/*
* Licensed to the Apache Software Foundation (ASF) under one or more
* contributor license agreements. See the NOTICE file distributed with
* this work for additional information regarding copyright ownership.
* The ASF licenses this file to You under the Apache License, Version 2.0
* (the "License"); you may not use this file except in compliance with
* the License. You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package org.apache.cocoon.sax.util;
import java.io.BufferedInputStream;
import java.io.ByteArrayInputStream;
import java.io.IOException;
import java.io.InputStream;
import java.io.OutputStream;
import java.io.StringReader;
import java.net.URLConnection;
import java.util.Properties;
import javax.xml.transform.TransformerFactory;
import javax.xml.transform.sax.SAXTransformerFactory;
import javax.xml.transform.sax.TransformerHandler;
import javax.xml.transform.stream.StreamResult;
import org.apache.cocoon.pipeline.PipelineException;
import org.apache.cocoon.pipeline.ProcessingException;
import org.apache.cocoon.pipeline.util.URLConnectionUtils;
import org.apache.cocoon.sax.SAXConsumer;
import org.apache.cocoon.xml.sax.EmbeddedSAXPipe;
import org.apache.cocoon.xml.sax.SAXBuffer;
import org.xml.sax.ContentHandler;
import org.xml.sax.EntityResolver;
import org.xml.sax.InputSource;
import org.xml.sax.SAXException;
import org.xml.sax.XMLReader;
import org.xml.sax.ext.LexicalHandler;
import org.xml.sax.helpers.XMLReaderFactory;
/**
* Utilities for the usage of an {@link XMLReader} together with a {@link SAXConsumer}.
*/
public abstract class XMLUtils {
private static final SAXTransformerFactory SAX_TRANSFORMER_FACTORY = (SAXTransformerFactory) TransformerFactory
.newInstance();
/**
* Serialize the content of a {@link SAXBuffer} into an {@link OutputStream}.
*
* @param outputStream OutputStream to use.
* @param saxBuffer A SaxBuffer containing the SAX events.
*/
public static void toOutputStream(final OutputStream outputStream, final SAXBuffer saxBuffer) {
try {
TransformerHandler transformerHandler = SAX_TRANSFORMER_FACTORY.newTransformerHandler();
Properties properties = new Properties();
properties.put("method", "xml");
transformerHandler.getTransformer().setOutputProperties(properties);
transformerHandler.setResult(new StreamResult(outputStream));
transformerHandler.startDocument();
saxBuffer.toSAX(new EmbeddedSAXPipe(transformerHandler));
transformerHandler.endDocument();
} catch (Exception e) {
throw new ProcessingException("Can't stream the provided SaxBuffer.", e);
}
}
/**
* Use a SAX parser and read the content of an {@link InputStream} into an {@link SAXConsumer}.
*
* @param inputStream InputStream containing the content to be parsed.
* @param contentHandler The ContentHandler to use.
* @throws IOException if the {@link InputStream} can't be used.
* @throws SAXException if the {@link InputStream} can't be parsed.
*/
public static void toSax(final InputStream inputStream, final ContentHandler contentHandler) throws IOException,
SAXException {
createXMLReader(contentHandler).parse(new InputSource(new BufferedInputStream(inputStream)));
}
/**
* Use a SAX parser and read the content of an {@link InputStream} into an {@link SAXConsumer}.
*
* @param string A String to be parsed.
* @param contentHandler The ContentHandler to use.
* @throws IOException if the {@link InputStream} can't be used.
* @throws SAXException if the {@link InputStream} can't be parsed.
*/
public static void toSax(final String string, final ContentHandler contentHandler) throws IOException, SAXException {
createXMLReader(contentHandler).parse(new InputSource(new StringReader(string)));
}
/**
* Stream a {@link URLConnection} into an {@link SAXConsumer} by using
* {@link XMLUtils#toSax(InputStream, ContentHandler)}. The {@link URLConnection} is closed after
* streaming.
*
* @param urlConnection The {@link URLConnection} to be streamed.
* @param contentHandler An {@link ContentHandler} as target.
*/
public static void toSax(final URLConnection urlConnection, final ContentHandler contentHandler) {
try {
InputStream inputStream = urlConnection.getInputStream();
XMLUtils.toSax(inputStream, contentHandler);
} catch (PipelineException e) {
throw e;
} catch (Exception e) {
throw new ProcessingException("Can't parse url connection " + urlConnection.getURL(), e);
} finally {
URLConnectionUtils.closeQuietly(urlConnection);
}
}
public static XMLReader createXMLReader(final ContentHandler contentHandler) {
XMLReader xmlReader;
try {
xmlReader = XMLReaderFactory.createXMLReader();
xmlReader.setContentHandler(contentHandler);
if ( contentHandler instanceof LexicalHandler ) {
xmlReader.setProperty("http://xml.org/sax/properties/lexical-handler", contentHandler);
}
xmlReader.setEntityResolver(new EntityResolver() {
public InputSource resolveEntity(String publicId, String systemId) throws SAXException, IOException {
return new InputSource(new ByteArrayInputStream("".getBytes()));
}
});
} catch (SAXException e) {
throw new ProcessingException("Cannot create and prepare an XMLReader.", e);
}
return xmlReader;
}
}