oracle.toplink.essentials.internal.identitymaps.WeakCacheKey Maven / Gradle / Ivy
/*
* The contents of this file are subject to the terms
* of the Common Development and Distribution License
* (the "License"). You may not use this file except
* in compliance with the License.
*
* You can obtain a copy of the license at
* glassfish/bootstrap/legal/CDDLv1.0.txt or
* https://glassfish.dev.java.net/public/CDDLv1.0.html.
* See the License for the specific language governing
* permissions and limitations under the License.
*
* When distributing Covered Code, include this CDDL
* HEADER in each file and include the License file at
* glassfish/bootstrap/legal/CDDLv1.0.txt. If applicable,
* add the following below this CDDL HEADER, with the
* fields enclosed by brackets "[]" replaced with your
* own identifying information: Portions Copyright [yyyy]
* [name of copyright owner]
*/
// Copyright (c) 1998, 2007, Oracle. All rights reserved.
package oracle.toplink.essentials.internal.identitymaps;
import java.lang.ref.*;
import java.util.Vector;
/**
* Purpose: Container class for storing objects in an IdentityMap.
* The weak cache key uses a weak reference to allow garbage collection of its object.
* The cache key itself however will remain and thus should cleaned up every no and then.
*
Responsibilities:
* - Hold key and object.
*
- Maintain and update the current writeLockValue.
*
* @since TOPLink/Java 1.0
*/
public class WeakCacheKey extends CacheKey {
/** Reference is maintained weak to allow garbage collection */
protected WeakReference reference;
/**
* Initialize the newly allocated instance of this class.
* @param primaryKey contains values extracted from the object
* @param writeLockValue is the write lock value, null if optimistic locking not being used for this object.
* @param readTime the time TopLInk read the cache key
*/
public WeakCacheKey(Vector primaryKey, Object object, Object writeLockValue, long readTime) {
super(primaryKey, object, writeLockValue, readTime);
}
public Object getObject() {
return getReference().get();
}
public WeakReference getReference() {
return reference;
}
public void setObject(Object object) {
setReference(new WeakReference(object));
}
protected void setReference(WeakReference reference) {
this.reference = reference;
}
}