/*
* eXist Open Source Native XML Database
* Copyright (C) 2001-09 Wolfgang M. Meier
* wolfgang@exist-db.org
* http://exist.sourceforge.net
*
* This program 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
* of the License, or (at your option) any later version.
*
* This program 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 program; if not, write to the Free Software
* Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
*
* $Id: Transform.java 13189 2010-11-12 11:05:05Z shabanovd $
*/
package org.exist.xquery.functions.response;
import java.io.IOException;
import java.io.OutputStream;
import java.io.OutputStreamWriter;
import java.io.PrintWriter;
import java.util.Properties;
import org.apache.logging.log4j.LogManager;
import org.apache.logging.log4j.Logger;
import org.exist.EXistException;
import org.exist.dom.QName;
import org.exist.http.servlets.ResponseWrapper;
import org.exist.storage.BrokerPool;
import org.exist.storage.DBBroker;
import org.exist.storage.serializers.Serializer;
import org.exist.util.serializer.SAXSerializer;
import org.exist.util.serializer.SerializerPool;
import org.exist.xquery.*;
import org.exist.xquery.value.FunctionParameterSequenceType;
import org.exist.xquery.value.JavaObjectValue;
import org.exist.xquery.value.Sequence;
import org.exist.xquery.value.SequenceType;
import org.exist.xquery.value.Type;
import org.xml.sax.SAXException;
public class Stream extends BasicFunction {
private static final Logger logger = LogManager.getLogger(Stream.class);
public final static FunctionSignature signature =
new FunctionSignature(
new QName("stream", ResponseModule.NAMESPACE_URI, ResponseModule.PREFIX),
"Stream can only be used within a servlet context. It directly streams its input to the servlet's output stream. " +
"It should thus be the last statement in the XQuery.",
new SequenceType[] {
new FunctionParameterSequenceType("content", Type.ITEM, Cardinality.ZERO_OR_MORE, "The source sequence"),
new FunctionParameterSequenceType("serialization-options", Type.STRING, Cardinality.EXACTLY_ONE, "The serialization options")},
new SequenceType(Type.ITEM, Cardinality.EMPTY)
);
/**
* @param context
* @param signature
*/
public Stream(XQueryContext context, FunctionSignature signature) {
super(context, signature);
}
/* (non-Javadoc)
* @see org.exist.xquery.BasicFunction#eval(org.exist.xquery.value.Sequence[], org.exist.xquery.value.Sequence)
*/
public Sequence eval(Sequence[] args, Sequence contextSequence) throws XPathException {
if(args[0].isEmpty()) {
return Sequence.EMPTY_SEQUENCE;
}
final Sequence inputNode = args[0];
final Properties serializeOptions = new Properties();
final String serOpts = args[1].getStringValue();
final String[] contents = Option.tokenize(serOpts);
for (int i = 0; i < contents.length; i++) {
final String[] pair = Option.parseKeyValuePair(contents[i]);
if (pair == null) {
throw new XPathException(this, "Found invalid serialization option: " + contents[i]);
}
logger.info("Setting serialization property: " + pair[0] + " = " + pair[1]);
serializeOptions.setProperty(pair[0], pair[1]);
}
final ResponseModule myModule = (ResponseModule)context.getModule(ResponseModule.NAMESPACE_URI);
// response object is read from global variable $response
final Variable respVar = myModule.resolveVariable(ResponseModule.RESPONSE_VAR);
if(respVar == null)
{throw new XPathException(this, ErrorCodes.XPDY0002, "No response object found in the current XQuery context.");}
if(respVar.getValue().getItemType() != Type.JAVA_OBJECT)
{throw new XPathException(this, ErrorCodes.XPDY0002, "Variable $response is not bound to an Java object.");}
final JavaObjectValue respValue = (JavaObjectValue) respVar.getValue().itemAt(0);
if (!"org.exist.http.servlets.HttpResponseWrapper".equals(respValue.getObject().getClass().getName()))
{throw new XPathException(this, ErrorCodes.XPDY0002, signature.toString() + " can only be used within the EXistServlet or XQueryServlet");}
final ResponseWrapper response = (ResponseWrapper) respValue.getObject();
final String mediaType = serializeOptions.getProperty("media-type", "application/xml");
final String encoding = serializeOptions.getProperty("encoding", "UTF-8");
if(mediaType != null) {
response.setContentType(mediaType + "; charset=" + encoding);
}
Serializer serializer = null;
try {
final BrokerPool db = BrokerPool.getInstance();
try(final DBBroker broker = db.getBroker();
final PrintWriter output = new PrintWriter(new OutputStreamWriter(response.getOutputStream(), encoding))) {
serializer = broker.getSerializer();
serializer.reset();
final SerializerPool serializerPool = SerializerPool.getInstance();
final SAXSerializer sax = (SAXSerializer) serializerPool.borrowObject(SAXSerializer.class);
try {
sax.setOutput(output, serializeOptions);
serializer.setProperties(serializeOptions);
serializer.setSAXHandlers(sax, sax);
serializer.toSAX(inputNode, 1, inputNode.getItemCount(), false, false, 0, 0);
} catch (final SAXException e) {
e.printStackTrace();
throw new IOException(e);
} finally {
serializerPool.returnObject(sax);
}
output.flush();
}
//commit the response
response.flushBuffer();
} catch (final IOException e) {
throw new XPathException(this, "IO exception while streaming node: " + e.getMessage(), e);
} catch (final EXistException e) {
throw new XPathException(this, "Exception while streaming node: " + e.getMessage(), e);
}
return Sequence.EMPTY_SEQUENCE;
}
}