

K - the type of key

V - the type of value

All Superinterfaces:

EventListener

All Known Subinterfaces:

CacheEntryCreatedListener<K,V>, CacheEntryExpiredListener<K,V>, CacheEntryRemovedListener<K,V>, CacheEntryUpdatedListener<K,V>

public interface CacheEntryListener<K,V>
extends EventListener

A tagging interface for cache entry listeners.

Sub-interfaces exist for the various cache events allowing a listener to be created which implements only those listeners it is interested in.

Listeners should be implemented with care. In particular it is important to consider their impact on performance and latency.

Listeners:

• are fired after the entry is mutated in the cache
• if synchronous are fired, for a given key, in the order in which events occur
• block the calling thread until the listener returns, where the listener was registered as synchronous
• which are asynchronous iterate through multiple events with an undefined ordering, except that events on the same key are in the order in which the events occur.

Listeners follow the observer pattern. An exception thrown by a listener does not cause the cache operation to fail.

Listeners can only throw CacheEntryListenerException. Caching implementations must catch any other Exception from a listener, then wrap and rethrow it as a CacheEntryListenerException.

A listener which mutates a cache on the CacheManager may cause a deadlock. Detection and response to deadlocks is implementation specific.

A listener on a transactional cache is executed orthogonally to the transaction. If synchronous it is executed after the mutation and not after the transaction commits, and if asynchronous the timing is undefined. A listener which throws an exception will not affect the transaction. A transaction which is rolled back will not unfire a listener.

Since:

1.0

Author:

Yannis Cosmadopoulos, Greg Luck

See Also:

CacheEntryCreatedListener, CacheEntryUpdatedListener, CacheEntryRemovedListener, CacheEntryExpiredListener, EventType