/*
* eXist Open Source Native XML Database
* Copyright (C) 2006-2012 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 library; if not, write to the Free Software
* Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
*
* $Id$
*/
package org.exist.atom.modules;
import java.io.IOException;
import java.io.OutputStream;
import java.io.OutputStreamWriter;
import java.io.Writer;
import java.util.Properties;
import org.apache.logging.log4j.LogManager;
import org.apache.logging.log4j.Logger;
import org.exist.EXistException;
import org.exist.atom.Atom;
import org.exist.atom.IncomingMessage;
import org.exist.atom.OutgoingMessage;
import org.exist.collections.Collection;
import org.exist.dom.persistent.BinaryDocument;
import org.exist.dom.persistent.DocumentImpl;
import org.exist.http.BadRequestException;
import org.exist.http.NotFoundException;
import org.exist.security.Permission;
import org.exist.security.PermissionDeniedException;
import org.exist.source.URLSource;
import org.exist.storage.DBBroker;
import org.exist.storage.XQueryPool;
import org.exist.storage.lock.Lock.LockMode;
import org.exist.storage.serializers.Serializer;
import org.exist.util.serializer.SAXSerializer;
import org.exist.util.serializer.SerializerPool;
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.Sequence;
import org.xml.sax.SAXException;
/**
*
* @author R. Alexander Milowski
*/
public class AtomFeeds extends AtomModuleBase implements Atom {
protected final static Logger LOG = LogManager.getLogger(AtomProtocol.class);
static final String FEED_DOCUMENT_NAME = ".feed.atom";
static final XmldbURI FEED_DOCUMENT_URI = XmldbURI
.create(FEED_DOCUMENT_NAME);
URLSource entryByIdSource;
URLSource getFeedSource;
/** Creates a new instance of AtomProtocol */
public AtomFeeds() {
entryByIdSource = new URLSource(this.getClass().getResource(
"entry-by-id.xq"));
getFeedSource = new URLSource(this.getClass()
.getResource("get-feed.xq"));
}
public void doGet(DBBroker broker, IncomingMessage request,
OutgoingMessage response) throws BadRequestException,
PermissionDeniedException, NotFoundException, EXistException {
handleGet(true, broker, request, response);
}
public void doHead(DBBroker broker, IncomingMessage request,
OutgoingMessage response) throws BadRequestException,
PermissionDeniedException, NotFoundException, EXistException {
handleGet(false, broker, request, response);
}
protected void handleGet(boolean returnContent, DBBroker broker,
IncomingMessage request, OutgoingMessage response)
throws BadRequestException, PermissionDeniedException,
NotFoundException, EXistException {
DocumentImpl resource = null;
final XmldbURI pathUri = XmldbURI.create(request.getPath());
try {
resource = broker.getXMLResource(pathUri, LockMode.READ_LOCK);
if (resource == null) {
String id = request.getParameter("id");
if (id != null) {
id = id.trim();
if (id.length() == 0) {
id = null;
}
}
// Must be a collection
final Collection collection = broker.getCollection(pathUri);
if (collection != null) {
if (!collection.getPermissionsNoLock().validate(
broker.getCurrentSubject(), Permission.READ)) {
throw new PermissionDeniedException(
"Not allowed to read collection");
}
final DocumentImpl feedDoc = collection.getDocument(broker,
FEED_DOCUMENT_URI);
if (feedDoc == null) {
throw new BadRequestException("Collection "
+ request.getPath() + " is not an Atom feed.");
}
// Return the collection feed
// String charset = getContext().getDefaultCharset();
if (returnContent) {
if (id == null) {
response.setStatusCode(200);
getFeed(broker, request.getPath(), response);
} else {
response.setStatusCode(200);
getEntryById(broker, request.getPath(), id,
response);
}
} else {
response.setStatusCode(204);
}
} else {
throw new NotFoundException("Resource " + request.getPath()
+ " not found");
}
} else {
// Do we have permission to read the resource
if (!resource.getPermissions().validate(broker.getCurrentSubject(),
Permission.READ)) {
throw new PermissionDeniedException(
"Not allowed to read resource");
}
if (returnContent) {
response.setStatusCode(200);
if (resource.getResourceType() == DocumentImpl.BINARY_FILE) {
response.setContentType(resource.getMetadata()
.getMimeType());
try {
final OutputStream os = response.getOutputStream();
broker.readBinaryResource(
(BinaryDocument) resource, os);
os.flush();
} catch (final IOException ex) {
LOG.fatal(
"Cannot read resource " + request.getPath(),
ex);
throw new EXistException(
"I/O error on read of resource "
+ request.getPath(), ex);
}
} else {
// xml resource
final Serializer serializer = broker.getSerializer();
serializer.reset();
final String charset = getContext().getDefaultCharset();
// Serialize the document
try {
response.setContentType(resource.getMetadata()
.getMimeType() + "; charset=" + charset);
final Writer w = new OutputStreamWriter(
response.getOutputStream(), charset);
serializer.serialize(resource, w);
w.flush();
w.close();
} catch (final IOException ex) {
LOG.fatal(
"Cannot read resource " + request.getPath(),
ex);
throw new EXistException(
"I/O error on read of resource "
+ request.getPath(), ex);
} catch (final SAXException saxe) {
LOG.warn(saxe);
throw new BadRequestException(
"Error while serializing XML: "
+ saxe.getMessage());
}
}
} else {
response.setStatusCode(204);
}
}
} finally {
if (resource != null) {
resource.getUpdateLock().release(LockMode.READ_LOCK);
}
}
}
public void getEntryById(DBBroker broker, String path, String id,
OutgoingMessage response) throws EXistException,
BadRequestException, PermissionDeniedException {
final XQuery xquery = broker.getBrokerPool().getXQueryService();
final XQueryPool xqueryPool = broker.getBrokerPool().getXQueryPool();
CompiledXQuery feedQuery = xqueryPool.borrowCompiledXQuery(
broker, entryByIdSource);
XQueryContext context;
if (feedQuery == null) {
context = new XQueryContext(broker.getBrokerPool());
try {
feedQuery = xquery.compile(broker, context, entryByIdSource);
} catch (final XPathException ex) {
throw new EXistException("Cannot compile xquery "
+ entryByIdSource.getURL(), ex);
} catch (final IOException ex) {
throw new EXistException(
"I/O exception while compiling xquery "
+ entryByIdSource.getURL(), ex);
}
} else {
context = feedQuery.getContext();
}
context.setStaticallyKnownDocuments(new XmldbURI[] { XmldbURI.create(
path).append(AtomProtocol.FEED_DOCUMENT_NAME) });
try {
context.declareVariable("id", id);
final Sequence resultSequence = xquery.execute(broker, feedQuery, null);
if (resultSequence.isEmpty()) {
throw new BadRequestException("No topic was found.");
}
final String charset = getContext().getDefaultCharset();
response.setContentType("application/atom+xml; charset=" + charset);
final Serializer serializer = broker.getSerializer();
serializer.reset();
try {
final Writer w = new OutputStreamWriter(response.getOutputStream(), charset);
final SAXSerializer sax = (SAXSerializer) SerializerPool.getInstance().borrowObject(SAXSerializer.class);
final Properties outputProperties = new Properties();
sax.setOutput(w, outputProperties);
serializer.setProperties(outputProperties);
serializer.setSAXHandlers(sax, sax);
serializer.toSAX(resultSequence);
SerializerPool.getInstance().returnObject(sax);
w.flush();
w.close();
} catch (final IOException ex) {
LOG.fatal("Cannot read resource " + path, ex);
throw new EXistException("I/O error on read of resource "
+ path, ex);
} catch (final SAXException saxe) {
LOG.warn(saxe);
throw new BadRequestException("Error while serializing XML: "
+ saxe.getMessage());
}
resultSequence.itemAt(0);
} catch (final XPathException ex) {
throw new EXistException("Cannot execute xquery "
+ entryByIdSource.getURL(), ex);
} finally {
xqueryPool.returnCompiledXQuery(entryByIdSource, feedQuery);
}
}
public void getFeed(DBBroker broker, String path, OutgoingMessage response)
throws EXistException, BadRequestException,
PermissionDeniedException {
final XQuery xquery = broker.getBrokerPool().getXQueryService();
final XQueryPool xqueryPool = broker.getBrokerPool().getXQueryPool();
CompiledXQuery feedQuery = xqueryPool.borrowCompiledXQuery(
broker, getFeedSource);
XQueryContext context;
if (feedQuery == null) {
context = new XQueryContext(broker.getBrokerPool());
try {
feedQuery = xquery.compile(broker, context, getFeedSource);
} catch (final XPathException ex) {
throw new EXistException("Cannot compile xquery "
+ getFeedSource.getURL(), ex);
} catch (final IOException ex) {
throw new EXistException(
"I/O exception while compiling xquery "
+ getFeedSource.getURL(), ex);
}
} else {
context = feedQuery.getContext();
}
context.setStaticallyKnownDocuments(
new XmldbURI[] {
XmldbURI.create(path).append(AtomProtocol.FEED_DOCUMENT_NAME)
}
);
try {
final Sequence resultSequence = xquery.execute(broker, feedQuery, null);
if (resultSequence.isEmpty()) {
throw new BadRequestException("No feed was found.");
}
final String charset = getContext().getDefaultCharset();
response.setContentType("application/atom+xml; charset=" + charset);
final Serializer serializer = broker.getSerializer();
serializer.reset();
try {
final Writer w = new OutputStreamWriter(response.getOutputStream(), charset);
final SAXSerializer sax = (SAXSerializer) SerializerPool.getInstance().borrowObject(SAXSerializer.class);
final Properties outputProperties = new Properties();
sax.setOutput(w, outputProperties);
serializer.setProperties(outputProperties);
serializer.setSAXHandlers(sax, sax);
serializer.toSAX(resultSequence, 1, 1, false, false, 0, 0);
SerializerPool.getInstance().returnObject(sax);
w.flush();
w.close();
} catch (final IOException ex) {
LOG.fatal("Cannot read resource " + path, ex);
throw new EXistException("I/O error on read of resource " + path, ex);
} catch (final SAXException saxe) {
LOG.warn(saxe);
throw new BadRequestException("Error while serializing XML: " + saxe.getMessage());
}
resultSequence.itemAt(0);
} catch (final XPathException ex) {
throw new EXistException("Cannot execute xquery " + getFeedSource.getURL(), ex);
} finally {
xqueryPool.returnCompiledXQuery(getFeedSource, feedQuery);
}
}
}