001: /*
002: * This file is part of the WfMOpen project.
003: * Copyright (C) 2001-2003 Danet GmbH (www.danet.de), GS-AN.
004: * All rights reserved.
005: *
006: * This program is free software; you can redistribute it and/or modify
007: * it under the terms of the GNU General Public License as published by
008: * the Free Software Foundation; either version 2 of the License, or
009: * (at your option) any later version.
010: *
011: * This program is distributed in the hope that it will be useful,
012: * but WITHOUT ANY WARRANTY; without even the implied warranty of
013: * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
014: * GNU General Public License for more details.
015: *
016: * You should have received a copy of the GNU General Public License
017: * along with this program; if not, write to the Free Software
018: * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
019: *
020: * $Id: StackableDefaultHandler.java,v 1.2 2006/09/29 12:32:10 drmlipp Exp $
021: *
022: * $Log: StackableDefaultHandler.java,v $
023: * Revision 1.2 2006/09/29 12:32:10 drmlipp
024: * Consistently using WfMOpen as projct name now.
025: *
026: * Revision 1.1.1.1 2003/06/30 20:05:17 drmlipp
027: * Initial import
028: *
029: * Revision 1.4 2003/06/27 08:51:44 lipp
030: * Fixed copyright/license information.
031: *
032: * Revision 1.3 2001/10/12 14:17:05 montag
033: * Can now parse the test example.
034: *
035: *
036: */
037:
038: package de.danet.an.workflow.util;
039:
040: import java.io.*;
041:
042: import org.xml.sax.*;
043: import org.xml.sax.helpers.DefaultHandler;
044:
045: /**
046: * Base class for objects able to handle sax events.
047: * derived classes must override the startElement() and
048: * endElement() method.<p>
049: * To give back the control to the parent control
050: * handler, the derived content handler called the terminate()
051: * method if he receives the endElement()-Event for his ending
052: * tag.<p>
053: * Derived classes are normaly inner classes of the associated
054: * domain class (e.g. CustomerOrder or SchedulingScheme)
055: */
056: public class StackableDefaultHandler extends DefaultHandler {
057:
058: /**
059: * The content handler who called this handler.
060: */
061: protected ContentHandler parentContentHandler;
062:
063: /**
064: * The sax parser.
065: */
066: protected XMLReader parser;
067:
068: /**
069: * Buffer for collecting data from the "characters" SAX event.
070: */
071: protected CharArrayWriter contents = new CharArrayWriter();
072:
073: /**
074: * Default constructor.
075: * @param parser SAX parser
076: */
077: public StackableDefaultHandler(XMLReader parser) {
078: super ();
079: this .parser = parser;
080: // get current content handler
081: parentContentHandler = parser.getContentHandler();
082: // set the new content handler
083: parser.setContentHandler(this );
084: }
085:
086: /**
087: * Finish this handler and give control back to
088: * previous handler.
089: * Called if the handler receives the endElement()-Event
090: * for his ending tag.<p>
091: */
092: public void terminate() {
093: // set previous content handler
094: if (parentContentHandler != null) {
095: parser.setContentHandler(parentContentHandler);
096: }
097: }
098:
099: /**
100: * The Parser will call this method to report each chunk of character
101: * data. SAX parsers may return all contiguous character data in a
102: * single chunk, or they may split it into several chunks; however,
103: * all of the characters in any single event must come from the same
104: * external entity so that the Locator provides useful information.
105: * @param ch The characters from the XML document.
106: * @param start The start position in the array.
107: * @param length The number of characters to read from the array.
108: * @throws SAXException
109: */
110: public void characters(char[] ch, int start, int length)
111: throws SAXException {
112: contents.write(ch, start, length);
113: }
114:
115: }
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