LexicalHandler


1   // LexicalHandler.java - optional handler for lexical parse events.
2   // http://www.saxproject.org
3   // Public Domain: no warranty.
4   // $Id: LexicalHandler.java,v 1.1.24.1 2004/05/01 08:34:43 jsuttor Exp $
5   
6   package org.xml.sax.ext;
7   
8   import org.xml.sax.SAXException  ;
9   
10  /**
11   * SAX2 extension handler for lexical events.
12   *
13   * <blockquote>
14   * <em>This module, both source code and documentation, is in the
15   * Public Domain, and comes with <strong>NO WARRANTY</strong>.</em>
16   * See <a HREF='http://www.saxproject.org'>http://www.saxproject.org</a>
17   * for further information.
18   * </blockquote>
19   *
20   * <p>This is an optional extension handler for SAX2 to provide
21   * lexical information about an XML document, such as comments
22   * and CDATA section boundaries.
23   * XML readers are not required to recognize this handler, and it
24   * is not part of core-only SAX2 distributions.</p>
25   *
26   * <p>The events in the lexical handler apply to the entire document,
27   * not just to the document element, and all lexical handler events
28   * must appear between the content handler's startDocument and
29   * endDocument events.</p>
30   *
31   * <p>To set the LexicalHandler for an XML reader, use the
32   * {@link org.xml.sax.XMLReader#setProperty setProperty} method
33   * with the property name
34   * <code>http://xml.org/sax/properties/lexical-handler</code>
35   * and an object implementing this interface (or null) as the value.
36   * If the reader does not report lexical events, it will throw a
37   * {@link org.xml.sax.SAXNotRecognizedException SAXNotRecognizedException}
38   * when you attempt to register the handler.</p>
39   *
40   * @since SAX 2.0 (extensions 1.0)
41   * @author David Megginson
42   * @version 2.0.1 (sax2r2)
43   */
44  public interface LexicalHandler
45  {
46  
47      /**
48       * Report the start of DTD declarations, if any.
49       *
50       * <p>This method is intended to report the beginning of the
51       * DOCTYPE declaration; if the document has no DOCTYPE declaration,
52       * this method will not be invoked.</p>
53       *
54       * <p>All declarations reported through 
55       * {@link org.xml.sax.DTDHandler DTDHandler} or
56       * {@link org.xml.sax.ext.DeclHandler DeclHandler} events must appear
57       * between the startDTD and {@link #endDTD endDTD} events.
58       * Declarations are assumed to belong to the internal DTD subset
59       * unless they appear between {@link #startEntity startEntity}
60       * and {@link #endEntity endEntity} events.  Comments and
61       * processing instructions from the DTD should also be reported
62       * between the startDTD and endDTD events, in their original 
63       * order of (logical) occurrence; they are not required to
64       * appear in their correct locations relative to DTDHandler
65       * or DeclHandler events, however.</p>
66       *
67       * <p>Note that the start/endDTD events will appear within
68       * the start/endDocument events from ContentHandler and
69       * before the first 
70       * {@link org.xml.sax.ContentHandler#startElement startElement}
71       * event.</p>
72       *
73       * @param name The document type name.
74       * @param publicId The declared public identifier for the
75       *        external DTD subset, or null if none was declared.
76       * @param systemId The declared system identifier for the
77       *        external DTD subset, or null if none was declared.
78       *        (Note that this is not resolved against the document
79       *        base URI.)
80       * @exception SAXException The application may raise an
81       *            exception.
82       * @see #endDTD
83       * @see #startEntity
84       */
85      public abstract void startDTD (String   name, String   publicId,
86                     String   systemId)
87      throws SAXException  ;
88  
89  
90      /**
91       * Report the end of DTD declarations.
92       *
93       * <p>This method is intended to report the end of the
94       * DOCTYPE declaration; if the document has no DOCTYPE declaration,
95       * this method will not be invoked.</p>
96       *
97       * @exception SAXException The application may raise an exception.
98       * @see #startDTD
99       */
100     public abstract void endDTD ()
101     throws SAXException  ;
102 
103 
104     /**
105      * Report the beginning of some internal and external XML entities.
106      *
107      * <p>The reporting of parameter entities (including
108      * the external DTD subset) is optional, and SAX2 drivers that
109      * report LexicalHandler events may not implement it; you can use the
110      * <code
111      * >http://xml.org/sax/features/lexical-handler/parameter-entities</code>
112      * feature to query or control the reporting of parameter entities.</p>
113      *
114      * <p>General entities are reported with their regular names,
115      * parameter entities have '%' prepended to their names, and 
116      * the external DTD subset has the pseudo-entity name "[dtd]".</p>
117      *
118      * <p>When a SAX2 driver is providing these events, all other 
119      * events must be properly nested within start/end entity 
120      * events.  There is no additional requirement that events from 
121      * {@link org.xml.sax.ext.DeclHandler DeclHandler} or
122      * {@link org.xml.sax.DTDHandler DTDHandler} be properly ordered.</p>
123      *
124      * <p>Note that skipped entities will be reported through the
125      * {@link org.xml.sax.ContentHandler#skippedEntity skippedEntity}
126      * event, which is part of the ContentHandler interface.</p>
127      *
128      * <p>Because of the streaming event model that SAX uses, some
129      * entity boundaries cannot be reported under any 
130      * circumstances:</p>
131      *
132      * <ul>
133      * <li>general entities within attribute values</li>
134      * <li>parameter entities within declarations</li>
135      * </ul>
136      *
137      * <p>These will be silently expanded, with no indication of where
138      * the original entity boundaries were.</p>
139      *
140      * <p>Note also that the boundaries of character references (which
141      * are not really entities anyway) are not reported.</p>
142      *
143      * <p>All start/endEntity events must be properly nested.
144      *
145      * @param name The name of the entity.  If it is a parameter
146      *        entity, the name will begin with '%', and if it is the
147      *        external DTD subset, it will be "[dtd]".
148      * @exception SAXException The application may raise an exception.
149      * @see #endEntity
150      * @see org.xml.sax.ext.DeclHandler#internalEntityDecl
151      * @see org.xml.sax.ext.DeclHandler#externalEntityDecl 
152      */
153     public abstract void startEntity (String   name)
154     throws SAXException  ;
155 
156 
157     /**
158      * Report the end of an entity.
159      *
160      * @param name The name of the entity that is ending.
161      * @exception SAXException The application may raise an exception.
162      * @see #startEntity
163      */
164     public abstract void endEntity (String   name)
165     throws SAXException  ;
166 
167 
168     /**
169      * Report the start of a CDATA section.
170      *
171      * <p>The contents of the CDATA section will be reported through
172      * the regular {@link org.xml.sax.ContentHandler#characters
173      * characters} event; this event is intended only to report
174      * the boundary.</p>
175      *
176      * @exception SAXException The application may raise an exception.
177      * @see #endCDATA
178      */
179     public abstract void startCDATA ()
180     throws SAXException  ;
181 
182 
183     /**
184      * Report the end of a CDATA section.
185      *
186      * @exception SAXException The application may raise an exception.
187      * @see #startCDATA
188      */
189     public abstract void endCDATA ()
190     throws SAXException  ;
191 
192 
193     /**
194      * Report an XML comment anywhere in the document.
195      *
196      * <p>This callback will be used for comments inside or outside the
197      * document element, including comments in the external DTD
198      * subset (if read).  Comments in the DTD must be properly
199      * nested inside start/endDTD and start/endEntity events (if
200      * used).</p>
201      *
202      * @param ch An array holding the characters in the comment.
203      * @param start The starting position in the array.
204      * @param length The number of characters to use from the array.
205      * @exception SAXException The application may raise an exception.
206      */
207     public abstract void comment (char ch[], int start, int length)
208     throws SAXException  ;
209 
210 }
211 
212 // end of LexicalHandler.java
213
A to Z: JavaDoc & Examples Daily Java News & Articles Open Source Projects Open Source Codes Free Computer Books Remove Frame
Popular Tags