/*
 * The Apache Software License, Version 1.1
 *
 *
 * Copyright (c) 1999 The Apache Software Foundation.  All rights 
 * reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 *
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer. 
 *
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in
 *    the documentation and/or other materials provided with the
 *    distribution.
 *
 * 3. The end-user documentation included with the redistribution,
 *    if any, must include the following acknowledgment:  
 *       "This product includes software developed by the
 *        Apache Software Foundation (http://www.apache.org/)."
 *    Alternately, this acknowledgment may appear in the software itself,
 *    if and wherever such third-party acknowledgments normally appear.
 *
 * 4. The names "Xalan" and "Apache Software Foundation" must
 *    not be used to endorse or promote products derived from this
 *    software without prior written permission. For written 
 *    permission, please contact apache@apache.org.
 *
 * 5. Products derived from this software may not be called "Apache",
 *    nor may "Apache" appear in their name, without prior written
 *    permission of the Apache Software Foundation.
 *
 * THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESSED OR IMPLIED
 * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
 * DISCLAIMED.  IN NO EVENT SHALL THE APACHE SOFTWARE FOUNDATION OR
 * ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
 * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF
 * USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
 * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
 * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
 * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 * SUCH DAMAGE.
 * ====================================================================
 *
 * This software consists of voluntary contributions made by many
 * individuals on behalf of the Apache Software Foundation and was
 * originally based on software copyright (c) 1999, Lotus
 * Development Corporation., http://www.lotus.com.  For more
 * information on the Apache Software Foundation, please see
 * <http://www.apache.org/>.
 */
package org.apache.xalan.xpath;
import org.w3c.dom.Node;
import org.xml.sax.SAXException;

/**
 * <meta name="usage" content="general"/>
 * This class implements an exception object that all 
 * XPath classes will throw in case of an error.  This class
 * extends SAXException, and may hold other exceptions. In the 
 * case of nested exceptions, printStackTrace will dump 
 * all the traces of the nested exceptions, not just the trace 
 * of this object.
 */
public class XPathException extends SAXException
{
  Object m_styleNode = null;
  
  /**
   * Get the stylesheet node from where this error originated.
   * @return The stylesheet node from where this error originated, or null.
   */
  public Object getStylesheetNode()
  {
    return m_styleNode;
  }
  
  protected Exception m_exception;
  
  /**
   * Create an XPathException object that holds 
   * an error message.
   * @param message The error message.
   */
  public XPathException(String message) 
  {
    super(message);
  }
  
  /**
   * Create an XPathException object that holds 
   * an error message and the stylesheet node that
   * the error originated from.
   * @param message The error message.
   * @param styleNode The stylesheet node that the error originated from.
   */
  public XPathException(String message, Object styleNode) 
  {
    super(message);
    m_styleNode = styleNode;
  }

  /**
   * Create an XPathException object that holds 
   * an error message, the stylesheet node that
   * the error originated from, and another exception 
   * that caused this exception.
   * @param message The error message.
   * @param styleNode The stylesheet node that the error originated from.
   * @param e The exception that caused this exception.
   */
  public XPathException (String message, Node styleNode, Exception e)
  {
    super(message);
    m_styleNode = styleNode;
    this.m_exception = e;
  }

  /**
   * Create an XPathException object that holds 
   * an error message, and another exception 
   * that caused this exception.
   * @param message The error message.
   * @param e The exception that caused this exception.
   */
  public XPathException (String message, Exception e)
  {
    super(message);
    this.m_exception = e;
  }
  
  /**
   * Print the the trace of methods from where the error 
   * originated.  This will trace all nested exception 
   * objects, as well as this object.
   * @param s The stream where the dump will be sent to.
   */
  public void printStackTrace(java.io.PrintStream s) 
  {
    if(s == null)
      s = System.err;
    try
    {
      super.printStackTrace(s);
    }
    catch(Exception e){}
    Exception exception = m_exception;
    for(int i = 0; (i < 10) && (null != exception); i++)
    {
      s.println("---------");
      exception.printStackTrace(s);
      if(exception instanceof SAXException)
      {
        SAXException se = (SAXException)exception;
        Exception prev = exception;
        exception = se.getException();
        if(prev == exception)
          break;
      }
      else
      {
        exception = null;
      }
    }
  }
  
  /**
   * Find the most contained message.
   * @returns The error message of the originating exception.
   */
  public String getMessage() 
  {
    String lastMessage = super.getMessage();
    Exception exception = m_exception;
    while(null != exception)
    {
      String nextMessage = exception.getMessage();
      if(null != nextMessage)
        lastMessage = nextMessage;
      if(exception instanceof SAXException)
      {
        SAXException se = (SAXException)exception;
        Exception prev = exception;
        exception = se.getException();
        if(prev == exception)
          break;
      }
      else
      {
        exception = null;
      }
    }
    return (null != lastMessage) ? lastMessage : "";
  }

  /**
   * Print the the trace of methods from where the error 
   * originated.  This will trace all nested exception 
   * objects, as well as this object.
   * @param s The writer where the dump will be sent to.
   */
  public void printStackTrace(java.io.PrintWriter s) 
  {
    if(s == null)
      s = new java.io.PrintWriter(System.err);
    try
    {
      super.printStackTrace(s);
    }
    catch(Exception e){}
    Exception exception = m_exception;
    
    for(int i = 0; (i < 10) && (null != exception); i++)
    {
      s.println("---------");
      try
      {
        exception.printStackTrace(s);
      }
      catch(Exception e)
      {
        s.println("Could not print stack trace...");
      }
      if(exception instanceof SAXException)
      {
        SAXException se = (SAXException)exception;
        Exception prev = exception;
        exception = se.getException();
        if(prev == exception)
        {
          exception = null;
          break;
        }
      }
      else
      {
        exception = null;
      }
    }
  }

  /**
    * Return the embedded exception, if any.
    * Overrides org.xml.sax.SAXException.getException().
    *
    * @return The embedded exception, or null if there is none.
    */
  public Exception getException ()
  {
    return m_exception;
  }

}