001/* RemoteException.java -- common superclass for exceptions in java.rmi
002   Copyright (c) 1996, 1997, 1998, 1999, 2002, 2006 
003   Free Software Foundation, Inc.
004
005This file is part of GNU Classpath.
006
007GNU Classpath is free software; you can redistribute it and/or modify
008it under the terms of the GNU General Public License as published by
009the Free Software Foundation; either version 2, or (at your option)
010any later version.
011
012GNU Classpath is distributed in the hope that it will be useful, but
013WITHOUT ANY WARRANTY; without even the implied warranty of
014MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
015General Public License for more details.
016
017You should have received a copy of the GNU General Public License
018along with GNU Classpath; see the file COPYING.  If not, write to the
019Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
02002110-1301 USA.
021
022Linking this library statically or dynamically with other modules is
023making a combined work based on this library.  Thus, the terms and
024conditions of the GNU General Public License cover the whole
025combination.
026
027As a special exception, the copyright holders of this library give you
028permission to link this library with independent modules to produce an
029executable, regardless of the license terms of these independent
030modules, and to copy and distribute the resulting executable under
031terms of your choice, provided that you also meet, for each linked
032independent module, the terms and conditions of the license of that
033module.  An independent module is a module which is not derived from
034or based on this library.  If you modify this library, you may extend
035this exception to your version of the library, but you are not
036obligated to do so.  If you do not wish to do so, delete this
037exception statement from your version. */
038
039package java.rmi;
040
041import java.io.IOException;
042
043/**
044 * The superclass of exceptions related to RMI (remote method invocation).
045 * Classes that implement <code>java.rmi.Remote</code> should list this
046 * exception in their throws clause.
047 *
048 * @author unknown
049 * @since 1.1
050 * @status updated to 1.4
051 */
052public class RemoteException extends IOException
053{
054  /**
055   * Compatible with JDK 1.2+.
056   */
057  private static final long serialVersionUID = -5148567311918794206l;
058
059  /**
060   * The cause of this exception. This pre-dates the exception chaining
061   * of Throwable; and although you can change this field, you are wiser
062   * to leave it alone.
063   *
064   * @serial the exception cause
065   */
066  public Throwable detail;
067
068  /**
069   * Create an exception with no message, and cause initialized to null.
070   */
071  public RemoteException()
072  {
073    this(null, null);
074  }
075
076  /**
077   * Create an exception with the given message, and cause initialized to null.
078   *
079   * @param s the message
080   */
081  public RemoteException(String s)
082  {
083    this(s, null);
084  }
085
086  /**
087   * Create an exception with the given message and cause.
088   *
089   * @param s the message
090   * @param e the cause
091   */
092  public RemoteException(String s, Throwable e)
093  {
094    super(s);
095    initCause(e);
096    detail = e;
097  }
098
099  /**
100   * This method returns a message indicating what went wrong, in this
101   * format:
102   * <code>super.getMessage() + (detail == null ? ""
103   *    : "; nested exception is:\n\t" + detail)</code>.
104   *
105   * @return the chained message
106   */
107  public String getMessage()
108  {
109    if (detail == this || detail == null)
110      return super.getMessage();
111    return super.getMessage() + "; nested exception is:\n\t" + detail;
112  }
113
114  /**
115   * Returns the cause of this exception. Note that this may not be the
116   * original cause, thanks to the <code>detail</code> field being public
117   * and non-final (yuck). However, to avoid violating the contract of
118   * Throwable.getCause(), this returns null if <code>detail == this</code>,
119   * as no exception can be its own cause.
120   *
121   * @return the cause
122   * @since 1.4
123   */
124  public Throwable getCause()
125  {
126    return detail == this ? null : detail;
127  }
128}