http://xml.apache.org/commons/components/external/: xml-commons provides an Apache-hosted set of DOM, SAX, and JAXP interfaces for use in other xml-based projects. Our hope is that we can standardize on both a common version and packaging scheme for these critical XML standards interfaces to make the lives of both our developers and users easier. The External Components portion of xml-commons contains interfaces that are defined by external standards organizations. For DOM, that's the W3C; for SAX it's David Megginson and sax.sourceforge.net; for JAXP it's Sun. 
/*
 * Copyright (c) 1999 World Wide Web Consortium
 * (Massachusetts Institute of Technology, Institut National de Recherche
 *  en Informatique et en Automatique, Keio University).
 * All Rights Reserved. http://www.w3.org/Consortium/Legal/
 *
 * The original version of this interface comes from SAX :
 * http://www.megginson.com/SAX/
 *
 * $Id: ErrorHandler.java 477010 2006-11-20 02:54:38Z mrglavas $
 */
package org.w3c.css.sac;


Basic interface for CSS error handlers.

If a CSS application needs to implement customized error
handling, it must implement this interface and then register an
instance with the CSS parser using the parser's setErrorHandler
method.  The parser will then report all errors and warnings
through this interface.


 The parser shall use this interface instead of throwing an
exception: it is up to the application whether to throw an
exception for different types of errors and warnings.  Note,
however, that there is no requirement that the parser continue to
provide useful information after a call to fatalError (in other
words, a CSS driver class could catch an exception and report a
fatalError).


The HandlerBase class provides a default implementation of this
interface, ignoring warnings and recoverable errors and throwing a
SAXParseException for fatal errors.  An application may extend
that class rather than implementing the complete interface
itself.


Author: Philippe Le Hegaret
Version:$Revision: 477010 $
/**
  * Basic interface for CSS error handlers.
  *
  * <p>If a CSS application needs to implement customized error
  * handling, it must implement this interface and then register an
  * instance with the CSS parser using the parser's setErrorHandler
  * method.  The parser will then report all errors and warnings
  * through this interface.</p>
  *
  * <p> The parser shall use this interface instead of throwing an
  * exception: it is up to the application whether to throw an
  * exception for different types of errors and warnings.  Note,
  * however, that there is no requirement that the parser continue to
  * provide useful information after a call to fatalError (in other
  * words, a CSS driver class could catch an exception and report a
  * fatalError).</p>
  *
  * <p>The HandlerBase class provides a default implementation of this
  * interface, ignoring warnings and recoverable errors and throwing a
  * SAXParseException for fatal errors.  An application may extend
  * that class rather than implementing the complete interface
  * itself.</p>
  *
 * @version $Revision: 477010 $
 * @author  Philippe Le Hegaret
  */
public interface ErrorHandler {


  
Receive notification of a warning.

CSS parsers will use this method to report conditions that
are not errors or fatal errors as defined by the XML 1.0
recommendation.  The default behaviour is to take no action.


The CSS parser must continue to provide normal parsing events
after invoking this method: it should still be possible for the
application to process the document through to the end.


Params:
  • exception – The warning information encapsulated in a
                 CSS parse exception.
Throws:
  • CSSException – Any CSS exception, possibly
           wrapping another exception.
See Also:
/**
    * Receive notification of a warning.
    *
    * <p>CSS parsers will use this method to report conditions that
    * are not errors or fatal errors as defined by the XML 1.0
    * recommendation.  The default behaviour is to take no action.</p>
    *
    * <p>The CSS parser must continue to provide normal parsing events
    * after invoking this method: it should still be possible for the
    * application to process the document through to the end.</p>
    *
    * @param exception The warning information encapsulated in a
    *                  CSS parse exception.
    * @exception CSSException Any CSS exception, possibly
    *            wrapping another exception.
    * @see CSSParseException 
    */
  public void warning(CSSParseException exception) throws CSSException;

  
Receive notification of a recoverable error.

This corresponds to the definition of "error" in section 1.2
of the W3C XML 1.0 Recommendation.  For example, a validating
parser would use this callback to report the violation of a
validity constraint.  The default behaviour is to take no
action.


The CSS parser must continue to provide normal parsing events
after invoking this method: it should still be possible for the
application to process the document through to the end.  If the
application cannot do so, then the parser should report a fatal
error even if the XML 1.0 recommendation does not require it to
do so.


Params:
  • exception – The error information encapsulated in a
                 CSS parse exception.
Throws:
  • CSSException – Any CSS exception, possibly
           wrapping another exception.
See Also:
/**
    * Receive notification of a recoverable error.
    *
    * <p>This corresponds to the definition of "error" in section 1.2
    * of the W3C XML 1.0 Recommendation.  For example, a validating
    * parser would use this callback to report the violation of a
    * validity constraint.  The default behaviour is to take no
    * action.</p>
    *
    * <p>The CSS parser must continue to provide normal parsing events
    * after invoking this method: it should still be possible for the
    * application to process the document through to the end.  If the
    * application cannot do so, then the parser should report a fatal
    * error even if the XML 1.0 recommendation does not require it to
    * do so.</p>
    *
    * @param exception The error information encapsulated in a
    *                  CSS parse exception.
    * @exception CSSException Any CSS exception, possibly
    *            wrapping another exception.
    * @see CSSParseException 
    */
  public void error(CSSParseException exception) throws CSSException;

  
Receive notification of a non-recoverable error.

This corresponds to the definition of "fatal error" in
section 1.2 of the W3C XML 1.0 Recommendation.  For example, a
parser would use this callback to report the violation of a
well-formedness constraint.


The application must assume that the document is unusable
after the parser has invoked this method, and should continue
(if at all) only for the sake of collecting addition error
messages: in fact, CSS parsers are free to stop reporting any
other events once this method has been invoked.


Params:
  • exception – The error information encapsulated in a
                 CSS parse exception.
Throws:
  • CSSException – Any CSS exception, possibly
           wrapping another exception.
See Also:
/**
    * Receive notification of a non-recoverable error.
    *
    * <p>This corresponds to the definition of "fatal error" in
    * section 1.2 of the W3C XML 1.0 Recommendation.  For example, a
    * parser would use this callback to report the violation of a
    * well-formedness constraint.</p>
    *
    * <p>The application must assume that the document is unusable
    * after the parser has invoked this method, and should continue
    * (if at all) only for the sake of collecting addition error
    * messages: in fact, CSS parsers are free to stop reporting any
    * other events once this method has been invoked.</p>
    *
    * @param exception The error information encapsulated in a
    *                  CSS parse exception.  
    * @exception CSSException Any CSS exception, possibly
    *            wrapping another exception.
    * @see CSSParseException
    */
  public void fatalError(CSSParseException exception) throws CSSException;

}