/*
 * Licensed to the Apache Software Foundation (ASF) under one
 * or more contributor license agreements. See the NOTICE file
 * distributed with this work for additional information
 * regarding copyright ownership. The ASF licenses this file
 * to you under the Apache License, Version 2.0 (the  "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */
/*
 * $Id: XPathException.java 468655 2006-10-28 07:12:06Z minchau $
 */
package org.apache.xpath;

import javax.xml.transform.TransformerException;

import org.w3c.dom.Node;

This class implements an exception object that all
XPath classes will throw in case of an error.  This class
extends TransformerException, 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.
@xsl.usage
general/**
 * This class implements an exception object that all
 * XPath classes will throw in case of an error.  This class
 * extends TransformerException, 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.
 * @xsl.usage general
 */
public class XPathException extends TransformerException
{
    static final long serialVersionUID = 4263549717619045963L;

  
The home of the expression that caused the error.
 @serial  /** The home of the expression that caused the error.
   *  @serial  */
  Object m_styleNode = null;

  
Get the stylesheet node from where this error originated.
Returns:
The stylesheet node from where this error originated, or 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;
  }
  
  
Set the stylesheet node from where this error originated.
Params:
styleNode – The stylesheet node from where this error originated, or null./**
   * Set the stylesheet node from where this error originated.
   * @param styleNode The stylesheet node from where this error originated, or null.
   */
  public void setStylesheetNode(Object styleNode)
  {
    m_styleNode = styleNode;
  }


  
A nested exception.
 @serial   /** A nested exception.
   *  @serial   */
  protected Exception m_exception;

  
Create an XPathException object that holds
an error message.
Params:
message – The error message./**
   * Create an XPathException object that holds
   * an error message.
   * @param message The error message.
   */
  public XPathException(String message, ExpressionNode ex)
  {
    super(message);
    this.setLocator(ex);
    setStylesheetNode(getStylesheetNode(ex));
  }
  
  
Create an XPathException object that holds
an error message.
Params:
message – The error message./**
   * Create an XPathException object that holds
   * an error message.
   * @param message The error message.
   */
  public XPathException(String message)
  {
    super(message);
  }

  
  
Get the XSLT ElemVariable that this sub-expression references.  In order for 
this to work, the SourceLocator must be the owning ElemTemplateElement.
Returns:
The dereference to the ElemVariable, or null if not found./**
   * Get the XSLT ElemVariable that this sub-expression references.  In order for 
   * this to work, the SourceLocator must be the owning ElemTemplateElement.
   * @return The dereference to the ElemVariable, or null if not found.
   */
  public org.w3c.dom.Node getStylesheetNode(ExpressionNode ex)
  {
  	
    ExpressionNode owner = getExpressionOwner(ex);

    if (null != owner && owner instanceof org.w3c.dom.Node)
    {
		return ((org.w3c.dom.Node)owner);
    }
    return null;

  }
  
  
Get the first non-Expression parent of this node.
Returns:
null or first ancestor that is not an Expression./**
   * Get the first non-Expression parent of this node.
   * @return null or first ancestor that is not an Expression.
   */
  protected ExpressionNode getExpressionOwner(ExpressionNode ex)
  {
  	ExpressionNode parent = ex.exprGetParent();
  	while((null != parent) && (parent instanceof Expression))
  		parent = parent.exprGetParent();
  	return parent;
  }



  
Create an XPathException object that holds
an error message and the stylesheet node that
the error originated from.
Params:
message – The error message.
styleNode – The stylesheet node that the error originated from./**
   * 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.
Params:
message – The error message.
styleNode – The stylesheet node that the error originated from.
e – The exception that caused this exception./**
   * 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.
Params:
message – The error message.
e – The exception that caused this exception./**
   * 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.
Params:
s – The stream where the dump will be sent to./**
   * 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){}

    Throwable exception = m_exception;

    for (int i = 0; (i < 10) && (null != exception); i++)
    {
      s.println("---------");
      exception.printStackTrace(s);

      if (exception instanceof TransformerException)
      {
        TransformerException se = (TransformerException) exception;
        Throwable 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./**
   * Find the most contained message.
   *
   * @return The error message of the originating exception.
   */
  public String getMessage()
  {

    String lastMessage = super.getMessage();
    Throwable exception = m_exception;

    while (null != exception)
    {
      String nextMessage = exception.getMessage();

      if (null != nextMessage)
        lastMessage = nextMessage;

      if (exception instanceof TransformerException)
      {
        TransformerException se = (TransformerException) exception;
        Throwable 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.
Params:
s – The writer where the dump will be sent to./**
   * 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){}
    
    
    boolean isJdk14OrHigher = false;
    try {
        Throwable.class.getMethod("getCause",null);
        isJdk14OrHigher = true;
    } catch (NoSuchMethodException nsme) {
        // do nothing
    }
        
    // The printStackTrace method of the Throwable class in jdk 1.4 
    // and higher will include the cause when printing the backtrace.
    // The following code is only required when using jdk 1.3 or lower               
    if (!isJdk14OrHigher) {
    	        
      Throwable 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 TransformerException)
        {
          TransformerException se = (TransformerException) exception;
          Throwable prev = exception;

          exception = se.getException();

          if (prev == exception)
          {
            exception = null;

            break;
          }
        }
        else
        {
          exception = null;
        }
      }
    }
  }

  
 Return the embedded exception, if any.
 Overrides javax.xml.transform.TransformerException.getException().
 @return The embedded exception, or null if there is none.
/**
   *  Return the embedded exception, if any.
   *  Overrides javax.xml.transform.TransformerException.getException().
   * 
   *  @return The embedded exception, or null if there is none.
   */
  public Throwable getException()
  {
    return m_exception;
  }
}