openwfe.org.misc.UniqueIdGenerator Maven / Gradle / Ivy
/*
* Copyright (c) 2001-2006, John Mettraux, OpenWFE.org
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions are met:
*
* . Redistributions of source code must retain the above copyright notice, this
* list of conditions and the following disclaimer.
*
* . 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.
*
* . Neither the name of the "OpenWFE" nor the names of its contributors may be
* used to endorse or promote products derived from this software without
* specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
* AND ANY EXPRESS 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 THE COPYRIGHT OWNER OR 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.
*
* $Id: UniqueIdGenerator.java 2713 2006-06-01 14:38:45Z jmettraux $
*/
//
// UniqueIdGenerator.java
//
// [email protected]
//
// generated with
// jtmpl 1.1.00 16.08.2003 John Mettraux ([email protected])
//
package openwfe.org.misc;
/**
* A generator that you instantiate and then use as a utility instance.
*
* CVS Info :
*
$Author: jmettraux $
*
$Id: UniqueIdGenerator.java 2713 2006-06-01 14:38:45Z jmettraux $
*
* @author [email protected]
*/
public class UniqueIdGenerator
{
/*
private final static org.apache.log4j.Logger log = org.apache.log4j.Logger
.getLogger(UniqueIdGenerator.class.getName());
*/
//
// CONSTANTS & co
public final static String P_ID_PREFIX
= "idPrefix";
protected static long lastGivenId = 0;
//
// FIELDS
protected int iPrefix = -1;
protected String sPrefix = null;
//
// CONSTRUCTORS
/**
* Instantiates a basic id generator : one that returns Long instances
* as ids
*/
public UniqueIdGenerator ()
{
super();
}
/**
* the String prefix will always be prepended to the long ids
* generated, so you'll end up with a String uniqueId
*/
public UniqueIdGenerator (final String sPrefix)
{
super();
this.sPrefix = sPrefix;
}
/**
* Instantiates a unique id generator that prefixes all its produced
* ids with the given iPrefix, which must be comprised between 10 and 99.
*/
public UniqueIdGenerator (final int iPrefix)
{
super();
if (iPrefix < 10 || iPrefix > 99)
{
throw new RuntimeException
("iPrefix must be comprised between 10 and 99 included");
}
this.iPrefix = iPrefix;
}
//
// METHODS
/**
* generates a unique id and prepares for generating the next one
*/
public synchronized Object generateUniqueId ()
{
long id = System.currentTimeMillis();
if (id <= lastGivenId)
{
id = lastGivenId+1;
}
lastGivenId = id;
if (this.sPrefix != null)
return this.sPrefix + id;
if (this.iPrefix > 9)
return new Long(""+this.iPrefix+""+id);
return new Long(id);
// not returning directly lastGivenId...
}
/**
* A shortcut for
*
* return ((Long)generateUniqueId).longValue();
*
* If you instantiated the generator with a String prefix,
* calling this method will throw a ClassCastException.
*/
public long generateUniqueLongId ()
{
return ((Long)generateUniqueId()).longValue();
}
}