org.jboss.modules.ref.Reference Maven / Gradle / Ivy
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* JBoss, Home of Professional Open Source.
* Copyright 2010, Red Hat, Inc., and individual contributors
* as indicated by the @author tags. See the copyright.txt file in the
* distribution for a full listing of individual contributors.
*
* This is free software; you can redistribute it and/or modify it
* under the terms of the GNU Lesser General Public License as
* published by the Free Software Foundation; either version 2.1 of
* the License, or (at your option) any later version.
*
* This software is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public
* License along with this software; if not, write to the Free
* Software Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA
* 02110-1301 USA, or see the FSF site: http://www.fsf.org.
*/
package org.jboss.modules.ref;
/**
* An enhanced reference type with a type-safe attachment.
*
* @param the reference value type
* @param the attachment type
*
* @see java.lang.ref.Reference
*
* @author David M. Lloyd
*/
public interface Reference {
/**
* Get the value, or {@code null} if the reference has been cleared.
*
* @return the value
*/
T get();
/**
* Get the attachment, if any.
*
* @return the attachment
*/
A getAttachment();
/**
* Clear the reference.
*/
void clear();
/**
* Get the type of the reference.
*
* @return the type
*/
Type getType();
/**
* A reference type.
*
* @apiviz.exclude
*/
enum Type {
/**
* A strong reference.
*/
STRONG,
/**
* A weak reference.
*/
WEAK,
/**
* A phantom reference.
*/
PHANTOM,
/**
* A soft reference.
*/
SOFT,
/**
* A {@code null} reference.
*/
NULL,
}
}