franta-hg@11: /**
franta-hg@11:  * Alt2XML
franta-hg@11:  * Copyright © 2014 František Kučera (frantovo.cz)
franta-hg@11:  *
franta-hg@11:  * This program is free software: you can redistribute it and/or modify
franta-hg@11:  * it under the terms of the GNU General Public License as published by
franta-hg@111:  * the Free Software Foundation, version 3 of the License.
franta-hg@11:  *
franta-hg@11:  * This program is distributed in the hope that it will be useful,
franta-hg@11:  * but WITHOUT ANY WARRANTY; without even the implied warranty of
franta-hg@11:  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
franta-hg@11:  * GNU General Public License for more details.
franta-hg@11:  *
franta-hg@11:  * You should have received a copy of the GNU General Public License
franta-hg@11:  * along with this program. If not, see <http://www.gnu.org/licenses/>.
franta-hg@11:  */
franta-hg@2: package cz.frantovo.alt2xml;
franta-hg@2: 
franta-hg@15: import java.util.Deque;
franta-hg@99: import java.util.HashMap;
franta-hg@15: import java.util.LinkedList;
franta-hg@99: import java.util.Map;
franta-hg@99: import java.util.Map.Entry;
franta-hg@15: import java.util.ServiceLoader;
franta-hg@34: import javax.xml.parsers.FactoryConfigurationError;
franta-hg@2: import javax.xml.parsers.ParserConfigurationException;
franta-hg@2: import javax.xml.parsers.SAXParser;
franta-hg@2: import javax.xml.parsers.SAXParserFactory;
franta-hg@2: import org.xml.sax.SAXException;
franta-hg@2: import org.xml.sax.SAXNotRecognizedException;
franta-hg@2: import org.xml.sax.SAXNotSupportedException;
franta-hg@3: import org.xml.sax.XMLReader;
franta-hg@2: 
franta-hg@2: /**
franta-hg@2:  *
franta-hg@19:  * @author Ing. František Kučera (frantovo.cz)
franta-hg@2:  */
franta-hg@16: public class ParserFactory extends SAXParserFactory implements ReaderFinder {
franta-hg@15: 
franta-hg@15: 	private final Deque<Alt2XmlReaderFactory> readerFactories = new LinkedList();
franta-hg@34: 	/**
franta-hg@34: 	 * @see #DEFAULT_FACTORY_PROPERTY
franta-hg@34: 	 */
franta-hg@34: 	private SAXParserFactory fallbackFactory;
franta-hg@34: 
franta-hg@34: 	/**
franta-hg@34: 	 * System property which contains SAXParserFactory class name for XML.
franta-hg@34: 	 * Will be used as fallback if no alternative factory matches systemId to be parsed.
franta-hg@34: 	 */
franta-hg@34: 	public static final String DEFAULT_FACTORY_PROPERTY = "cz.frantovo.alt2xml.fallback.javax.xml.parsers.SAXParserFactory";
franta-hg@15: 
franta-hg@99: 	private final Map<String, Boolean> features = new HashMap<>();
franta-hg@99: 
franta-hg@16: 	public ParserFactory() {
franta-hg@15: 		super();
franta-hg@15: 		for (Alt2XmlReaderFactory f : ServiceLoader.load(Alt2XmlReaderFactory.class)) {
franta-hg@15: 			readerFactories.add(f);
franta-hg@15: 		}
franta-hg@15: 
franta-hg@34: 		readerFactories.add(new FallbackReaderFactory());
franta-hg@34: 	}
franta-hg@34: 
franta-hg@34: 	/**
franta-hg@34: 	 * @return factory to be used for XML documents (default/fallback)
franta-hg@34: 	 * @throws FactoryConfigurationError if fallback factory is the same one as this – avoid
franta-hg@34: 	 * infinite recursion.
franta-hg@34: 	 */
franta-hg@34: 	public SAXParserFactory getFallbackFactory() {
franta-hg@34: 		if (fallbackFactory == null) {
franta-hg@34: 			String className = System.getProperty(DEFAULT_FACTORY_PROPERTY);
franta-hg@34: 			if (className == null) {
franta-hg@34: 				fallbackFactory = SAXParserFactory.newInstance();
franta-hg@34: 			} else {
franta-hg@34: 				fallbackFactory = SAXParserFactory.newInstance(className, null);
franta-hg@34: 			}
franta-hg@34: 		}
franta-hg@34: 
franta-hg@34: 		if (fallbackFactory.getClass().equals(getClass())) {
franta-hg@34: 			throw new FactoryConfigurationError("Fallback factory is the same class as this one – avoid infinite recursion: " + getClass());
franta-hg@34: 		} else {
franta-hg@34: 			return fallbackFactory;
franta-hg@34: 		}
franta-hg@34: 	}
franta-hg@34: 
franta-hg@34: 	public void setFallbackFactory(SAXParserFactory fallbackFactory) {
franta-hg@34: 		this.fallbackFactory = fallbackFactory;
franta-hg@34: 	}
franta-hg@34: 
franta-hg@34: 	private class FallbackReaderFactory implements Alt2XmlReaderFactory {
franta-hg@34: 
franta-hg@34: 		@Override
franta-hg@36: 		public boolean canRead(AltInputSource inputSource) {
franta-hg@34: 			return true;
franta-hg@34: 		}
franta-hg@34: 
franta-hg@34: 		@Override
franta-hg@34: 		public XMLReader getReader() throws SAXException {
franta-hg@34: 
franta-hg@34: 			try {
franta-hg@34: 				return getFallbackFactory().newSAXParser().getXMLReader();
franta-hg@34: 			} catch (ParserConfigurationException e) {
franta-hg@34: 				throw new SAXException("Unable to instantiate the fallback factory.", e);
franta-hg@34: 			}
franta-hg@34: 		}
franta-hg@15: 	}
franta-hg@15: 
franta-hg@15: 	@Override
franta-hg@36: 	public XMLReader findReader(AltInputSource inputSource) throws SAXException {
franta-hg@15: 		for (Alt2XmlReaderFactory f : readerFactories) {
franta-hg@36: 			if (f.canRead(inputSource)) {
franta-hg@15: 				return f.getReader();
franta-hg@15: 			}
franta-hg@15: 		}
franta-hg@36: 		throw new SAXException("Iterated over " + readerFactories.size() + " and was unable to find XMLReader for SystemId: " + inputSource);
franta-hg@15: 	}
franta-hg@2: 
franta-hg@2: 	@Override
franta-hg@2: 	public SAXParser newSAXParser() throws ParserConfigurationException, SAXException {
franta-hg@99: 		SuperReader r = new SuperReader(this);
franta-hg@99: 		for (Entry<String, Boolean> f : features.entrySet()) {
franta-hg@99: 			r.setFeature(f.getKey(), f.getValue());
franta-hg@99: 		}
franta-hg@99: 		return new AltSAXParser(r);
franta-hg@2: 	}
franta-hg@2: 
franta-hg@2: 	@Override
franta-hg@2: 	public void setFeature(String name, boolean value) throws ParserConfigurationException, SAXNotRecognizedException, SAXNotSupportedException {
franta-hg@99: 		features.put(name, value);
franta-hg@2: 	}
franta-hg@2: 
franta-hg@2: 	@Override
franta-hg@2: 	public boolean getFeature(String name) throws ParserConfigurationException, SAXNotRecognizedException, SAXNotSupportedException {
franta-hg@99: 		return features.get(name);
franta-hg@2: 	}
franta-hg@15: }