/* $Id: SAXParserBase.java 17832 2010-01-12 19:02:29Z linus $
*****************************************************************************
* Copyright (c) 2009 Contributors - see below
* All rights reserved. This program and the accompanying materials
* are made available under the terms of the Eclipse Public License v1.0
* which accompanies this distribution, and is available at
* http://www.eclipse.org/legal/epl-v10.html
*
* Contributors:
* tfmorris
*****************************************************************************
*
* Some portions of this file was previously release using the BSD License:
*/
// Copyright (c) 1996-2006 The Regents of the University of California. All
// Rights Reserved. Permission to use, copy, modify, and distribute this
// software and its documentation without fee, and without a written
// agreement is hereby granted, provided that the above copyright notice
// and this paragraph appear in all copies. This software program and
// documentation are copyrighted by The Regents of the University of
// California. The software program and documentation are supplied "AS
// IS", without any accompanying services from The Regents. The Regents
// does not warrant that the operation of the program will be
// uninterrupted or error-free. The end-user understands that the program
// was developed for research purposes and is advised not to rely
// exclusively on the program for any reason. IN NO EVENT SHALL THE
// UNIVERSITY OF CALIFORNIA BE LIABLE TO ANY PARTY FOR DIRECT, INDIRECT,
// SPECIAL, INCIDENTAL, OR CONSEQUENTIAL DAMAGES, INCLUDING LOST PROFITS,
// ARISING OUT OF THE USE OF THIS SOFTWARE AND ITS DOCUMENTATION, EVEN IF
// THE UNIVERSITY OF CALIFORNIA HAS BEEN ADVISED OF THE POSSIBILITY OF
// SUCH DAMAGE. THE UNIVERSITY OF CALIFORNIA SPECIFICALLY DISCLAIMS ANY
// WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
// MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE. THE SOFTWARE
// PROVIDED HEREUNDER IS ON AN "AS IS" BASIS, AND THE UNIVERSITY OF
// CALIFORNIA HAS NO OBLIGATIONS TO PROVIDE MAINTENANCE, SUPPORT,
// UPDATES, ENHANCEMENTS, OR MODIFICATIONS.
package org.argouml.persistence;
import java.io.FileInputStream;
import java.io.IOException;
import java.io.InputStream;
import java.io.Reader;
import java.net.URL;
import javax.xml.parsers.ParserConfigurationException;
import javax.xml.parsers.SAXParser;
import javax.xml.parsers.SAXParserFactory;
import org.apache.log4j.Logger;
import org.xml.sax.Attributes;
import org.xml.sax.InputSource;
import org.xml.sax.SAXException;
import org.xml.sax.helpers.DefaultHandler;
/**
* @author Jim Holt
*/
abstract class SAXParserBase extends DefaultHandler {
/**
* Logger.
*/
private static final Logger LOG = Logger.getLogger(SAXParserBase.class);
/**
* The constructor.
*/
public SAXParserBase() {
// empty constructor
}
////////////////////////////////////////////////////////////////
// static variables
/**
* Switching this to true gives some extra logging messages.
*/
protected static final boolean DBG = false;
/**
* This acts as a stack of elements.<p>
*
* {@link #startElement(String, String, String, Attributes)} places
* an item on the stack end {@link #endElement(String, String, String)}
* removes it.
*/
private static XMLElement[] elements = new XMLElement[100];
/**
* The number of items actually in use on the elements stack.
*/
private static int nElements = 0;
/**
* This acts as a stack of elements.<p>
*
* {@link #startElement(String, String, String, Attributes)} places
* an item on the stack end {@link #endElement(String, String, String)}
* removes it.
*/
private static XMLElement[] freeElements = new XMLElement[100];
private static int nFreeElements = 0;
private static boolean stats = true;
private static long parseTime = 0;
////////////////////////////////////////////////////////////////
// accessors
/**
* @param s true if statistics have to be shown
*/
public void setStats(boolean s) { stats = s; }
/**
* @return true if statistics have to be shown
*/
public boolean getStats() { return stats; }
/**
* @return the parsing time
*/
public long getParseTime() {
return parseTime;
}
/**
* @param reader the reader to read
* @throws SAXException when parsing xml
*/
public void parse(Reader reader) throws SAXException {
parse(new InputSource(reader));
}
/**
* @param input the InputSource to read
* @throws SAXException when parsing xml
*/
public void parse(InputSource input) throws SAXException {
long start, end;
SAXParserFactory factory = SAXParserFactory.newInstance();
factory.setNamespaceAware(false);
factory.setValidating(false);
try {
SAXParser parser = factory.newSAXParser();
// If we weren't given a system ID, attempt to use the URL for the
// JAR that we were loaded from. (Why? - tfm)
if (input.getSystemId() == null) {
input.setSystemId(getJarResource("org.argouml.kernel.Project"));
}
start = System.currentTimeMillis();
parser.parse(input, this);
end = System.currentTimeMillis();
parseTime = end - start;
} catch (IOException e) {
throw new SAXException(e);
} catch (ParserConfigurationException e) {
throw new SAXException(e);
}
if (stats && LOG.isInfoEnabled()) {
LOG.info("Elapsed time: " + (end - start) + " ms");
}
}
////////////////////////////////////////////////////////////////
// abstract methods
/**
* Implement in the concrete class to handle reaching the start tag of
* an element of interest.
* @param e the element.
* @throws SAXException on any error parsing the element.
*/
protected abstract void handleStartElement(XMLElement e)
throws SAXException;
/**
* Implement in the concrete class to handle reaching the end tag of
* an element of interest.
* @param e the element.
* @throws SAXException on any error parsing the element.
*/
protected abstract void handleEndElement(XMLElement e)
throws SAXException;
////////////////////////////////////////////////////////////////
// non-abstract methods
/*
* @see org.xml.sax.ContentHandler#startElement(java.lang.String,
* java.lang.String, java.lang.String, org.xml.sax.Attributes)
*/
public void startElement(String uri,
String localname,
String name,
Attributes atts) throws SAXException {
if (isElementOfInterest(name)) {
XMLElement element = createXmlElement(name, atts);
if (LOG.isDebugEnabled()) {
StringBuffer buf = new StringBuffer();
buf.append("START: ").append(name).append(' ').append(element);
for (int i = 0; i < atts.getLength(); i++) {
buf.append(" ATT: ")
.append(atts.getLocalName(i))
.append(' ')
.append(atts.getValue(i));
}
LOG.debug(buf.toString());
}
elements[nElements++] = element;
handleStartElement(element);
}
}
/**
* Factory method to return an XMLElement.
* This will reuse previously created elements when possible.
* @param name The element name.
* @param atts The element attributes.
* @return the element.
*/
private XMLElement createXmlElement(String name, Attributes atts) {
if (nFreeElements == 0) {
return new XMLElement(name, atts);
}
XMLElement e = freeElements[--nFreeElements];
e.setName(name);
e.setAttributes(atts);
e.resetText();
return e;
}
/*
* @see org.xml.sax.ContentHandler#endElement(java.lang.String,
* java.lang.String, java.lang.String)
*/
public void endElement(String uri, String localname, String name)
throws SAXException {
if (isElementOfInterest(name)) {
XMLElement e = elements[--nElements];
if (LOG.isDebugEnabled()) {
StringBuffer buf = new StringBuffer();
buf.append("END: " + e.getName() + " ["
+ e.getText() + "] " + e + "\n");
for (int i = 0; i < e.getNumAttributes(); i++) {
buf.append(" ATT: " + e.getAttributeName(i) + " "
+ e.getAttributeValue(i) + "\n");
}
LOG.debug(buf);
}
handleEndElement(e);
}
}
/**
* Determine if an element of the given name is of interest to
* the parser. The base implementation assumes always true.
*
* @param name the element name.
* @return true if the element name is of interest.
*/
protected boolean isElementOfInterest(String name) {
return true;
}
// TODO: remove when code below in characters() is removed
// private static final String RETURNSTRING = "\n ";
/*
* @see org.xml.sax.ContentHandler#characters(char[], int, int)
*/
public void characters(char[] ch, int start, int length)
throws SAXException {
elements[nElements - 1].addText(ch, start, length);
// TODO: Remove this old implementation after 0.22 if it's
// demonstrated that it's not needed. - tfm
// Why does the text get added to ALL the elements on the stack? - tfm
// for (int i = 0; i < nElements; i++) {
// XMLElement e = elements[i];
// if (e.length() > 0) {
// // This seems wrong since this method can be called
// // multiple times at the parser's discretion - tfm
// e.addText(RETURNSTRING);
// }
// e.addText(ch, start, length);
// }
}
/*
* @see org.xml.sax.EntityResolver#resolveEntity(java.lang.String,
* java.lang.String)
*/
public InputSource resolveEntity (String publicId, String systemId)
throws SAXException {
try {
URL testIt = new URL(systemId);
InputSource s = new InputSource(testIt.openStream());
return s;
} catch (Exception e) {
LOG.info("NOTE: Could not open DTD " + systemId
+ " due to exception");
String dtdName = systemId.substring(systemId.lastIndexOf('/') + 1);
String dtdPath = "/org/argouml/persistence/" + dtdName;
InputStream is = SAXParserBase.class.getResourceAsStream(dtdPath);
if (is == null) {
try {
is = new FileInputStream(dtdPath.substring(1));
} catch (Exception ex) {
throw new SAXException(e);
}
}
return new InputSource(is);
}
}
/**
* @param cls the class
* @return the jar
*/
public String getJarResource(String cls) {
//e.g:org.argouml.uml.generator.ui.ClassGenerationDialog -> poseidon.jar
String jarFile = "";
String fileSep = System.getProperty("file.separator");
String classFile = cls.replace('.', fileSep.charAt(0)) + ".class";
ClassLoader thisClassLoader = this.getClass().getClassLoader();
URL url = thisClassLoader.getResource(classFile);
if (url != null) {
String urlString = url.getFile();
int idBegin = urlString.indexOf("file:");
int idEnd = urlString.indexOf("!");
if (idBegin > -1 && idEnd > -1 && idEnd > idBegin) {
jarFile = urlString.substring(idBegin + 5, idEnd);
}
}
return jarFile;
}
////////////////////////////////////////////////////////////////
// convenience methods
/**
* @param e the element
*/
public void ignoreElement(XMLElement e) {
if (LOG.isDebugEnabled()) {
LOG.debug("NOTE: ignoring tag:" + e.getName());
}
}
/**
* @param e the element
*/
public void notImplemented(XMLElement e) {
if (LOG.isDebugEnabled()) {
LOG.debug("NOTE: element not implemented: " + e.getName());
}
}
} /* end class SAXParserBase */