javax.cache.event.CacheEntryEvent Maven / Gradle / Ivy
/**
* Copyright 2011-2016 Terracotta, Inc.
* Copyright 2011-2016 Oracle America Incorporated
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package javax.cache.event;
import javax.cache.Cache;
import javax.cache.configuration.CacheEntryListenerConfiguration;
import java.util.EventObject;
/**
* A Cache entry event base class.
*
* @param the type of key
* @param the type of value
* @author Greg Luck
* @since 1.0
*/
public abstract class CacheEntryEvent extends EventObject
implements Cache.Entry {
private EventType eventType;
/**
* Constructs a cache entry event from a given cache as source
*
* @param source the cache that originated the event
* @param eventType the event type for this event
*/
public CacheEntryEvent(Cache source, EventType eventType) {
super(source);
this.eventType = eventType;
}
/**
* {@inheritDoc}
*/
@Override
public final Cache getSource() {
return (Cache) super.getSource();
}
/**
* Returns the value stored in the cache when this entry was created or updated.
*
* The value will be available
* for {@link CacheEntryCreatedListener} and {@link CacheEntryUpdatedListener}.
* Returns the same value as {@link #getOldValue()} for
* {@link CacheEntryExpiredListener} and {@link CacheEntryRemovedListener}.
* Cache clients that need to maintain compatibility with JSR107 version 1.0
* cache implementations, need to use this method for retrieving the expired
* or removed value. When using cache implementations compatible with JSR107
* version 1.1, clients should prefer the method {@link #getOldValue()}.
*
* @return the value corresponding to this entry
* @see #getOldValue()
*/
@Override
public abstract V getValue();
/**
* Returns the previous value that existed for entry in the cache before
* modification or removal.
*
* The old value will be available
* for {@link CacheEntryUpdatedListener}, {@link CacheEntryExpiredListener}
* and {@link CacheEntryRemovedListener}
* if {@link CacheEntryListenerConfiguration#isOldValueRequired()} is true.
* The old value may be available for {@link CacheEntryUpdatedListener},
* {@link CacheEntryExpiredListener} and {@link CacheEntryRemovedListener}
* if {@link CacheEntryListenerConfiguration#isOldValueRequired()} is false.
*
* @return the previous value or null if there was no previous
* value or the previous value is not available
*/
public abstract V getOldValue();
/**
* Whether the old value is available. The old value will be available
* for {@link CacheEntryUpdatedListener}, {@link CacheEntryExpiredListener}
* and {@link CacheEntryRemovedListener}
* if {@link CacheEntryListenerConfiguration#isOldValueRequired()} is true.
* The old value may be available for {@link CacheEntryUpdatedListener},
* {@link CacheEntryExpiredListener} and {@link CacheEntryRemovedListener}
* if {@link CacheEntryListenerConfiguration#isOldValueRequired()} is false.
*
* @return true if the old value is definitely available
*/
public abstract boolean isOldValueAvailable();
/**
* Gets the event type of this event
*
* @return the event type.
*/
public final EventType getEventType() {
return eventType;
}
}