/* ================================================================
* Cewolf : Chart enabling Web Objects Framework
* ================================================================
*
* Project Info: http://cewolf.sourceforge.net
* Project Lead: Guido Laures (guido@laures.de);
*
* (C) Copyright 2002, by Guido Laures
*
* This library 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 library 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
* library; if not, write to the Free Software Foundation, Inc., 59 Temple Place, Suite 330,
* Boston, MA 02111-1307, USA.
*/
package de.laures.cewolf.taglib.util;
import java.io.IOException;
import java.io.Serializable;
import java.rmi.MarshalledObject;
import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;
/**
* @author Guido Laures
*/
public abstract class KeyGenerator {
private static final Log log = LogFactory.getLog(KeyGenerator.class);
private static class NoKeyException extends RuntimeException {
static final long serialVersionUID = -6826954827480537636L;
public NoKeyException (String msg){
super(msg);
}
}
public static int generateKey (Serializable obj) {
if (obj == null) {
NoKeyException ex = new NoKeyException("assertion failed: can not generate key for null,");
throw ex;
}
try {
MarshalledObject mo = new MarshalledObject(obj);
return mo.hashCode();
} catch (IOException ioex) {
log.error("KeyGenerator.generate: IOException during key generation KeyGenerator.generateKey(): "+ioex.getMessage());
throw new NoKeyException(obj + " is not serializable.");
}
}
}