/*
* eXist Open Source Native XML Database
* Copyright (C) 2001-04 Wolfgang M. Meier
* wolfgang@exist-db.org
* 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.http.webdav.methods;
import java.io.IOException;
import java.io.OutputStreamWriter;
import java.io.Writer;
import javax.servlet.ServletException;
import javax.servlet.ServletOutputStream;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import org.exist.EXistException;
import org.exist.collections.Collection;
import org.exist.dom.BinaryDocument;
import org.exist.dom.DocumentImpl;
import org.exist.dom.DocumentMetadata;
import org.exist.dom.LockToken;
import org.exist.http.webdav.WebDAV;
import org.exist.security.Permission;
import org.exist.security.PermissionDeniedException;
import org.exist.security.User;
import org.exist.security.xacml.AccessContext;
import org.exist.source.ClassLoaderSource;
import org.exist.storage.BrokerPool;
import org.exist.storage.DBBroker;
import org.exist.storage.lock.Lock;
import org.exist.storage.serializers.Serializer;
import org.exist.xmldb.XmldbURI;
import org.exist.xquery.CompiledXQuery;
import org.exist.xquery.XPathException;
import org.exist.xquery.XQuery;
import org.exist.xquery.XQueryContext;
import org.exist.xquery.value.NodeValue;
import org.exist.xquery.value.Sequence;
import org.xml.sax.SAXException;
/**
* Implements the WebDAV GET method.
*
* @author wolf
*/
public class Get extends AbstractWebDAVMethod {
private final static String SERIALIZE_ERROR
= "Error while serializing document: ";
private final static String COLLECTION_XQ
= "org/exist/http/webdav/methods/collection.xq";
// We use an XQuery to list collection contents
private CompiledXQuery compiled = null;
public Get(BrokerPool pool) {
super(pool);
}
public void process(User user, HttpServletRequest request,
HttpServletResponse response, XmldbURI path)
throws ServletException, IOException {
DBBroker broker = null;
DocumentImpl resource = null;
Collection collection = null;
try {
broker = pool.get(user);
resource = broker.getXMLResource(path, Lock.READ_LOCK);
if(resource == null) {
collection = broker.openCollection(path, Lock.READ_LOCK);
try{
if(collection == null){
response.sendError(HttpServletResponse.SC_NOT_FOUND);
} else {
collectionListing(broker, collection, request, response);
}
return;
}finally{
if(collection != null)
collection.release(Lock.READ_LOCK);
}
//TODO : release collection lock here ?
}
if(!resource.getPermissions().validate(user, Permission.READ)) {
response.sendError(HttpServletResponse.SC_FORBIDDEN,
READ_PERMISSION_DENIED);
return;
}
LockToken token = resource.getMetadata().getLockToken();
if(token!=null && token.isNullResource() ){
response.sendError(HttpServletResponse.SC_NOT_FOUND,
"Document is a Null resource and cannot be retrieved");
return;
}
DocumentMetadata metadata = resource.getMetadata();
response.setContentType(metadata.getMimeType());
response.addDateHeader("Last-Modified", metadata.getLastModified());
response.addDateHeader("Created", metadata.getCreated());
// response.setContentLength(resource.getContentLength());
ServletOutputStream os = response.getOutputStream();
if(resource.getResourceType() == DocumentImpl.XML_FILE) {
Serializer serializer = broker.getSerializer();
serializer.reset();
try {
serializer.setProperties(WebDAV.OUTPUT_PROPERTIES);
Writer w = new OutputStreamWriter(os,"UTF-8");
serializer.serialize(resource,w);
w.flush();
w.close();
} catch (SAXException e) {
LOG.error(e);
throw new ServletException(SERIALIZE_ERROR + e.getMessage(), e);
}
} else {
broker.readBinaryResource((BinaryDocument) resource, os);
os.flush();
}
// os.flush();
} catch (EXistException e) {
throw new ServletException(SERIALIZE_ERROR + e.getMessage(), e);
} catch (PermissionDeniedException e) {
LOG.error(e);
response.sendError(HttpServletResponse.SC_FORBIDDEN, READ_PERMISSION_DENIED);
return;
} finally {
if(resource != null)
resource.getUpdateLock().release(Lock.READ_LOCK);
if(collection != null)
collection.release(Lock.READ_LOCK);
pool.release(broker);
}
}
/**
* Display a listing of the collection contents.
*
* @param collection
* @param response
* @throws IOException
*/
private void collectionListing(DBBroker broker, Collection collection,
HttpServletRequest request, HttpServletResponse response)
throws ServletException, IOException {
// the collection listing is generated by an XQuery
XQuery xquery = broker.getXQueryService();
XQueryContext context;
try {
if(compiled == null)
context = xquery.newContext(AccessContext.WEBDAV);
else {
compiled.reset();
context = compiled.getContext();
}
context.declareVariable("collection", collection.getURI().toString() );
context.declareVariable("uri", request.getRequestURI().toString() );
if(compiled == null){
compiled = xquery.compile(
context, new ClassLoaderSource(COLLECTION_XQ));
}
Sequence result = xquery.execute(compiled, null);
Serializer serializer = broker.getSerializer();
serializer.reset();
serializer.setProperties(WebDAV.OUTPUT_PROPERTIES);
String content = serializer.serialize((NodeValue)result.itemAt(0));
byte[] contentData = content.getBytes("UTF-8");
response.setContentType("text/html; charset=UTF-8");
response.setContentLength(contentData.length);
response.addDateHeader("Last-Modified", collection.getCreationTime());
response.addDateHeader("Created", collection.getCreationTime());
ServletOutputStream os = response.getOutputStream();
os.write(contentData);
os.flush();
} catch (XPathException e) {
LOG.error("Failed to compile xquery", e);
throw new ServletException("Failed to compile xquery", e);
} catch (SAXException e) {
LOG.error("Failed to serialize query results", e);
throw new ServletException("Failed to serialize query results", e);
}
}
}