1 // SAX error handler.
2 // http://www.saxproject.org
3 // No warranty; no copyright -- use this as you will.
4 // $Id: ErrorHandler.java,v 1.10 2004/03/08 13:01:00 dmegginson Exp $
5 
6 package org.xml.sax;
7 
8 
9 /**
10  * Basic interface for SAX error handlers.
11  *
12  * <blockquote>
13  * <em>This module, both source code and documentation, is in the
14  * Public Domain, and comes with <strong>NO WARRANTY</strong>.</em>
15  * See <a href='http://www.saxproject.org'>http://www.saxproject.org</a>
16  * for further information.
17  * </blockquote>
18  *
19  * <p>If a SAX application needs to implement customized error
20  * handling, it must implement this interface and then register an
21  * instance with the XML reader using the
22  * {@link org.xml.sax.XMLReader#setErrorHandler setErrorHandler}
23  * method.  The parser will then report all errors and warnings
24  * through this interface.</p>
25  *
26  * <p><strong>WARNING:</strong> If an application does <em>not</em>
27  * register an ErrorHandler, XML parsing errors will go unreported,
28  * except that <em>SAXParseException</em>s will be thrown for fatal errors.
29  * In order to detect validity errors, an ErrorHandler that does something
30  * with {@link #error error()} calls must be registered.</p>
31  *
32  * <p>For XML processing errors, a SAX driver must use this interface
33  * in preference to throwing an exception: it is up to the application
34  * to decide whether to throw an exception for different types of
35  * errors and warnings.  Note, however, that there is no requirement that
36  * the parser continue to report additional errors after a call to
37  * {@link #fatalError fatalError}.  In other words, a SAX driver class
38  * may throw an exception after reporting any fatalError.
39  * Also parsers may throw appropriate exceptions for non-XML errors.
40  * For example, {@link XMLReader#parse XMLReader.parse()} would throw
41  * an IOException for errors accessing entities or the document.</p>
42  *
43  * @since SAX 1.0
44  * @author David Megginson
45  * @version 2.0.1+ (sax2r3pre1)
46  * @see org.xml.sax.XMLReader#setErrorHandler
47  * @see org.xml.sax.SAXParseException
48  */
49 public interface ErrorHandler {
50 
51 
52     /**
53      * Receive notification of a warning.
54      *
55      * <p>SAX parsers will use this method to report conditions that
56      * are not errors or fatal errors as defined by the XML
57      * recommendation.  The default behaviour is to take no
58      * action.</p>
59      *
60      * <p>The SAX parser must continue to provide normal parsing events
61      * after invoking this method: it should still be possible for the
62      * application to process the document through to the end.</p>
63      *
64      * <p>Filters may use this method to report other, non-XML warnings
65      * as well.</p>
66      *
67      * @param exception The warning information encapsulated in a
68      *                  SAX parse exception.
69      * @exception org.xml.sax.SAXException Any SAX exception, possibly
70      *            wrapping another exception.
71      * @see org.xml.sax.SAXParseException
72      */
warning(SAXParseException exception)73     public abstract void warning (SAXParseException exception)
74     throws SAXException;
75 
76 
77     /**
78      * Receive notification of a recoverable error.
79      *
80      * <p>This corresponds to the definition of "error" in section 1.2
81      * of the W3C XML 1.0 Recommendation.  For example, a validating
82      * parser would use this callback to report the violation of a
83      * validity constraint.  The default behaviour is to take no
84      * action.</p>
85      *
86      * <p>The SAX parser must continue to provide normal parsing
87      * events after invoking this method: it should still be possible
88      * for the application to process the document through to the end.
89      * If the application cannot do so, then the parser should report
90      * a fatal error even if the XML recommendation does not require
91      * it to do so.</p>
92      *
93      * <p>Filters may use this method to report other, non-XML errors
94      * as well.</p>
95      *
96      * @param exception The error information encapsulated in a
97      *                  SAX parse exception.
98      * @exception org.xml.sax.SAXException Any SAX exception, possibly
99      *            wrapping another exception.
100      * @see org.xml.sax.SAXParseException
101      */
error(SAXParseException exception)102     public abstract void error (SAXParseException exception)
103     throws SAXException;
104 
105 
106     /**
107      * Receive notification of a non-recoverable error.
108      *
109      * <p><strong>There is an apparent contradiction between the
110      * documentation for this method and the documentation for {@link
111      * org.xml.sax.ContentHandler#endDocument}.  Until this ambiguity
112      * is resolved in a future major release, clients should make no
113      * assumptions about whether endDocument() will or will not be
114      * invoked when the parser has reported a fatalError() or thrown
115      * an exception.</strong></p>
116      *
117      * <p>This corresponds to the definition of "fatal error" in
118      * section 1.2 of the W3C XML 1.0 Recommendation.  For example, a
119      * parser would use this callback to report the violation of a
120      * well-formedness constraint.</p>
121      *
122      * <p>The application must assume that the document is unusable
123      * after the parser has invoked this method, and should continue
124      * (if at all) only for the sake of collecting additional error
125      * messages: in fact, SAX parsers are free to stop reporting any
126      * other events once this method has been invoked.</p>
127      *
128      * @param exception The error information encapsulated in a
129      *                  SAX parse exception.
130      * @exception org.xml.sax.SAXException Any SAX exception, possibly
131      *            wrapping another exception.
132      * @see org.xml.sax.SAXParseException
133      */
fatalError(SAXParseException exception)134     public abstract void fatalError (SAXParseException exception)
135     throws SAXException;
136 
137 }
138 
139 // end of ErrorHandler.java
140