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    
005    This file is part of GNU Classpath.
006    
007    GNU Classpath is free software; you can redistribute it and/or modify
008    it under the terms of the GNU General Public License as published by
009    the Free Software Foundation; either version 2, or (at your option)
010    any later version.
011    
012    GNU Classpath is distributed in the hope that it will be useful, but
013    WITHOUT ANY WARRANTY; without even the implied warranty of
014    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
015    General Public License for more details.
016    
017    You should have received a copy of the GNU General Public License
018    along with GNU Classpath; see the file COPYING.  If not, write to the
019    Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
020    02110-1301 USA.
021    
022    Linking this library statically or dynamically with other modules is
023    making a combined work based on this library.  Thus, the terms and
024    conditions of the GNU General Public License cover the whole
025    combination.
026    
027    As a special exception, the copyright holders of this library give you
028    permission to link this library with independent modules to produce an
029    executable, regardless of the license terms of these independent
030    modules, and to copy and distribute the resulting executable under
031    terms of your choice, provided that you also meet, for each linked
032    independent module, the terms and conditions of the license of that
033    module.  An independent module is a module which is not derived from
034    or based on this library.  If you modify this library, you may extend
035    this exception to your version of the library, but you are not
036    obligated to do so.  If you do not wish to do so, delete this
037    exception statement from your version. */
038    
039    package java.rmi;
040    
041    import 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     */
052    public 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    }