001    /* InvalidClassException.java -- deserializing a class failed
002       Copyright (C) 1998, 2002 Free Software Foundation, Inc.
003    
004    This file is part of GNU Classpath.
005    
006    GNU Classpath is free software; you can redistribute it and/or modify
007    it under the terms of the GNU General Public License as published by
008    the Free Software Foundation; either version 2, or (at your option)
009    any later version.
010    
011    GNU Classpath is distributed in the hope that it will be useful, but
012    WITHOUT ANY WARRANTY; without even the implied warranty of
013    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
014    General Public License for more details.
015    
016    You should have received a copy of the GNU General Public License
017    along with GNU Classpath; see the file COPYING.  If not, write to the
018    Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
019    02110-1301 USA.
020    
021    Linking this library statically or dynamically with other modules is
022    making a combined work based on this library.  Thus, the terms and
023    conditions of the GNU General Public License cover the whole
024    combination.
025    
026    As a special exception, the copyright holders of this library give you
027    permission to link this library with independent modules to produce an
028    executable, regardless of the license terms of these independent
029    modules, and to copy and distribute the resulting executable under
030    terms of your choice, provided that you also meet, for each linked
031    independent module, the terms and conditions of the license of that
032    module.  An independent module is a module which is not derived from
033    or based on this library.  If you modify this library, you may extend
034    this exception to your version of the library, but you are not
035    obligated to do so.  If you do not wish to do so, delete this
036    exception statement from your version. */
037    
038    
039    package java.io;
040    
041    /**
042     * This exception is thrown when there is some sort of problem with a
043     * class during a serialization operation.  This could be:<br><ul>
044     * <li>the serial version of the class doesn't match</li>
045     * <li>the class contains unknown datatypes</li>
046     * <li>the class does not have an accessible no-arg constructor</li>
047     * </ul>.
048     *
049     * <p>The field <code>classname</code> will contain the name of the
050     * class that caused the problem if known.  The getMessage() method
051     * for this exception will always include the name of that class
052     * if known.
053     *
054     * @author Aaron M. Renn (arenn@urbanophile.com)
055     * @since 1.1
056     * @status updated to 1.4
057     */
058    public class InvalidClassException extends ObjectStreamException
059    {
060      /**
061       * Compatible with JDK 1.1+.
062       */
063      private static final long serialVersionUID = -4333316296251054416L;
064    
065      /**
066       * The name of the class which encountered the error.
067       *
068       * @serial the classname causing the error
069       */
070      public String classname;
071    
072      /**
073       * Create an exception with a descriptive error message, but a null
074       * classname.
075       *
076       * @param message the descriptive error message
077       */
078      public InvalidClassException(String message)
079      {
080        super(message);
081      }
082    
083      /**
084       * Create an exception with a descriptive error message, and the name of
085       * the class that caused the problem.
086       *
087       * @param classname the name of the faulty class
088       * @param message the descriptive error message
089       */
090      public InvalidClassException(String classname, String message)
091      {
092        super(message);
093        this.classname = classname;
094      }
095    
096      /**
097       * Returns the descriptive error message for this exception. It will
098       * include the class name that caused the problem if known, in the format:
099       * <code>[classname][; ][super.getMessage()]</code>.
100       *
101       * @return A descriptive error message, may be null
102       */
103      public String getMessage()
104      {
105        String msg = super.getMessage();
106        if (msg == null)
107          return classname;
108        return (classname == null ? "" : classname + "; ") + msg;
109      }
110    }
111