/*
* eXist Open Source Native XML Database
* Copyright (C) 2001-09 The eXist Project
* http://exist-db.org
*
* 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.
*
* $Id$
*/
package org.exist.xquery.functions.response;
import org.apache.log4j.Logger;
import org.exist.dom.QName;
import org.exist.http.servlets.ResponseWrapper;
import org.exist.xquery.BasicFunction;
import org.exist.xquery.Cardinality;
import org.exist.xquery.FunctionSignature;
import org.exist.xquery.Variable;
import org.exist.xquery.XPathException;
import org.exist.xquery.XQueryContext;
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 java.io.IOException;
import java.io.OutputStream;
import org.exist.xquery.value.BinaryValue;
public class StreamBinary extends BasicFunction {
protected static final Logger logger = Logger.getLogger(StreamBinary.class);
protected static final FunctionParameterSequenceType BINARY_DATA_PARAM = new FunctionParameterSequenceType("binary-data", Type.BASE64_BINARY, Cardinality.EXACTLY_ONE, "The binary data to stream");
protected static final FunctionParameterSequenceType CONTENT_TYPE_PARAM = new FunctionParameterSequenceType("content-type", Type.STRING, Cardinality.EXACTLY_ONE, "The ContentType HTTP header value");
protected static final FunctionParameterSequenceType FILENAME_PARAM = new FunctionParameterSequenceType("filename", Type.STRING, Cardinality.ZERO_OR_ONE, "The filename. If no filename is given, then the current request name is used");
public final static FunctionSignature signature =
new FunctionSignature(
new QName("stream-binary", ResponseModule.NAMESPACE_URI, ResponseModule.PREFIX),
"Streams the binary data to the current servlet response output stream. The ContentType "
+ "HTTP header is set to the value given in $content-type."
+ "Note: the servlet output stream will be closed afterwards and mime-type settings in the prolog "
+ "will not be passed.",
new SequenceType[]{BINARY_DATA_PARAM, CONTENT_TYPE_PARAM, FILENAME_PARAM},
new SequenceType(Type.ITEM, Cardinality.EMPTY),
true);
public StreamBinary(XQueryContext context) {
super(context, signature);
}
@Override
public Sequence eval(Sequence[] args, Sequence contextSequence) throws XPathException {
if(args[0].isEmpty() || args[1].isEmpty()) {
return (Sequence.EMPTY_SEQUENCE);
}
final BinaryValue binary = (BinaryValue) args[0].itemAt(0);
final String contentType = args[1].getStringValue();
String filename = null;
if((args.length > 2) && !args[2].isEmpty()) {
filename = args[2].getStringValue();
}
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) || (respVar.getValue() == null)) {
throw (new XPathException(this, "No response object found in the current XQuery context."));
}
if(respVar.getValue().getItemType() != Type.JAVA_OBJECT) {
throw (new XPathException(this, "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, signature.toString() + " can only be used within the EXistServlet or XQueryServlet"));
}
final ResponseWrapper response = (ResponseWrapper) respValue.getObject();
response.setHeader("Content-Type", contentType);
if(filename != null) {
response.setHeader("Content-Disposition", "inline; filename=\"" + filename + "\"");
}
try {
final OutputStream os = response.getOutputStream();
binary.streamBinaryTo(response.getOutputStream());
os.close();
//commit the response
response.flushBuffer();
} catch (final IOException e) {
throw (new XPathException(this, "IO exception while streaming data: " + e.getMessage(), e));
}
return (Sequence.EMPTY_SEQUENCE);
}
}