/*
* eXist Open Source Native XML Database
* Copyright (C) 2006-2009 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., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
*
* $Id$
*/
package org.exist.xquery.functions.xmldb;
import org.apache.log4j.Logger;
import org.exist.dom.DocumentImpl;
import org.exist.dom.QName;
import org.exist.storage.lock.Lock;
import org.exist.util.MimeTable;
import org.exist.util.MimeType;
import org.exist.xmldb.XmldbURI;
import org.exist.xquery.BasicFunction;
import org.exist.xquery.Cardinality;
import org.exist.xquery.FunctionSignature;
import org.exist.xquery.XPathException;
import org.exist.xquery.XQueryContext;
import org.exist.xquery.value.AnyURIValue;
import org.exist.xquery.value.FunctionReturnSequenceType;
import org.exist.xquery.value.FunctionParameterSequenceType;
import org.exist.xquery.value.Sequence;
import org.exist.xquery.value.SequenceType;
import org.exist.xquery.value.StringValue;
import org.exist.xquery.value.Type;
/**
* @author Adam Retter <adam.retter@devon.gov.uk>
*/
public class XMLDBGetMimeType extends BasicFunction {
protected static final Logger logger = Logger.getLogger(XMLDBGetMimeType.class);
public final static FunctionSignature signature =
new FunctionSignature(
new QName("get-mime-type", XMLDBModule.NAMESPACE_URI, XMLDBModule.PREFIX),
"Returns the MIME type if available of the resource $resource-uri, otherwise the empty sequence. " +
XMLDBModule.ANY_URI,
new SequenceType[] {
new FunctionParameterSequenceType("resource-uri", Type.ANY_URI, Cardinality.EXACTLY_ONE, "The resource URI")
},
new FunctionReturnSequenceType(Type.STRING, Cardinality.ZERO_OR_ONE, "the mime-type if available, otherwise the empty sequence")
);
public XMLDBGetMimeType(XQueryContext context, FunctionSignature signature)
{
super(context, signature);
}
public Sequence eval(Sequence args[], Sequence contextSequence)
throws XPathException {
final String path = new AnyURIValue(args[0].itemAt(0).getStringValue()).toString();
if(path.matches("^[a-z]+://.*")) {
//external
final MimeTable mimeTable = MimeTable.getInstance();
final MimeType mimeType = mimeTable.getContentTypeFor(path);
if(mimeType != null) {
return new StringValue(mimeType.getName());
}
} else {
//database
DocumentImpl doc = null;
try {
XmldbURI pathUri = XmldbURI.xmldbUriFor(path);
// relative collection Path: add the current base URI
pathUri = context.getBaseURI().toXmldbURI().resolveCollectionPath(pathUri);
// try to open the document and acquire a lock
doc = (DocumentImpl)context.getBroker().getXMLResource(pathUri, Lock.READ_LOCK);
if(doc != null) {
return new StringValue(((DocumentImpl)doc).getMetadata().getMimeType());
}
} catch(final Exception e) {
logger.error(e.getMessage());
throw new XPathException(this, e);
} finally {
//release all locks
if(doc != null) {
doc.getUpdateLock().release(Lock.READ_LOCK);
}
}
}
return Sequence.EMPTY_SEQUENCE;
}
}