/**
* 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.expiry;
import javax.cache.configuration.
Factory;
import javax.cache.configuration.
FactoryBuilder;
import java.io.
Serializable;
/**
* An {@link ExpiryPolicy} that defines the expiry {@link Duration}
* of a Cache Entry based on the last time it was accessed. Accessed
* does not include a cache update.
*
* @author Greg Luck
* @author Brian Oliver
* @since 1.0
* @see ExpiryPolicy
*/
public final class
AccessedExpiryPolicy implements
ExpiryPolicy,
Serializable {
/**
* The serialVersionUID required for {@link java.io.Serializable}.
*/
public static final long
serialVersionUID = 201305101601L;
/**
* The {@link Duration} a Cache Entry should be available before it expires.
*/
private
Duration expiryDuration;
/**
* Constructs an {@link AccessedExpiryPolicy} {@link ExpiryPolicy}.
*
* @param expiryDuration the {@link Duration} a Cache Entry should exist be
* before it expires after being accessed
*/
public
AccessedExpiryPolicy(
Duration expiryDuration) {
this.
expiryDuration =
expiryDuration;
}
/**
* Obtains a {@link Factory} for an Accessed {@link ExpiryPolicy}.
* @param duration The expiry duration
* @return a {@link Factory} for an Accessed {@link ExpiryPolicy}.
*/
public static
Factory<
ExpiryPolicy>
factoryOf(
Duration duration) {
return new
FactoryBuilder.
SingletonFactory<
ExpiryPolicy>(new
AccessedExpiryPolicy(
duration));
}
/**
* {@inheritDoc}
*/
@
Override
public
Duration getExpiryForCreation() {
//the initial expiry duration is the same as if the entry was accessed
return
expiryDuration;
}
/**
* {@inheritDoc}
*/
@
Override
public
Duration getExpiryForAccess() {
//when a cache entry is accessed, we return the specified expiry duration,
//ignoring the current expiry duration
return
expiryDuration;
}
/**
* {@inheritDoc}
*/
@
Override
public
Duration getExpiryForUpdate() {
//modifying a cache entry has no affect on the current expiry duration
return null;
}
/**
* {@inheritDoc}
*/
@
Override
public int
hashCode() {
final int
prime = 31;
int
result = 1;
result =
prime *
result + ((
expiryDuration == null) ? 0 :
expiryDuration.
hashCode());
return
result;
}
/**
* {@inheritDoc}
*/
@
Override
public boolean
equals(
Object object) {
if (this ==
object) {
return true;
}
if (
object == null) {
return false;
}
if (!(
object instanceof
AccessedExpiryPolicy)) {
return false;
}
AccessedExpiryPolicy other = (
AccessedExpiryPolicy)
object;
if (
expiryDuration == null) {
if (
other.
expiryDuration != null) {
return false;
}
} else if (!
expiryDuration.
equals(
other.
expiryDuration)) {
return false;
}
return true;
}
}