1.1 --- /dev/null	Thu Jan 01 00:00:00 1970 +0000
     1.2 +++ b/java/cewolf-1.0/src/main/java/de/laures/cewolf/taglib/util/KeyGenerator.java	Sat Feb 28 21:31:02 2009 +0100
     1.3 @@ -0,0 +1,58 @@
     1.4 +/* ================================================================
     1.5 + * Cewolf : Chart enabling Web Objects Framework
     1.6 + * ================================================================
     1.7 + *
     1.8 + * Project Info:  http://cewolf.sourceforge.net
     1.9 + * Project Lead:  Guido Laures (guido@laures.de);
    1.10 + *
    1.11 + * (C) Copyright 2002, by Guido Laures
    1.12 + *
    1.13 + * This library is free software; you can redistribute it and/or modify it under the terms
    1.14 + * of the GNU Lesser General Public License as published by the Free Software Foundation;
    1.15 + * either version 2.1 of the License, or (at your option) any later version.
    1.16 + *
    1.17 + * This library is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY;
    1.18 + * without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
    1.19 + * See the GNU Lesser General Public License for more details.
    1.20 + *
    1.21 + * You should have received a copy of the GNU Lesser General Public License along with this
    1.22 + * library; if not, write to the Free Software Foundation, Inc., 59 Temple Place, Suite 330,
    1.23 + * Boston, MA 02111-1307, USA.
    1.24 + */
    1.25 +
    1.26 +package de.laures.cewolf.taglib.util;
    1.27 +
    1.28 +import java.io.IOException;
    1.29 +import java.io.Serializable;
    1.30 +import java.rmi.MarshalledObject;
    1.31 +
    1.32 +import org.apache.commons.logging.Log;
    1.33 +import org.apache.commons.logging.LogFactory;
    1.34 +
    1.35 +/**
    1.36 + * @author  Guido Laures
    1.37 + */
    1.38 +public abstract class KeyGenerator {
    1.39 +    
    1.40 +    private static final Log log = LogFactory.getLog(KeyGenerator.class);
    1.41 +
    1.42 +    private static class NoKeyException extends RuntimeException {
    1.43 +        public NoKeyException(String msg){
    1.44 +            super(msg);
    1.45 +        }
    1.46 +    }
    1.47 +
    1.48 +    public static int generateKey(Serializable obj) {
    1.49 +        if (obj == null) {
    1.50 +            NoKeyException ex = new NoKeyException("assertion failed: can not generate key for null,");
    1.51 +            throw ex;
    1.52 +        }
    1.53 +        try {
    1.54 +            MarshalledObject mo = new MarshalledObject(obj);
    1.55 +            return mo.hashCode();
    1.56 +        } catch (IOException ioex) {
    1.57 +            log.error("IOException during key generation KeyGenerator.generateKey()", ioex);
    1.58 +            throw new NoKeyException(obj + " is not serializable.");
    1.59 +        }
    1.60 +    }
    1.61 +}