8.3. Modifying Cache Entries

In a cache entry modified listener event, The getValue() method's behavior is specific to whether the callback is triggered before or after the actual operation has been performed. For example, if event.isPre() is true, then event.getValue() would return the old value, prior to modification. If event.isPre() is false, then event.getValue() would return new value. If the event is creating and inserting a new entry, the old value would be null. For more information about isPre(), see the Red Hat JBoss Data Grid API Documentation's listing for the org.infinispan.notifications.cachelistener.event package.

Listeners can only be configured programmatically by using the methods exposed by the Listenable and FilteringListenable interfaces (which the Cache object implements).

The following example defines a listener in Red Hat JBoss Data Grid that prints some information each time a cache entry is modified:

@Listener
    public class PrintWhenModified {
        @CacheEntryModified
        public void print(CacheEntryModifiedEvent event) {
            System.out.println("Cache entry modified. Details = " + event);
        }
    }

@Listener
    public class PrintWhenModified {
        @CacheEntryModified
        public void print(CacheEntryModifiedEvent event) {
            System.out.println("Cache entry modified. Details = " + event);
        }
    }