View Javadoc
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  // LexicalHandler.java - optional handler for lexical parse events.
27  // http://www.saxproject.org
28  // Public Domain: no warranty.
29  // $Id: LexicalHandler.java,v 1.2 2004/11/03 22:49:08 jsuttor Exp $
30  
31  package org.xml.sax.ext;
32  
33  import org.xml.sax.SAXException;
34  
35  /**
36   * SAX2 extension handler for lexical events.
37   *
38   * <blockquote>
39   * <em>This module, both source code and documentation, is in the
40   * Public Domain, and comes with <strong>NO WARRANTY</strong>.</em>
41   * See <a href='http://www.saxproject.org'>http://www.saxproject.org</a>;
42   * for further information.
43   * </blockquote>
44   *
45   * <p>This is an optional extension handler for SAX2 to provide
46   * lexical information about an XML document, such as comments
47   * and CDATA section boundaries.
48   * XML readers are not required to recognize this handler, and it
49   * is not part of core-only SAX2 distributions.</p>
50   *
51   * <p>The events in the lexical handler apply to the entire document,
52   * not just to the document element, and all lexical handler events
53   * must appear between the content handler's startDocument and
54   * endDocument events.</p>
55   *
56   * <p>To set the LexicalHandler for an XML reader, use the
57   * {@link org.xml.sax.XMLReader#setProperty setProperty} method
58   * with the property name
59   * <code>http://xml.org/sax/properties/lexical-handler</code>;
60   * and an object implementing this interface (or null) as the value.
61   * If the reader does not report lexical events, it will throw a
62   * {@link org.xml.sax.SAXNotRecognizedException SAXNotRecognizedException}
63   * when you attempt to register the handler.</p>
64   *
65   * @since SAX 2.0 (extensions 1.0)
66   * @author David Megginson
67   */
68  public interface LexicalHandler
69  {
70  
71      /**
72       * Report the start of DTD declarations, if any.
73       *
74       * <p>This method is intended to report the beginning of the
75       * DOCTYPE declaration; if the document has no DOCTYPE declaration,
76       * this method will not be invoked.</p>
77       *
78       * <p>All declarations reported through
79       * {@link org.xml.sax.DTDHandler DTDHandler} or
80       * {@link org.xml.sax.ext.DeclHandler DeclHandler} events must appear
81       * between the startDTD and {@link #endDTD endDTD} events.
82       * Declarations are assumed to belong to the internal DTD subset
83       * unless they appear between {@link #startEntity startEntity}
84       * and {@link #endEntity endEntity} events.  Comments and
85       * processing instructions from the DTD should also be reported
86       * between the startDTD and endDTD events, in their original
87       * order of (logical) occurrence; they are not required to
88       * appear in their correct locations relative to DTDHandler
89       * or DeclHandler events, however.</p>
90       *
91       * <p>Note that the start/endDTD events will appear within
92       * the start/endDocument events from ContentHandler and
93       * before the first
94       * {@link org.xml.sax.ContentHandler#startElement startElement}
95       * event.</p>
96       *
97       * @param name The document type name.
98       * @param publicId The declared public identifier for the
99       *        external DTD subset, or null if none was declared.
100      * @param systemId The declared system identifier for the
101      *        external DTD subset, or null if none was declared.
102      *        (Note that this is not resolved against the document
103      *        base URI.)
104      * @exception SAXException The application may raise an
105      *            exception.
106      * @see #endDTD
107      * @see #startEntity
108      */
109     public abstract void startDTD (String name, String publicId,
110                                    String systemId)
111         throws SAXException;
112 
113 
114     /**
115      * Report the end of DTD declarations.
116      *
117      * <p>This method is intended to report the end of the
118      * DOCTYPE declaration; if the document has no DOCTYPE declaration,
119      * this method will not be invoked.</p>
120      *
121      * @exception SAXException The application may raise an exception.
122      * @see #startDTD
123      */
124     public abstract void endDTD ()
125         throws SAXException;
126 
127 
128     /**
129      * Report the beginning of some internal and external XML entities.
130      *
131      * <p>The reporting of parameter entities (including
132      * the external DTD subset) is optional, and SAX2 drivers that
133      * report LexicalHandler events may not implement it; you can use the
134      * <code
135      * >http://xml.org/sax/features/lexical-handler/parameter-entities</code>;
136      * feature to query or control the reporting of parameter entities.</p>
137      *
138      * <p>General entities are reported with their regular names,
139      * parameter entities have '%' prepended to their names, and
140      * the external DTD subset has the pseudo-entity name "[dtd]".</p>
141      *
142      * <p>When a SAX2 driver is providing these events, all other
143      * events must be properly nested within start/end entity
144      * events.  There is no additional requirement that events from
145      * {@link org.xml.sax.ext.DeclHandler DeclHandler} or
146      * {@link org.xml.sax.DTDHandler DTDHandler} be properly ordered.</p>
147      *
148      * <p>Note that skipped entities will be reported through the
149      * {@link org.xml.sax.ContentHandler#skippedEntity skippedEntity}
150      * event, which is part of the ContentHandler interface.</p>
151      *
152      * <p>Because of the streaming event model that SAX uses, some
153      * entity boundaries cannot be reported under any
154      * circumstances:</p>
155      *
156      * <ul>
157      * <li>general entities within attribute values</li>
158      * <li>parameter entities within declarations</li>
159      * </ul>
160      *
161      * <p>These will be silently expanded, with no indication of where
162      * the original entity boundaries were.</p>
163      *
164      * <p>Note also that the boundaries of character references (which
165      * are not really entities anyway) are not reported.</p>
166      *
167      * <p>All start/endEntity events must be properly nested.
168      *
169      * @param name The name of the entity.  If it is a parameter
170      *        entity, the name will begin with '%', and if it is the
171      *        external DTD subset, it will be "[dtd]".
172      * @exception SAXException The application may raise an exception.
173      * @see #endEntity
174      * @see org.xml.sax.ext.DeclHandler#internalEntityDecl
175      * @see org.xml.sax.ext.DeclHandler#externalEntityDecl
176      */
177     public abstract void startEntity (String name)
178         throws SAXException;
179 
180 
181     /**
182      * Report the end of an entity.
183      *
184      * @param name The name of the entity that is ending.
185      * @exception SAXException The application may raise an exception.
186      * @see #startEntity
187      */
188     public abstract void endEntity (String name)
189         throws SAXException;
190 
191 
192     /**
193      * Report the start of a CDATA section.
194      *
195      * <p>The contents of the CDATA section will be reported through
196      * the regular {@link org.xml.sax.ContentHandler#characters
197      * characters} event; this event is intended only to report
198      * the boundary.</p>
199      *
200      * @exception SAXException The application may raise an exception.
201      * @see #endCDATA
202      */
203     public abstract void startCDATA ()
204         throws SAXException;
205 
206 
207     /**
208      * Report the end of a CDATA section.
209      *
210      * @exception SAXException The application may raise an exception.
211      * @see #startCDATA
212      */
213     public abstract void endCDATA ()
214         throws SAXException;
215 
216 
217     /**
218      * Report an XML comment anywhere in the document.
219      *
220      * <p>This callback will be used for comments inside or outside the
221      * document element, including comments in the external DTD
222      * subset (if read).  Comments in the DTD must be properly
223      * nested inside start/endDTD and start/endEntity events (if
224      * used).</p>
225      *
226      * @param ch An array holding the characters in the comment.
227      * @param start The starting position in the array.
228      * @param length The number of characters to use from the array.
229      * @exception SAXException The application may raise an exception.
230      */
231     public abstract void comment (char ch[], int start, int length)
232         throws SAXException;
233 
234 }
235 
236 // end of LexicalHandler.java