001/*
002 * (C) Copyright 2006-2008 Nuxeo SAS (http://nuxeo.com/) and contributors.
003 *
004 * All rights reserved. This program and the accompanying materials
005 * are made available under the terms of the GNU Lesser General Public License
006 * (LGPL) version 2.1 which accompanies this distribution, and is available at
007 * http://www.gnu.org/licenses/lgpl.html
008 *
009 * This library is distributed in the hope that it will be useful,
010 * but WITHOUT ANY WARRANTY; without even the implied warranty of
011 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
012 * Lesser General Public License for more details.
013 *
014 * Contributors:
015 *     bstefanescu
016 *
017 * $Id$
018 */
019
020package org.nuxeo.ecm.webengine.model.io;
021
022import static org.apache.commons.logging.LogFactory.getLog;
023
024import java.io.IOException;
025import java.io.OutputStream;
026import java.lang.annotation.Annotation;
027import java.lang.reflect.Type;
028
029import javax.servlet.ServletContext;
030import javax.servlet.http.HttpServletRequest;
031import javax.servlet.http.HttpServletResponse;
032import javax.ws.rs.Produces;
033import javax.ws.rs.core.Context;
034import javax.ws.rs.core.MediaType;
035import javax.ws.rs.core.MultivaluedMap;
036import javax.ws.rs.ext.MessageBodyWriter;
037import javax.ws.rs.ext.Provider;
038
039import org.apache.commons.logging.Log;
040import org.nuxeo.ecm.core.api.Blob;
041import org.nuxeo.ecm.core.io.download.BufferingServletOutputStream;
042import org.nuxeo.ecm.core.io.download.DownloadService;
043import org.nuxeo.runtime.api.Framework;
044import org.nuxeo.runtime.transaction.TransactionHelper;
045
046/**
047 * @author <a href="mailto:bs@nuxeo.com">Bogdan Stefanescu</a>
048 */
049@Provider
050@Produces({ "*/*", "text/plain" })
051public class BlobWriter implements MessageBodyWriter<Blob> {
052
053    private static final Log log = getLog(BlobWriter.class);
054
055    public static final String BLOB_ID = "blobId";
056
057    @Context
058    private HttpServletRequest request;
059
060    @Context
061    private HttpServletResponse response;
062
063    @Context
064    private ServletContext servletContext;
065
066    @Override
067    public void writeTo(Blob blob, Class<?> type, Type genericType, Annotation[] annotations, MediaType mediaType,
068            MultivaluedMap<String, Object> httpHeaders, OutputStream entityStream) throws IOException {
069        // Ensure transaction is committed before writing blob to response
070        commitAndReopenTransaction();
071        if (Framework.isTestModeSet()) {
072            transferBlob(blob, entityStream);
073        } else {
074            DownloadService downloadService = Framework.getService(DownloadService.class);
075            downloadService.downloadBlob(request, response, null, null, blob, blob.getFilename(), "webengine");
076        }
077    }
078
079    protected void commitAndReopenTransaction() {
080        if (TransactionHelper.isTransactionActiveOrMarkedRollback()) {
081            TransactionHelper.commitOrRollbackTransaction();
082            TransactionHelper.startTransaction();
083        }
084    }
085
086    protected void transferBlob(Blob blob, OutputStream entityStream) throws IOException {
087        BufferingServletOutputStream.stopBufferingThread();
088        blob.transferTo(entityStream);
089        entityStream.flush();
090    }
091
092    @Override
093    public long getSize(Blob arg0, Class<?> arg1, Type arg2, Annotation[] arg3, MediaType arg4) {
094        long n = arg0.getLength();
095        return n <= 0 ? -1 : n;
096    }
097
098    @Override
099    public boolean isWriteable(Class<?> arg0, Type type, Annotation[] arg2, MediaType arg3) {
100        return Blob.class.isAssignableFrom(arg0);
101    }
102
103}