/*
 * Copyright 2000-2005 Sun Microsystems, Inc.  All Rights Reserved.
 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
 *
 * This code is free software; you can redistribute it and/or modify it
 * under the terms of the GNU General Public License version 2 only, as
 * published by the Free Software Foundation.  Sun designates this
 * particular file as subject to the "Classpath" exception as provided
 * by Sun in the LICENSE file that accompanied this code.
 *
 * This code is distributed in the hope that it will be useful, but WITHOUT
 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
 * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
 * version 2 for more details (a copy is included in the LICENSE file that
 * accompanied this code).
 *
 * You should have received a copy of the GNU General Public License version
 * 2 along with this work; if not, write to the Free Software Foundation,
 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
 *
 * Please contact Sun Microsystems, Inc., 4150 Network Circle, Santa Clara,
 * CA 95054 USA or visit www.sun.com if you need additional information or
 * have any questions.
 */

// SAX exception class.
// http://www.saxproject.org
// No warranty; no copyright -- use this as you will.
// $Id: SAXException.java,v 1.3 2004/11/03 22:55:32 jsuttor Exp $

package org.xml.sax;

/**
 * Encapsulate a general SAX error or warning.
 *
 * <blockquote>
 * <em>This module, both source code and documentation, is in the
 * Public Domain, and comes with <strong>NO WARRANTY</strong>.</em>
 * See <a href='http://www.saxproject.org'>http://www.saxproject.org</a>
 * for further information.
 * </blockquote>
 *
 * <p>This class can contain basic error or warning information from
 * either the XML parser or the application: a parser writer or
 * application writer can subclass it to provide additional
 * functionality.  SAX handlers may throw this exception or
 * any exception subclassed from it.</p>
 *
 * <p>If the application needs to pass through other types of
 * exceptions, it must wrap those exceptions in a SAXException
 * or an exception derived from a SAXException.</p>
 *
 * <p>If the parser or application needs to include information about a
 * specific location in an XML document, it should use the
 * {@link org.xml.sax.SAXParseException SAXParseException} subclass.</p>
 *
 * @since SAX 1.0
 * @author David Megginson
 * @version 2.0.1 (sax2r2)
 * @see org.xml.sax.SAXParseException
 */
public class SAXException extends Exception {


    /**
     * Create a new SAXException.
     */
    public SAXException ()
    {
	super();
	this.exception = null;
    }
    
    
    /**
     * Create a new SAXException.
     *
     * @param message The error or warning message.
     */
    public SAXException (String message) {
	super(message);
	this.exception = null;
    }
    
    
    /**
     * Create a new SAXException wrapping an existing exception.
     *
     * <p>The existing exception will be embedded in the new
     * one, and its message will become the default message for
     * the SAXException.</p>
     *
     * @param e The exception to be wrapped in a SAXException.
     */
    public SAXException (Exception e)
    {
	super();
	this.exception = e;
    }
    
    
    /**
     * Create a new SAXException from an existing exception.
     *
     * <p>The existing exception will be embedded in the new
     * one, but the new exception will have its own message.</p>
     *
     * @param message The detail message.
     * @param e The exception to be wrapped in a SAXException.
     */
    public SAXException (String message, Exception e)
    {
	super(message);
	this.exception = e;
    }
    
    
    /**
     * Return a detail message for this exception.
     *
     * <p>If there is an embedded exception, and if the SAXException
     * has no detail message of its own, this method will return
     * the detail message from the embedded exception.</p>
     *
     * @return The error or warning message.
     */
    public String getMessage ()
    {
	String message = super.getMessage();
	
	if (message == null && exception != null) {
	    return exception.getMessage();
	} else {
	    return message;
	}
    }
    
    
    /**
     * Return the embedded exception, if any.
     *
     * @return The embedded exception, or null if there is none.
     */
    public Exception getException ()
    {
	return exception;
    }

    /**
     * Return the cause of the exception
     *
     * @return Return the cause of the exception
     */
    public Throwable getCause() {
        return exception;
    }

    /**
     * Override toString to pick up any embedded exception.
     *
     * @return A string representation of this exception.
     */
    public String toString ()
    {
	if (exception != null) {
	    return super.toString() + "\n" + exception.toString();
	} else {
	    return super.toString();
	}
    }
    
    
    
    //////////////////////////////////////////////////////////////////////
    // Internal state.
    //////////////////////////////////////////////////////////////////////


    /**
     * @serial The embedded exception if tunnelling, or null.
     */    
    private Exception exception;
    
    // Added serialVersionUID to preserve binary compatibility 
    static final long serialVersionUID = 583241635256073760L;
}

// end of SAXException.java
