001: /* ========================================================================
002: * JCommon : a free general purpose class library for the Java(tm) platform
003: * ========================================================================
004: *
005: * (C) Copyright 2000-2005, by Object Refinery Limited and Contributors.
006: *
007: * Project Info: http://www.jfree.org/jcommon/index.html
008: *
009: * This library is free software; you can redistribute it and/or modify it
010: * under the terms of the GNU Lesser General Public License as published by
011: * the Free Software Foundation; either version 2.1 of the License, or
012: * (at your option) any later version.
013: *
014: * This library is distributed in the hope that it will be useful, but
015: * WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
016: * or FITNESS FOR A PARTICULAR PURPOSE. See the GNU Lesser General Public
017: * License for more details.
018: *
019: * You should have received a copy of the GNU Lesser General Public
020: * License along with this library; if not, write to the Free Software
021: * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301,
022: * USA.
023: *
024: * [Java is a trademark or registered trademark of Sun Microsystems, Inc.
025: * in the United States and other countries.]
026: *
027: * -------------------
028: * CommentHandler.java
029: * -------------------
030: * (C)opyright 2003-2005, by Thomas Morgner and Contributors.
031: *
032: * Original Author: Thomas Morgner;
033: * Contributor(s): David Gilbert (for Object Refinery Limited);
034: *
035: * $Id: CommentHandler.java,v 1.3 2005/10/18 13:25:44 mungady Exp $
036: *
037: * Changes
038: * -------------------------
039: * 20-Jul-2003 : Initial version
040: *
041: */
042:
043: package org.jfree.xml;
044:
045: import java.util.ArrayList;
046:
047: import org.xml.sax.SAXException;
048: import org.xml.sax.ext.LexicalHandler;
049:
050: /**
051: * The comment handler is used to collect all XML comments from the
052: * SAX parser. The parser implementation must support comments to make
053: * this feature work.
054: *
055: * @author Thomas Morgner
056: */
057: public class CommentHandler implements LexicalHandler {
058:
059: /** A constant marking a comment on the opening tag. */
060: public static final String OPEN_TAG_COMMENT = "parser.comment.open";
061:
062: /** A constant marking a comment on the closing tag. */
063: public static final String CLOSE_TAG_COMMENT = "parser.comment.close";
064:
065: /** A list containing all collected comments. */
066: private final ArrayList comment;
067:
068: /** a flag marking whether the SAX parser is currently working in the DTD. */
069: private boolean inDTD;
070:
071: /**
072: * DefaultConstructor.
073: */
074: public CommentHandler() {
075: this .comment = new ArrayList();
076: }
077:
078: /**
079: * Report the start of DTD declarations, if any.
080: *
081: * <p>This method is empty.</p>
082: *
083: * @param name The document type name.
084: * @param publicId The declared public identifier for the
085: * external DTD subset, or null if none was declared.
086: * @param systemId The declared system identifier for the
087: * external DTD subset, or null if none was declared.
088: * @exception org.xml.sax.SAXException The application may raise an
089: * exception.
090: * @see #endDTD()
091: * @see #startEntity(String)
092: */
093: public void startDTD(final String name, final String publicId,
094: final String systemId) throws SAXException {
095: this .inDTD = true;
096: }
097:
098: /**
099: * Report the end of DTD declarations.
100: *
101: * <p>This method is empty.</p>
102: *
103: * @exception org.xml.sax.SAXException The application may raise an exception.
104: */
105: public void endDTD() throws SAXException {
106: this .inDTD = false;
107: }
108:
109: /**
110: * Report the beginning of some internal and external XML entities.
111: *
112: * <p>This method is empty.</p>
113: *
114: * @param name The name of the entity. If it is a parameter
115: * entity, the name will begin with '%', and if it is the
116: * external DTD subset, it will be "[dtd]".
117: * @exception org.xml.sax.SAXException The application may raise an exception.
118: * @see #endEntity(String)
119: * @see org.xml.sax.ext.DeclHandler#internalEntityDecl
120: * @see org.xml.sax.ext.DeclHandler#externalEntityDecl
121: */
122: public void startEntity(final String name) throws SAXException {
123: // do nothing
124: }
125:
126: /**
127: * Report the end of an entity.
128: *
129: * <p>This method is empty.</p>
130: *
131: * @param name The name of the entity that is ending.
132: * @exception org.xml.sax.SAXException The application may raise an exception.
133: * @see #startEntity(String)
134: */
135: public void endEntity(final String name) throws SAXException {
136: // do nothing
137: }
138:
139: /**
140: * Report the start of a CDATA section.
141: *
142: * <p>This method is empty.</p>
143: *
144: * @exception org.xml.sax.SAXException The application may raise an exception.
145: * @see #endCDATA()
146: */
147: public void startCDATA() throws SAXException {
148: // do nothing
149: }
150:
151: /**
152: * Report the end of a CDATA section.
153: *
154: * <p>This method is empty.</p>
155: *
156: * @exception org.xml.sax.SAXException The application may raise an exception.
157: * @see #startCDATA()
158: */
159: public void endCDATA() throws SAXException {
160: // do nothing
161: }
162:
163: /**
164: * Report an XML comment anywhere in the document.
165: *
166: * <p>This callback will be used for comments inside or outside the
167: * document element, including comments in the external DTD
168: * subset (if read). Comments in the DTD must be properly
169: * nested inside start/endDTD and start/endEntity events (if
170: * used).</p>
171: *
172: * @param ch An array holding the characters in the comment.
173: * @param start The starting position in the array.
174: * @param length The number of characters to use from the array.
175: * @exception org.xml.sax.SAXException The application may raise an exception.
176: */
177: public void comment(final char[] ch, final int start,
178: final int length) throws SAXException {
179: if (!this .inDTD) {
180: this .comment.add(new String(ch, start, length));
181: }
182: }
183:
184: /**
185: * Returns all collected comments as string array.
186: * @return the array containing all comments.
187: */
188: public String[] getComments() {
189: if (this .comment.isEmpty()) {
190: return null;
191: }
192: return (String[]) this .comment.toArray(new String[this .comment
193: .size()]);
194: }
195:
196: /**
197: * Clears all comments.
198: */
199: public void clearComments() {
200: this.comment.clear();
201: }
202: }
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