001/* ActivationException.java -- general Activation exception
002   Copyright (c) 1996, 1997, 1998, 1999, 2002 Free Software Foundation, Inc.
003
004This file is part of GNU Classpath.
005
006GNU Classpath is free software; you can redistribute it and/or modify
007it under the terms of the GNU General Public License as published by
008the Free Software Foundation; either version 2, or (at your option)
009any later version.
010
011GNU Classpath is distributed in the hope that it will be useful, but
012WITHOUT ANY WARRANTY; without even the implied warranty of
013MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
014General Public License for more details.
015
016You should have received a copy of the GNU General Public License
017along with GNU Classpath; see the file COPYING.  If not, write to the
018Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
01902110-1301 USA.
020
021Linking this library statically or dynamically with other modules is
022making a combined work based on this library.  Thus, the terms and
023conditions of the GNU General Public License cover the whole
024combination.
025
026As a special exception, the copyright holders of this library give you
027permission to link this library with independent modules to produce an
028executable, regardless of the license terms of these independent
029modules, and to copy and distribute the resulting executable under
030terms of your choice, provided that you also meet, for each linked
031independent module, the terms and conditions of the license of that
032module.  An independent module is a module which is not derived from
033or based on this library.  If you modify this library, you may extend
034this exception to your version of the library, but you are not
035obligated to do so.  If you do not wish to do so, delete this
036exception statement from your version. */
037
038package java.rmi.activation;
039
040/**
041 * General exception class for <code>java.rmi.activation</code>.
042 *
043 * @author unknown
044 * @since 1.2
045 * @status updated to 1.4
046 */
047public class ActivationException extends Exception
048{
049  /**
050   * Compatible with JDK 1.2+.
051   */
052  private static final long serialVersionUID = -4320118837291406071L;
053
054  /**
055   * The cause of this exception. This pre-dates the exception chaining
056   * of Throwable; and although you can change this field, you are wiser
057   * to leave it alone.
058   *
059   * @serial the exception cause
060   */
061  public Throwable detail;
062
063  /**
064   * Create an exception with no message, and cause initialized to null.
065   */
066  public ActivationException()
067  {
068    this(null, null);
069  }
070
071  /**
072   * Create an exception with the given message, and cause initialized to null.
073   *
074   * @param s the message
075   */
076  public ActivationException(String s)
077  {
078    this(s, null);
079  }
080
081  /**
082   * Create an exception with the given message and cause.
083   *
084   * @param s the message
085   * @param ex the cause
086   */
087  public ActivationException(String s, Throwable ex)
088  {
089    super(s, ex);
090    detail = ex;
091  }
092
093  /**
094   * This method returns a message indicating what went wrong, in this
095   * format:
096   * <code>super.getMessage() + (detail == null ? ""
097   *    : "; nested exception is:\n\t" + detail)</code>.
098   *
099   * @return the chained message
100   */
101  public String getMessage()
102  {
103    if (detail == this || detail == null)
104      return super.getMessage();
105    return super.getMessage() + "; nested exception is:\n\t" + detail;
106  }
107
108  /**
109   * Returns the cause of this exception. Note that this may not be the
110   * original cause, thanks to the <code>detail</code> field being public
111   * and non-final (yuck). However, to avoid violating the contract of
112   * Throwable.getCause(), this returns null if <code>detail == this</code>,
113   * as no exception can be its own cause.
114   *
115   * @return the cause
116   * @since 1.4
117   */
118  public Throwable getCause()
119  {
120    return detail == this ? null : detail;
121  }
122}