1 /*
   2  * Copyright 2005-2006 Sun Microsystems, Inc.  All Rights Reserved.
   3  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
   4  *
   5  * This code is free software; you can redistribute it and/or modify it
   6  * under the terms of the GNU General Public License version 2 only, as
   7  * published by the Free Software Foundation.  Sun designates this
   8  * particular file as subject to the "Classpath" exception as provided
   9  * by Sun in the LICENSE file that accompanied this code.
  10  *
  11  * This code is distributed in the hope that it will be useful, but WITHOUT
  12  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
  13  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
  14  * version 2 for more details (a copy is included in the LICENSE file that
  15  * accompanied this code).
  16  *
  17  * You should have received a copy of the GNU General Public License version
  18  * 2 along with this work; if not, write to the Free Software Foundation,
  19  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
  20  *
  21  * Please contact Sun Microsystems, Inc., 4150 Network Circle, Santa Clara,
  22  * CA 95054 USA or visit www.sun.com if you need additional information or
  23  * have any questions.
  24  */
  25 
  26 package javax.lang.model.element;
  27 
  28 /**
  29  * Indicates that an unknown kind of element was encountered.  This
  30  * can occur if the language evolves and new kinds of elements are
  31  * added to the {@code Element} hierarchy.  May be thrown by an
  32  * {@linkplain ElementVisitor element visitor} to indicate that the
  33  * visitor was created for a prior version of the language.
  34  *
  35  * @author Joseph D. Darcy
  36  * @author Scott Seligman
  37  * @author Peter von der Ahé
  38  * @see ElementVisitor#visitUnknown
  39  * @since 1.6
  40  */
  41 public class UnknownElementException extends RuntimeException {
  42 
  43     private static final long serialVersionUID = 269L;
  44 
  45     private transient Element element;
  46     private transient Object parameter;
  47 
  48     /**
  49      * Creates a new {@code UnknownElementException}.  The {@code p}
  50      * parameter may be used to pass in an additional argument with
  51      * information about the context in which the unknown element was
  52      * encountered; for example, the visit methods of {@link
  53      * ElementVisitor} may pass in their additional parameter.
  54      *
  55      * @param e the unknown element, may be {@code null}
  56      * @param p an additional parameter, may be {@code null}
  57      */
  58     public UnknownElementException(Element e, Object p) {
  59         super("Unknown element: " + e);
  60         element = e;
  61         this.parameter = p;
  62     }
  63 
  64     /**
  65      * Returns the unknown element.
  66      * The value may be unavailable if this exception has been
  67      * serialized and then read back in.
  68      *
  69      * @return the unknown element, or {@code null} if unavailable
  70      */
  71     public Element getUnknownElement() {
  72         return element;
  73     }
  74 
  75     /**
  76      * Returns the additional argument.
  77      *
  78      * @return the additional argument
  79      */
  80     public Object getArgument() {
  81         return parameter;
  82     }
  83 }