code: /*
   * 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.
   */
  /*
   * $Id$
   */
  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
   */
  public class XPathException extends TransformerException
  {
      static final long serialVersionUID = 4263549717619045963L;
  
    /** The home of the expression that caused the error.
     *  @serial  */
    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;
    }
    
    /**
     * 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   */
    protected Exception m_exception;
  
    /**
     * 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.
     * @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.
     * @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.
     * @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.
     * @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){}
  
      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.
     *
     * @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.
     * @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.
     */
    public Throwable getException()
    {
      return m_exception;
    }
  }
  