/**
* Redistribution and use of this software and associated documentation
* ("Software"), with or without modification, are permitted provided
* that the following conditions are met:
*
* 1. Redistributions of source code must retain copyright
* statements and notices. Redistributions must also contain a
* copy of this document.
*
* 2. Redistributions in binary form must reproduce the
* above copyright notice, this list of conditions and the
* following disclaimer in the documentation and/or other
* materials provided with the distribution.
*
* 3. The name "Exolab" must not be used to endorse or promote
* products derived from this Software without prior written
* permission of Intalio, Inc. For written permission,
* please contact info@exolab.org.
*
* 4. Products derived from this Software may not be called "Exolab"
* nor may "Exolab" appear in their names without prior written
* permission of Intalio, Inc. Exolab is a registered
* trademark of Intalio, Inc.
*
* 5. Due credit should be given to the Exolab Project
* (http://www.exolab.org/).
*
* THIS SOFTWARE IS PROVIDED BY INTALIO, INC. AND CONTRIBUTORS
* ``AS IS'' AND ANY EXPRESSED OR IMPLIED WARRANTIES, INCLUDING, BUT
* NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND
* FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL
* INTALIO, INC. OR ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT,
* INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
* (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
* SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
* STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
* ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED
* OF THE POSSIBILITY OF SUCH DAMAGE.
*
* Copyright 1999 (C) Intalio, Inc. All Rights Reserved.
*
* $Id$
*/
package org.exolab.castor.mapping;
import java.io.Serializable;
import java.util.HashMap;
import java.util.Map;
/**
* The access mode for a class. This object is used by class
* descriptors to specify the access mode for a class.
* <p>
* In persistent storage each class is defined as having one of three
* access modes:
* <ul>
* <li>Read only
* <li>Shared (aka optimistic locking)
* <li>Exclusive (aka pessimistic locking)
* <li>DbLocked (database lock)
* </ul>
* Transactions typically access objects based on the specified access
* mode. A transaction may be requested to access any object as read
* only or exclusive, but may not access exclusive objects as shared.
*
* @author <a href="arkin@intalio.com">Assaf Arkin</a>
* @author <a href="mailto:ralf DOT joachim AT syscon DOT eu">Ralf Joachim</a>
* @version $Revision$ $Date: 2006-04-25 15:08:23 -0600 (Tue, 25 Apr 2006) $
*/
public class AccessMode implements Cloneable, Comparable, Serializable {
//-------------------------------------------------------------------------
/** SerialVersionUID */
private static final long serialVersionUID = -7113303922354626951L;
private static final Map IDS = new HashMap(7);
private static final Map NAMES = new HashMap(7);
//-------------------------------------------------------------------------
/**
* Read only access. Objects can be read but are not made
* persistent and changes to objects are not reflected in
* persistent storage.
*/
public static final AccessMode ReadOnly
= new AccessMode((short) 0, "read-only");
/**
* Shared access. Objects can be read by multiple concurrent
* transactions. Equivalent to optimistic locking.
*/
public static final AccessMode Shared
= new AccessMode((short) 1, "shared");
/**
* Exclusive access. Objects can be access by a single transaction
* at any given time. Equivalent to pessimistic locking.
*/
public static final AccessMode Exclusive
= new AccessMode((short) 2, "exclusive");
/**
* DbLocked access. Objects can be access by a single transaction
* at any given time, and a lock is acquired in the database.
*/
public static final AccessMode DbLocked
= new AccessMode((short) 3, "db-locked");
//-------------------------------------------------------------------------
/**
* Returns the access mode from the name. If <tt>accessMode</tt>
* is null, return the default access mode ({@link #Shared}).
* Otherwise returns the named access mode.
*
* @param accessMode The access mode name
* @return The access mode
*/
public static AccessMode valueOf(final String accessMode) {
AccessMode mode = (AccessMode) NAMES.get(accessMode);
if (mode != null) {
return mode;
}
throw new IllegalArgumentException("Unrecognized access mode");
}
public static AccessMode valueOf(final short accessMode) {
AccessMode mode = (AccessMode) IDS.get(new Short(accessMode));
if (mode != null) {
return mode;
}
throw new IllegalArgumentException("Unrecognized access mode");
}
//-------------------------------------------------------------------------
/**
* The id of this access mode as originally used at Database.load() and
* Query.execute().
*/
private short _id;
/**
* The name of this access mode as it would appear in a mapping file.
*/
private String _name;
//-------------------------------------------------------------------------
private AccessMode(final short id, final String name) {
_id = id;
_name = name;
IDS.put(new Short(id), this);
NAMES.put(name, this);
}
public short getId() { return _id; }
public String getName() { return _name; }
//-------------------------------------------------------------------------
/**
* Returns the String representation of this kind.
*
* @return String representation of this kind.
*/
public String toString() {
return _name;
}
/**
* Clone only returns the one and only instance of this kind.
*
* @return The original instance.
*/
public Object clone() {
return this;
}
/**
* Returns if the specified object and this are one and the same instance.
*
* @param other Object to be compared with this instance.
* @return <code>true</code> if other equals this else <code>false</code>.
*/
public boolean equals(final Object other) {
return (this == other);
}
/**
* Returns the hash code of this object.
*
* @return Hash code of this object.
*/
public int hashCode() {
return _id;
}
/**
* Compares id against id of the specified object. So this
* method is inconsistent with {@link #equals(Object)}.
*
* @param other Object to be compared with this instance.
* @return A negative integer, zero, or a positive integer as this object
* is less than, equal to, or greater than the specified object.
*/
public int compareTo(final Object other) {
return compareTo((AccessMode) other);
}
public int compareTo(final AccessMode other) {
return _id - other._id;
}
/**
* Called during deserialization.
*
* @return The existing instance of the enum. <br>So you can use '=='
* like 'equals' even if you use a deserialized Enum.
*/
protected Object readResolve() {
return NAMES.get(_name);
}
//-------------------------------------------------------------------------
}