luni/src/main/java/org/xml/sax/helpers/XMLFilterImpl.java - platform/libcore2 - Git at Google

 // XMLFilterImpl.java - base SAX2 filter implementation.
 // http://www.saxproject.org
 // Written by David Megginson
 // NO WARRANTY!  This class is in the Public Domain.
 // $Id: XMLFilterImpl.java,v 1.9 2004/04/26 17:34:35 dmegginson Exp $

 package org.xml.sax.helpers;

 import java.io.IOException;
 import org.xml.sax.Attributes;
 import org.xml.sax.ContentHandler;
 import org.xml.sax.DTDHandler;
 import org.xml.sax.EntityResolver;
 import org.xml.sax.ErrorHandler;
 import org.xml.sax.InputSource;
 import org.xml.sax.Locator;
 import org.xml.sax.SAXException;
 import org.xml.sax.SAXNotRecognizedException;
 import org.xml.sax.SAXNotSupportedException;
 import org.xml.sax.SAXParseException;
 import org.xml.sax.XMLFilter;
 import org.xml.sax.XMLReader;


 /**
  * Base class for deriving an XML filter.
  *
  * <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 is designed to sit between an {@link org.xml.sax.XMLReader
  * XMLReader} and the client application's event handlers.  By default, it
  * does nothing but pass requests up to the reader and events
  * on to the handlers unmodified, but subclasses can override
  * specific methods to modify the event stream or the configuration
  * requests as they pass through.</p>
  *
  * @since SAX 2.0
  * @author David Megginson
  * @version 2.0.1 (sax2r2)
  * @see org.xml.sax.XMLFilter
  * @see org.xml.sax.XMLReader
  * @see org.xml.sax.EntityResolver
  * @see org.xml.sax.DTDHandler
  * @see org.xml.sax.ContentHandler
  * @see org.xml.sax.ErrorHandler
  */
 public class XMLFilterImpl
     implements XMLFilter, EntityResolver, DTDHandler, ContentHandler, ErrorHandler
 {


     ////////////////////////////////////////////////////////////////////
     // Constructors.
     ////////////////////////////////////////////////////////////////////


     /**
      * Construct an empty XML filter, with no parent.
      *
      * <p>This filter will have no parent: you must assign a parent
      * before you start a parse or do any configuration with
      * setFeature or setProperty, unless you use this as a pure event
      * consumer rather than as an {@link XMLReader}.</p>
      *
      * @see org.xml.sax.XMLReader#setFeature
      * @see org.xml.sax.XMLReader#setProperty
      * @see #setParent
      */
     public XMLFilterImpl ()
     {
     }


     /**
      * Construct an XML filter with the specified parent.
      *
      * @param parent the XML reader from which this filter receives its events.
      *
      * @see #setParent
      * @see #getParent
      */
     public XMLFilterImpl (XMLReader parent)
     {
     setParent(parent);
     }


     ////////////////////////////////////////////////////////////////////
     // Implementation of org.xml.sax.XMLFilter.
     ////////////////////////////////////////////////////////////////////


     /**
      * Set the parent reader.
      *
      * <p>This is the {@link org.xml.sax.XMLReader XMLReader} from which
      * this filter will obtain its events and to which it will pass its
      * configuration requests.  The parent may itself be another filter.</p>
      *
      * <p>If there is no parent reader set, any attempt to parse
      * or to set or get a feature or property will fail.</p>
      *
      * @param parent The parent XML reader.
      * @see #getParent
      */
     public void setParent (XMLReader parent)
     {
     this.parent = parent;
     }


     /**
      * Get the parent reader.
      *
      * @return The parent XML reader, or null if none is set.
      * @see #setParent
      */
     public XMLReader getParent ()
     {
     return parent;
     }


     ////////////////////////////////////////////////////////////////////
     // Implementation of org.xml.sax.XMLReader.
     ////////////////////////////////////////////////////////////////////


     /**
      * Set the value of a feature.
      *
      * <p>This will always fail if the parent is null.</p>
      *
      * @param name The feature name.
      * @param value The requested feature value.
      * @exception org.xml.sax.SAXNotRecognizedException If the feature
      *            value can't be assigned or retrieved from the parent.
      * @exception org.xml.sax.SAXNotSupportedException When the
      *            parent recognizes the feature name but
      *            cannot set the requested value.
      */
     public void setFeature (String name, boolean value)
     throws SAXNotRecognizedException, SAXNotSupportedException
     {
     if (parent != null) {
         parent.setFeature(name, value);
     } else {
         throw new SAXNotRecognizedException("Feature: " + name);
     }
     }


     /**
      * Look up the value of a feature.
      *
      * <p>This will always fail if the parent is null.</p>
      *
      * @param name The feature name.
      * @return The current value of the feature.
      * @exception org.xml.sax.SAXNotRecognizedException If the feature
      *            value can't be assigned or retrieved from the parent.
      * @exception org.xml.sax.SAXNotSupportedException When the
      *            parent recognizes the feature name but
      *            cannot determine its value at this time.
      */
     public boolean getFeature (String name)
     throws SAXNotRecognizedException, SAXNotSupportedException
     {
     if (parent != null) {
         return parent.getFeature(name);
     } else {
         throw new SAXNotRecognizedException("Feature: " + name);
     }
     }


     /**
      * Set the value of a property.
      *
      * <p>This will always fail if the parent is null.</p>
      *
      * @param name The property name.
      * @param value The requested property value.
      * @exception org.xml.sax.SAXNotRecognizedException If the property
      *            value can't be assigned or retrieved from the parent.
      * @exception org.xml.sax.SAXNotSupportedException When the
      *            parent recognizes the property name but
      *            cannot set the requested value.
      */
     public void setProperty (String name, Object value)
     throws SAXNotRecognizedException, SAXNotSupportedException
     {
     if (parent != null) {
         parent.setProperty(name, value);
     } else {
         throw new SAXNotRecognizedException("Property: " + name);
     }
     }


     /**
      * Look up the value of a property.
      *
      * @param name The property name.
      * @return The current value of the property.
      * @exception org.xml.sax.SAXNotRecognizedException If the property
      *            value can't be assigned or retrieved from the parent.
      * @exception org.xml.sax.SAXNotSupportedException When the
      *            parent recognizes the property name but
      *            cannot determine its value at this time.
      */
     public Object getProperty (String name)
     throws SAXNotRecognizedException, SAXNotSupportedException
     {
     if (parent != null) {
         return parent.getProperty(name);
     } else {
         throw new SAXNotRecognizedException("Property: " + name);
     }
     }


     /**
      * Set the entity resolver.
      *
      * @param resolver The new entity resolver.
      */
     public void setEntityResolver (EntityResolver resolver)
     {
     entityResolver = resolver;
     }


     /**
      * Get the current entity resolver.
      *
      * @return The current entity resolver, or null if none was set.
      */
     public EntityResolver getEntityResolver ()
     {
     return entityResolver;
     }


     /**
      * Set the DTD event handler.
      *
      * @param handler the new DTD handler
      */
     public void setDTDHandler (DTDHandler handler)
     {
     dtdHandler = handler;
     }


     /**
      * Get the current DTD event handler.
      *
      * @return The current DTD handler, or null if none was set.
      */
     public DTDHandler getDTDHandler ()
     {
     return dtdHandler;
     }


     /**
      * Set the content event handler.
      *
      * @param handler the new content handler
      */
     public void setContentHandler (ContentHandler handler)
     {
     contentHandler = handler;
     }


     /**
      * Get the content event handler.
      *
      * @return The current content handler, or null if none was set.
      */
     public ContentHandler getContentHandler ()
     {
     return contentHandler;
     }


     /**
      * Set the error event handler.
      *
      * @param handler the new error handler
      */
     public void setErrorHandler (ErrorHandler handler)
     {
     errorHandler = handler;
     }


     /**
      * Get the current error event handler.
      *
      * @return The current error handler, or null if none was set.
      */
     public ErrorHandler getErrorHandler ()
     {
     return errorHandler;
     }


     /**
      * Parse a document.
      *
      * @param input The input source for the document entity.
      * @exception org.xml.sax.SAXException Any SAX exception, possibly
      *            wrapping another exception.
      * @exception java.io.IOException An IO exception from the parser,
      *            possibly from a byte stream or character stream
      *            supplied by the application.
      */
     public void parse (InputSource input)
     throws SAXException, IOException
     {
     setupParse();
     parent.parse(input);
     }


     /**
      * Parse a document.
      *
      * @param systemId The system identifier as a fully-qualified URI.
      * @exception org.xml.sax.SAXException Any SAX exception, possibly
      *            wrapping another exception.
      * @exception java.io.IOException An IO exception from the parser,
      *            possibly from a byte stream or character stream
      *            supplied by the application.
      */
     public void parse (String systemId)
     throws SAXException, IOException
     {
     parse(new InputSource(systemId));
     }


     ////////////////////////////////////////////////////////////////////
     // Implementation of org.xml.sax.EntityResolver.
     ////////////////////////////////////////////////////////////////////


     /**
      * Filter an external entity resolution.
      *
      * @param publicId The entity's public identifier, or null.
      * @param systemId The entity's system identifier.
      * @return A new InputSource or null for the default.
      * @exception org.xml.sax.SAXException The client may throw
      *            an exception during processing.
      * @exception java.io.IOException The client may throw an
      *            I/O-related exception while obtaining the
      *            new InputSource.
      */
     public InputSource resolveEntity (String publicId, String systemId)
     throws SAXException, IOException
     {
     if (entityResolver != null) {
         return entityResolver.resolveEntity(publicId, systemId);
     } else {
         return null;
     }
     }


     ////////////////////////////////////////////////////////////////////
     // Implementation of org.xml.sax.DTDHandler.
     ////////////////////////////////////////////////////////////////////


     /**
      * Filter a notation declaration event.
      *
      * @param name The notation name.
      * @param publicId The notation's public identifier, or null.
      * @param systemId The notation's system identifier, or null.
      * @exception org.xml.sax.SAXException The client may throw
      *            an exception during processing.
      */
     public void notationDecl (String name, String publicId, String systemId)
     throws SAXException
     {
     if (dtdHandler != null) {
         dtdHandler.notationDecl(name, publicId, systemId);
     }
     }


     /**
      * Filter an unparsed entity declaration event.
      *
      * @param name The entity name.
      * @param publicId The entity's public identifier, or null.
      * @param systemId The entity's system identifier, or null.
      * @param notationName The name of the associated notation.
      * @exception org.xml.sax.SAXException The client may throw
      *            an exception during processing.
      */
     public void unparsedEntityDecl (String name, String publicId,
                     String systemId, String notationName)
     throws SAXException
     {
     if (dtdHandler != null) {
         dtdHandler.unparsedEntityDecl(name, publicId, systemId,
                       notationName);
     }
     }


     ////////////////////////////////////////////////////////////////////
     // Implementation of org.xml.sax.ContentHandler.
     ////////////////////////////////////////////////////////////////////


     /**
      * Filter a new document locator event.
      *
      * @param locator The document locator.
      */
     public void setDocumentLocator (Locator locator)
     {
     this.locator = locator;
     if (contentHandler != null) {
         contentHandler.setDocumentLocator(locator);
     }
     }


     /**
      * Filter a start document event.
      *
      * @exception org.xml.sax.SAXException The client may throw
      *            an exception during processing.
      */
     public void startDocument ()
     throws SAXException
     {
     if (contentHandler != null) {
         contentHandler.startDocument();
     }
     }


     /**
      * Filter an end document event.
      *
      * @exception org.xml.sax.SAXException The client may throw
      *            an exception during processing.
      */
     public void endDocument ()
     throws SAXException
     {
     if (contentHandler != null) {
         contentHandler.endDocument();
     }
     }


     /**
      * Filter a start Namespace prefix mapping event.
      *
      * @param prefix The Namespace prefix.
      * @param uri The Namespace URI.
      * @exception org.xml.sax.SAXException The client may throw
      *            an exception during processing.
      */
     public void startPrefixMapping (String prefix, String uri)
     throws SAXException
     {
     if (contentHandler != null) {
         contentHandler.startPrefixMapping(prefix, uri);
     }
     }


     /**
      * Filter an end Namespace prefix mapping event.
      *
      * @param prefix The Namespace prefix.
      * @exception org.xml.sax.SAXException The client may throw
      *            an exception during processing.
      */
     public void endPrefixMapping (String prefix)
     throws SAXException
     {
     if (contentHandler != null) {
         contentHandler.endPrefixMapping(prefix);
     }
     }


     /**
      * Filter a start element event.
      *
      * @param uri The element's Namespace URI, or the empty string.
      * @param localName The element's local name, or the empty string.
      * @param qName The element's qualified (prefixed) name, or the empty
      *        string.
      * @param atts The element's attributes.
      * @exception org.xml.sax.SAXException The client may throw
      *            an exception during processing.
      */
     public void startElement (String uri, String localName, String qName,
                   Attributes atts)
     throws SAXException
     {
     if (contentHandler != null) {
         contentHandler.startElement(uri, localName, qName, atts);
     }
     }


     /**
      * Filter an end element event.
      *
      * @param uri The element's Namespace URI, or the empty string.
      * @param localName The element's local name, or the empty string.
      * @param qName The element's qualified (prefixed) name, or the empty
      *        string.
      * @exception org.xml.sax.SAXException The client may throw
      *            an exception during processing.
      */
     public void endElement (String uri, String localName, String qName)
     throws SAXException
     {
     if (contentHandler != null) {
         contentHandler.endElement(uri, localName, qName);
     }
     }


     /**
      * Filter a character data event.
      *
      * @param ch An array of characters.
      * @param start The starting position in the array.
      * @param length The number of characters to use from the array.
      * @exception org.xml.sax.SAXException The client may throw
      *            an exception during processing.
      */
     public void characters (char ch[], int start, int length)
     throws SAXException
     {
     if (contentHandler != null) {
         contentHandler.characters(ch, start, length);
     }
     }


     /**
      * Filter an ignorable whitespace event.
      *
      * @param ch An array of characters.
      * @param start The starting position in the array.
      * @param length The number of characters to use from the array.
      * @exception org.xml.sax.SAXException The client may throw
      *            an exception during processing.
      */
     public void ignorableWhitespace (char ch[], int start, int length)
     throws SAXException
     {
     if (contentHandler != null) {
         contentHandler.ignorableWhitespace(ch, start, length);
     }
     }


     /**
      * Filter a processing instruction event.
      *
      * @param target The processing instruction target.
      * @param data The text following the target.
      * @exception org.xml.sax.SAXException The client may throw
      *            an exception during processing.
      */
     public void processingInstruction (String target, String data)
     throws SAXException
     {
     if (contentHandler != null) {
         contentHandler.processingInstruction(target, data);
     }
     }


     /**
      * Filter a skipped entity event.
      *
      * @param name The name of the skipped entity.
      * @exception org.xml.sax.SAXException The client may throw
      *            an exception during processing.
      */
     public void skippedEntity (String name)
     throws SAXException
     {
     if (contentHandler != null) {
         contentHandler.skippedEntity(name);
     }
     }


     ////////////////////////////////////////////////////////////////////
     // Implementation of org.xml.sax.ErrorHandler.
     ////////////////////////////////////////////////////////////////////


     /**
      * Filter a warning event.
      *
      * @param e The warning as an exception.
      * @exception org.xml.sax.SAXException The client may throw
      *            an exception during processing.
      */
     public void warning (SAXParseException e)
     throws SAXException
     {
     if (errorHandler != null) {
         errorHandler.warning(e);
     }
     }


     /**
      * Filter an error event.
      *
      * @param e The error as an exception.
      * @exception org.xml.sax.SAXException The client may throw
      *            an exception during processing.
      */
     public void error (SAXParseException e)
     throws SAXException
     {
     if (errorHandler != null) {
         errorHandler.error(e);
     }
     }


     /**
      * Filter a fatal error event.
      *
      * @param e The error as an exception.
      * @exception org.xml.sax.SAXException The client may throw
      *            an exception during processing.
      */
     public void fatalError (SAXParseException e)
     throws SAXException
     {
     if (errorHandler != null) {
         errorHandler.fatalError(e);
     }
     }


     ////////////////////////////////////////////////////////////////////
     // Internal methods.
     ////////////////////////////////////////////////////////////////////


     /**
      * Set up before a parse.
      *
      * <p>Before every parse, check whether the parent is
      * non-null, and re-register the filter for all of the
      * events.</p>
      */
     private void setupParse ()
     {
     if (parent == null) {
         throw new NullPointerException("No parent for filter");
     }
     parent.setEntityResolver(this);
     parent.setDTDHandler(this);
     parent.setContentHandler(this);
     parent.setErrorHandler(this);
     }


     ////////////////////////////////////////////////////////////////////
     // Internal state.
     ////////////////////////////////////////////////////////////////////

     private XMLReader parent = null;
     private Locator locator = null;
     private EntityResolver entityResolver = null;
     private DTDHandler dtdHandler = null;
     private ContentHandler contentHandler = null;
     private ErrorHandler errorHandler = null;

 }

 // end of XMLFilterImpl.java
	// XMLFilterImpl.java - base SAX2 filter implementation.
	// http://www.saxproject.org
	// Written by David Megginson
	// NO WARRANTY! This class is in the Public Domain.
	// $Id: XMLFilterImpl.java,v 1.9 2004/04/26 17:34:35 dmegginson Exp $

	package org.xml.sax.helpers;

	import java.io.IOException;
	import org.xml.sax.Attributes;
	import org.xml.sax.ContentHandler;
	import org.xml.sax.DTDHandler;
	import org.xml.sax.EntityResolver;
	import org.xml.sax.ErrorHandler;
	import org.xml.sax.InputSource;
	import org.xml.sax.Locator;
	import org.xml.sax.SAXException;
	import org.xml.sax.SAXNotRecognizedException;
	import org.xml.sax.SAXNotSupportedException;
	import org.xml.sax.SAXParseException;
	import org.xml.sax.XMLFilter;
	import org.xml.sax.XMLReader;


	/**
	* Base class for deriving an XML filter.
	*
	* <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 is designed to sit between an {@link org.xml.sax.XMLReader
	* XMLReader} and the client application's event handlers. By default, it
	* does nothing but pass requests up to the reader and events
	* on to the handlers unmodified, but subclasses can override
	* specific methods to modify the event stream or the configuration
	* requests as they pass through.</p>
	*
	* @since SAX 2.0
	* @author David Megginson
	* @version 2.0.1 (sax2r2)
	* @see org.xml.sax.XMLFilter
	* @see org.xml.sax.XMLReader
	* @see org.xml.sax.EntityResolver
	* @see org.xml.sax.DTDHandler
	* @see org.xml.sax.ContentHandler
	* @see org.xml.sax.ErrorHandler
	*/
	public class XMLFilterImpl
	implements XMLFilter, EntityResolver, DTDHandler, ContentHandler, ErrorHandler
	{


	////////////////////////////////////////////////////////////////////
	// Constructors.
	////////////////////////////////////////////////////////////////////


	/**
	* Construct an empty XML filter, with no parent.
	*
	* <p>This filter will have no parent: you must assign a parent
	* before you start a parse or do any configuration with
	* setFeature or setProperty, unless you use this as a pure event
	* consumer rather than as an {@link XMLReader}.</p>
	*
	* @see org.xml.sax.XMLReader#setFeature
	* @see org.xml.sax.XMLReader#setProperty
	* @see #setParent
	*/
	public XMLFilterImpl ()
	{
	}


	/**
	* Construct an XML filter with the specified parent.
	*
	* @param parent the XML reader from which this filter receives its events.
	*
	* @see #setParent
	* @see #getParent
	*/
	public XMLFilterImpl (XMLReader parent)
	{
	setParent(parent);
	}



	////////////////////////////////////////////////////////////////////
	// Implementation of org.xml.sax.XMLFilter.
	////////////////////////////////////////////////////////////////////


	/**
	* Set the parent reader.
	*
	* <p>This is the {@link org.xml.sax.XMLReader XMLReader} from which
	* this filter will obtain its events and to which it will pass its
	* configuration requests. The parent may itself be another filter.</p>
	*
	* <p>If there is no parent reader set, any attempt to parse
	* or to set or get a feature or property will fail.</p>
	*
	* @param parent The parent XML reader.
	* @see #getParent
	*/
	public void setParent (XMLReader parent)
	{
	this.parent = parent;
	}


	/**
	* Get the parent reader.
	*
	* @return The parent XML reader, or null if none is set.
	* @see #setParent
	*/
	public XMLReader getParent ()
	{
	return parent;
	}



	////////////////////////////////////////////////////////////////////
	// Implementation of org.xml.sax.XMLReader.
	////////////////////////////////////////////////////////////////////


	/**
	* Set the value of a feature.
	*
	* <p>This will always fail if the parent is null.</p>
	*
	* @param name The feature name.
	* @param value The requested feature value.
	* @exception org.xml.sax.SAXNotRecognizedException If the feature
	* value can't be assigned or retrieved from the parent.
	* @exception org.xml.sax.SAXNotSupportedException When the
	* parent recognizes the feature name but
	* cannot set the requested value.
	*/
	public void setFeature (String name, boolean value)
	throws SAXNotRecognizedException, SAXNotSupportedException
	{
	if (parent != null) {
	parent.setFeature(name, value);
	} else {
	throw new SAXNotRecognizedException("Feature: " + name);
	}
	}


	/**
	* Look up the value of a feature.
	*
	* <p>This will always fail if the parent is null.</p>
	*
	* @param name The feature name.
	* @return The current value of the feature.
	* @exception org.xml.sax.SAXNotRecognizedException If the feature
	* value can't be assigned or retrieved from the parent.
	* @exception org.xml.sax.SAXNotSupportedException When the
	* parent recognizes the feature name but
	* cannot determine its value at this time.
	*/
	public boolean getFeature (String name)
	throws SAXNotRecognizedException, SAXNotSupportedException
	{
	if (parent != null) {
	return parent.getFeature(name);
	} else {
	throw new SAXNotRecognizedException("Feature: " + name);
	}
	}


	/**
	* Set the value of a property.
	*
	* <p>This will always fail if the parent is null.</p>
	*
	* @param name The property name.
	* @param value The requested property value.
	* @exception org.xml.sax.SAXNotRecognizedException If the property
	* value can't be assigned or retrieved from the parent.
	* @exception org.xml.sax.SAXNotSupportedException When the
	* parent recognizes the property name but
	* cannot set the requested value.
	*/
	public void setProperty (String name, Object value)
	throws SAXNotRecognizedException, SAXNotSupportedException
	{
	if (parent != null) {
	parent.setProperty(name, value);
	} else {
	throw new SAXNotRecognizedException("Property: " + name);
	}
	}


	/**
	* Look up the value of a property.
	*
	* @param name The property name.
	* @return The current value of the property.
	* @exception org.xml.sax.SAXNotRecognizedException If the property
	* value can't be assigned or retrieved from the parent.
	* @exception org.xml.sax.SAXNotSupportedException When the
	* parent recognizes the property name but
	* cannot determine its value at this time.
	*/
	public Object getProperty (String name)
	throws SAXNotRecognizedException, SAXNotSupportedException
	{
	if (parent != null) {
	return parent.getProperty(name);
	} else {
	throw new SAXNotRecognizedException("Property: " + name);
	}
	}


	/**
	* Set the entity resolver.
	*
	* @param resolver The new entity resolver.
	*/
	public void setEntityResolver (EntityResolver resolver)
	{
	entityResolver = resolver;
	}


	/**
	* Get the current entity resolver.
	*
	* @return The current entity resolver, or null if none was set.
	*/
	public EntityResolver getEntityResolver ()
	{
	return entityResolver;
	}


	/**
	* Set the DTD event handler.
	*
	* @param handler the new DTD handler
	*/
	public void setDTDHandler (DTDHandler handler)
	{
	dtdHandler = handler;
	}


	/**
	* Get the current DTD event handler.
	*
	* @return The current DTD handler, or null if none was set.
	*/
	public DTDHandler getDTDHandler ()
	{
	return dtdHandler;
	}


	/**
	* Set the content event handler.
	*
	* @param handler the new content handler
	*/
	public void setContentHandler (ContentHandler handler)
	{
	contentHandler = handler;
	}


	/**
	* Get the content event handler.
	*
	* @return The current content handler, or null if none was set.
	*/
	public ContentHandler getContentHandler ()
	{
	return contentHandler;
	}


	/**
	* Set the error event handler.
	*
	* @param handler the new error handler
	*/
	public void setErrorHandler (ErrorHandler handler)
	{
	errorHandler = handler;
	}


	/**
	* Get the current error event handler.
	*
	* @return The current error handler, or null if none was set.
	*/
	public ErrorHandler getErrorHandler ()
	{
	return errorHandler;
	}


	/**
	* Parse a document.
	*
	* @param input The input source for the document entity.
	* @exception org.xml.sax.SAXException Any SAX exception, possibly
	* wrapping another exception.
	* @exception java.io.IOException An IO exception from the parser,
	* possibly from a byte stream or character stream
	* supplied by the application.
	*/
	public void parse (InputSource input)
	throws SAXException, IOException
	{
	setupParse();
	parent.parse(input);
	}


	/**
	* Parse a document.
	*
	* @param systemId The system identifier as a fully-qualified URI.
	* @exception org.xml.sax.SAXException Any SAX exception, possibly
	* wrapping another exception.
	* @exception java.io.IOException An IO exception from the parser,
	* possibly from a byte stream or character stream
	* supplied by the application.
	*/
	public void parse (String systemId)
	throws SAXException, IOException
	{
	parse(new InputSource(systemId));
	}



	////////////////////////////////////////////////////////////////////
	// Implementation of org.xml.sax.EntityResolver.
	////////////////////////////////////////////////////////////////////


	/**
	* Filter an external entity resolution.
	*
	* @param publicId The entity's public identifier, or null.
	* @param systemId The entity's system identifier.
	* @return A new InputSource or null for the default.
	* @exception org.xml.sax.SAXException The client may throw
	* an exception during processing.
	* @exception java.io.IOException The client may throw an
	* I/O-related exception while obtaining the
	* new InputSource.
	*/
	public InputSource resolveEntity (String publicId, String systemId)
	throws SAXException, IOException
	{
	if (entityResolver != null) {
	return entityResolver.resolveEntity(publicId, systemId);
	} else {
	return null;
	}
	}



	////////////////////////////////////////////////////////////////////
	// Implementation of org.xml.sax.DTDHandler.
	////////////////////////////////////////////////////////////////////


	/**
	* Filter a notation declaration event.
	*
	* @param name The notation name.
	* @param publicId The notation's public identifier, or null.
	* @param systemId The notation's system identifier, or null.
	* @exception org.xml.sax.SAXException The client may throw
	* an exception during processing.
	*/
	public void notationDecl (String name, String publicId, String systemId)
	throws SAXException
	{
	if (dtdHandler != null) {
	dtdHandler.notationDecl(name, publicId, systemId);
	}
	}


	/**
	* Filter an unparsed entity declaration event.
	*
	* @param name The entity name.
	* @param publicId The entity's public identifier, or null.
	* @param systemId The entity's system identifier, or null.
	* @param notationName The name of the associated notation.
	* @exception org.xml.sax.SAXException The client may throw
	* an exception during processing.
	*/
	public void unparsedEntityDecl (String name, String publicId,
	String systemId, String notationName)
	throws SAXException
	{
	if (dtdHandler != null) {
	dtdHandler.unparsedEntityDecl(name, publicId, systemId,
	notationName);
	}
	}



	////////////////////////////////////////////////////////////////////
	// Implementation of org.xml.sax.ContentHandler.
	////////////////////////////////////////////////////////////////////


	/**
	* Filter a new document locator event.
	*
	* @param locator The document locator.
	*/
	public void setDocumentLocator (Locator locator)
	{
	this.locator = locator;
	if (contentHandler != null) {
	contentHandler.setDocumentLocator(locator);
	}
	}


	/**
	* Filter a start document event.
	*
	* @exception org.xml.sax.SAXException The client may throw
	* an exception during processing.
	*/
	public void startDocument ()
	throws SAXException
	{
	if (contentHandler != null) {
	contentHandler.startDocument();
	}
	}


	/**
	* Filter an end document event.
	*
	* @exception org.xml.sax.SAXException The client may throw
	* an exception during processing.
	*/
	public void endDocument ()
	throws SAXException
	{
	if (contentHandler != null) {
	contentHandler.endDocument();
	}
	}


	/**
	* Filter a start Namespace prefix mapping event.
	*
	* @param prefix The Namespace prefix.
	* @param uri The Namespace URI.
	* @exception org.xml.sax.SAXException The client may throw
	* an exception during processing.
	*/
	public void startPrefixMapping (String prefix, String uri)
	throws SAXException
	{
	if (contentHandler != null) {
	contentHandler.startPrefixMapping(prefix, uri);
	}
	}


	/**
	* Filter an end Namespace prefix mapping event.
	*
	* @param prefix The Namespace prefix.
	* @exception org.xml.sax.SAXException The client may throw
	* an exception during processing.
	*/
	public void endPrefixMapping (String prefix)
	throws SAXException
	{
	if (contentHandler != null) {
	contentHandler.endPrefixMapping(prefix);
	}
	}


	/**
	* Filter a start element event.
	*
	* @param uri The element's Namespace URI, or the empty string.
	* @param localName The element's local name, or the empty string.
	* @param qName The element's qualified (prefixed) name, or the empty
	* string.
	* @param atts The element's attributes.
	* @exception org.xml.sax.SAXException The client may throw
	* an exception during processing.
	*/
	public void startElement (String uri, String localName, String qName,
	Attributes atts)
	throws SAXException
	{
	if (contentHandler != null) {
	contentHandler.startElement(uri, localName, qName, atts);
	}
	}


	/**
	* Filter an end element event.
	*
	* @param uri The element's Namespace URI, or the empty string.
	* @param localName The element's local name, or the empty string.
	* @param qName The element's qualified (prefixed) name, or the empty
	* string.
	* @exception org.xml.sax.SAXException The client may throw
	* an exception during processing.
	*/
	public void endElement (String uri, String localName, String qName)
	throws SAXException
	{
	if (contentHandler != null) {
	contentHandler.endElement(uri, localName, qName);
	}
	}


	/**
	* Filter a character data event.
	*
	* @param ch An array of characters.
	* @param start The starting position in the array.
	* @param length The number of characters to use from the array.
	* @exception org.xml.sax.SAXException The client may throw
	* an exception during processing.
	*/
	public void characters (char ch[], int start, int length)
	throws SAXException
	{
	if (contentHandler != null) {
	contentHandler.characters(ch, start, length);
	}
	}


	/**
	* Filter an ignorable whitespace event.
	*
	* @param ch An array of characters.
	* @param start The starting position in the array.
	* @param length The number of characters to use from the array.
	* @exception org.xml.sax.SAXException The client may throw
	* an exception during processing.
	*/
	public void ignorableWhitespace (char ch[], int start, int length)
	throws SAXException
	{
	if (contentHandler != null) {
	contentHandler.ignorableWhitespace(ch, start, length);
	}
	}


	/**
	* Filter a processing instruction event.
	*
	* @param target The processing instruction target.
	* @param data The text following the target.
	* @exception org.xml.sax.SAXException The client may throw
	* an exception during processing.
	*/
	public void processingInstruction (String target, String data)
	throws SAXException
	{
	if (contentHandler != null) {
	contentHandler.processingInstruction(target, data);
	}
	}


	/**
	* Filter a skipped entity event.
	*
	* @param name The name of the skipped entity.
	* @exception org.xml.sax.SAXException The client may throw
	* an exception during processing.
	*/
	public void skippedEntity (String name)
	throws SAXException
	{
	if (contentHandler != null) {
	contentHandler.skippedEntity(name);
	}
	}



	////////////////////////////////////////////////////////////////////
	// Implementation of org.xml.sax.ErrorHandler.
	////////////////////////////////////////////////////////////////////


	/**
	* Filter a warning event.
	*
	* @param e The warning as an exception.
	* @exception org.xml.sax.SAXException The client may throw
	* an exception during processing.
	*/
	public void warning (SAXParseException e)
	throws SAXException
	{
	if (errorHandler != null) {
	errorHandler.warning(e);
	}
	}


	/**
	* Filter an error event.
	*
	* @param e The error as an exception.
	* @exception org.xml.sax.SAXException The client may throw
	* an exception during processing.
	*/
	public void error (SAXParseException e)
	throws SAXException
	{
	if (errorHandler != null) {
	errorHandler.error(e);
	}
	}


	/**
	* Filter a fatal error event.
	*
	* @param e The error as an exception.
	* @exception org.xml.sax.SAXException The client may throw
	* an exception during processing.
	*/
	public void fatalError (SAXParseException e)
	throws SAXException
	{
	if (errorHandler != null) {
	errorHandler.fatalError(e);
	}
	}



	////////////////////////////////////////////////////////////////////
	// Internal methods.
	////////////////////////////////////////////////////////////////////


	/**
	* Set up before a parse.
	*
	* <p>Before every parse, check whether the parent is
	* non-null, and re-register the filter for all of the
	* events.</p>
	*/
	private void setupParse ()
	{
	if (parent == null) {
	throw new NullPointerException("No parent for filter");
	}
	parent.setEntityResolver(this);
	parent.setDTDHandler(this);
	parent.setContentHandler(this);
	parent.setErrorHandler(this);
	}



	////////////////////////////////////////////////////////////////////
	// Internal state.
	////////////////////////////////////////////////////////////////////

	private XMLReader parent = null;
	private Locator locator = null;
	private EntityResolver entityResolver = null;
	private DTDHandler dtdHandler = null;
	private ContentHandler contentHandler = null;
	private ErrorHandler errorHandler = null;

	}

	// end of XMLFilterImpl.java