org.daisy.dotify.common.xml.CachingURIResolver Maven / Gradle / Ivy
/*
* org.daisy.util (C) 2005-2008 Daisy Consortium
*
* This library is free software; you can redistribute it and/or modify it under
* the terms of the GNU Lesser General Public License as published by the Free
* Software Foundation; either version 2.1 of the License, or (at your option)
* any later version.
*
* This library is distributed in the hope that it will be useful, but WITHOUT
* ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS
* FOR A PARTICULAR PURPOSE. See the GNU Lesser General Public License for more
* details.
*
* You should have received a copy of the GNU Lesser General Public License
* along with this library; if not, write to the Free Software Foundation, Inc.,
* 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
*/
package org.daisy.dotify.common.xml;
import org.xml.sax.InputSource;
import org.xml.sax.SAXException;
import org.xml.sax.XMLReader;
import java.io.File;
import java.io.FileInputStream;
import java.io.FileNotFoundException;
import java.net.URI;
import java.net.URISyntaxException;
import javax.xml.parsers.ParserConfigurationException;
import javax.xml.parsers.SAXParser;
import javax.xml.parsers.SAXParserFactory;
import javax.xml.transform.Source;
import javax.xml.transform.TransformerException;
import javax.xml.transform.URIResolver;
import javax.xml.transform.sax.SAXSource;
/**
* @author Linus Ericson
*/
public class CachingURIResolver implements URIResolver {
private final XMLReader reader;
/**
* Creates a new uri resolver.
*
* @throws XMLToolsException if something goes wrong
*/
public CachingURIResolver() throws XMLToolsException {
this(SAXParserFactory.newInstance());
}
/**
* Creates a new uri resolver with the specified sax parser factory.
*
* @param parserFactory the parser factory
* @throws XMLToolsException if something goes wrong
*/
public CachingURIResolver(SAXParserFactory parserFactory) throws XMLToolsException {
parserFactory.setNamespaceAware(true);
SAXParser parser;
try {
parser = parserFactory.newSAXParser();
reader = parser.getXMLReader();
} catch (ParserConfigurationException e) {
throw new XMLToolsException(e);
} catch (SAXException e) {
throw new XMLToolsException(e);
}
reader.setEntityResolver(new EntityResolverCache());
}
@Override
public Source resolve(String href, String base) throws TransformerException {
// Self reference, let the internal URIResolver handle it.
if (href == null || "".equals(href)) {
return null;
}
try {
URI hrefUri = new URI(href);
URI baseUri = new URI(base);
URI resolved = URIUtils.resolve(baseUri, hrefUri);
if ("file".equals(resolved.getScheme())) {
Source xmlSource = new SAXSource(reader, new InputSource(new FileInputStream(new File(resolved))));
return xmlSource;
}
} catch (URISyntaxException e) {
throw new TransformerException(e);
} catch (FileNotFoundException e) {
throw new TransformerException(e);
}
return null;
}
}