1 /*
   2  * Copyright (c) 2000, 2005, Oracle and/or its affiliates. All rights reserved.
   3  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
   4  *
   5  * This code is free software; you can redistribute it and/or modify it
   6  * under the terms of the GNU General Public License version 2 only, as
   7  * published by the Free Software Foundation.  Oracle designates this
   8  * particular file as subject to the "Classpath" exception as provided
   9  * by Oracle in the LICENSE file that accompanied this code.
  10  *
  11  * This code is distributed in the hope that it will be useful, but WITHOUT
  12  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
  13  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
  14  * version 2 for more details (a copy is included in the LICENSE file that
  15  * accompanied this code).
  16  *
  17  * You should have received a copy of the GNU General Public License version
  18  * 2 along with this work; if not, write to the Free Software Foundation,
  19  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
  20  *
  21  * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
  22  * or visit www.oracle.com if you need additional information or have any
  23  * questions.
  24  */
  25 
  26 // SAX error handler.
  27 // http://www.saxproject.org
  28 // No warranty; no copyright -- use this as you will.
  29 // $Id: ErrorHandler.java,v 1.2 2004/11/03 22:44:52 jsuttor Exp $
  30 
  31 package org.xml.sax;
  32 
  33 
  34 /**
  35  * Basic interface for SAX error handlers.
  36  *
  37  * <blockquote>
  38  * <em>This module, both source code and documentation, is in the
  39  * Public Domain, and comes with <strong>NO WARRANTY</strong>.</em>
  40  * See <a href='http://www.saxproject.org'>http://www.saxproject.org</a>
  41  * for further information.
  42  * </blockquote>
  43  *
  44  * <p>If a SAX application needs to implement customized error
  45  * handling, it must implement this interface and then register an
  46  * instance with the XML reader using the
  47  * {@link org.xml.sax.XMLReader#setErrorHandler setErrorHandler}
  48  * method.  The parser will then report all errors and warnings
  49  * through this interface.</p>
  50  *
  51  * <p><strong>WARNING:</strong> If an application does <em>not</em>
  52  * register an ErrorHandler, XML parsing errors will go unreported,
  53  * except that <em>SAXParseException</em>s will be thrown for fatal errors.
  54  * In order to detect validity errors, an ErrorHandler that does something
  55  * with {@link #error error()} calls must be registered.</p>
  56  *
  57  * <p>For XML processing errors, a SAX driver must use this interface
  58  * in preference to throwing an exception: it is up to the application
  59  * to decide whether to throw an exception for different types of
  60  * errors and warnings.  Note, however, that there is no requirement that
  61  * the parser continue to report additional errors after a call to
  62  * {@link #fatalError fatalError}.  In other words, a SAX driver class
  63  * may throw an exception after reporting any fatalError.
  64  * Also parsers may throw appropriate exceptions for non-XML errors.
  65  * For example, {@link XMLReader#parse XMLReader.parse()} would throw
  66  * an IOException for errors accessing entities or the document.</p>
  67  *
  68  * @since 1.4, SAX 1.0
  69  * @author David Megginson
  70  * @see org.xml.sax.XMLReader#setErrorHandler
  71  * @see org.xml.sax.SAXParseException
  72  */
  73 public interface ErrorHandler {
  74 
  75 
  76     /**
  77      * Receive notification of a warning.
  78      *
  79      * <p>SAX parsers will use this method to report conditions that
  80      * are not errors or fatal errors as defined by the XML
  81      * recommendation.  The default behaviour is to take no
  82      * action.</p>
  83      *
  84      * <p>The SAX parser must continue to provide normal parsing events
  85      * after invoking this method: it should still be possible for the
  86      * application to process the document through to the end.</p>
  87      *
  88      * <p>Filters may use this method to report other, non-XML warnings
  89      * as well.</p>
  90      *
  91      * @param exception The warning information encapsulated in a
  92      *                  SAX parse exception.
  93      * @exception org.xml.sax.SAXException Any SAX exception, possibly
  94      *            wrapping another exception.
  95      * @see org.xml.sax.SAXParseException
  96      */
  97     public abstract void warning (SAXParseException exception)
  98         throws SAXException;
  99 
 100 
 101     /**
 102      * Receive notification of a recoverable error.
 103      *
 104      * <p>This corresponds to the definition of "error" in section 1.2
 105      * of the W3C XML 1.0 Recommendation.  For example, a validating
 106      * parser would use this callback to report the violation of a
 107      * validity constraint.  The default behaviour is to take no
 108      * action.</p>
 109      *
 110      * <p>The SAX parser must continue to provide normal parsing
 111      * events after invoking this method: it should still be possible
 112      * for the application to process the document through to the end.
 113      * If the application cannot do so, then the parser should report
 114      * a fatal error even if the XML recommendation does not require
 115      * it to do so.</p>
 116      *
 117      * <p>Filters may use this method to report other, non-XML errors
 118      * as well.</p>
 119      *
 120      * @param exception The error information encapsulated in a
 121      *                  SAX parse exception.
 122      * @exception org.xml.sax.SAXException Any SAX exception, possibly
 123      *            wrapping another exception.
 124      * @see org.xml.sax.SAXParseException
 125      */
 126     public abstract void error (SAXParseException exception)
 127         throws SAXException;
 128 
 129 
 130     /**
 131      * Receive notification of a non-recoverable error.
 132      *
 133      * <p><strong>There is an apparent contradiction between the
 134      * documentation for this method and the documentation for {@link
 135      * org.xml.sax.ContentHandler#endDocument}.  Until this ambiguity
 136      * is resolved in a future major release, clients should make no
 137      * assumptions about whether endDocument() will or will not be
 138      * invoked when the parser has reported a fatalError() or thrown
 139      * an exception.</strong></p>
 140      *
 141      * <p>This corresponds to the definition of "fatal error" in
 142      * section 1.2 of the W3C XML 1.0 Recommendation.  For example, a
 143      * parser would use this callback to report the violation of a
 144      * well-formedness constraint.</p>
 145      *
 146      * <p>The application must assume that the document is unusable
 147      * after the parser has invoked this method, and should continue
 148      * (if at all) only for the sake of collecting additional error
 149      * messages: in fact, SAX parsers are free to stop reporting any
 150      * other events once this method has been invoked.</p>
 151      *
 152      * @param exception The error information encapsulated in a
 153      *                  SAX parse exception.
 154      * @exception org.xml.sax.SAXException Any SAX exception, possibly
 155      *            wrapping another exception.
 156      * @see org.xml.sax.SAXParseException
 157      */
 158     public abstract void fatalError (SAXParseException exception)
 159         throws SAXException;
 160 
 161 }
 162 
 163 // end of ErrorHandler.java