Java tutorial
/* * #%L * Alfresco Repository WAR Community * %% * Copyright (C) 2005 - 2016 Alfresco Software Limited * %% * This file is part of the Alfresco software. * If the software was purchased under a paid Alfresco license, the terms of * the paid license agreement will prevail. Otherwise, the software is * provided under the following open source license terms: * * Alfresco 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 3 of the License, or * (at your option) any later version. * * Alfresco 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 Alfresco. If not, see <http://www.gnu.org/licenses/>. * #L% */ package org.alfresco.web.app.servlet; import java.io.IOException; import java.io.OutputStream; import java.net.SocketException; import java.util.Date; import java.util.Locale; import javax.servlet.ServletException; import javax.servlet.http.HttpServletRequest; import javax.servlet.http.HttpServletResponse; import org.alfresco.repo.content.MimetypeMap; import org.alfresco.repo.security.permissions.AccessDeniedException; import org.alfresco.service.ServiceRegistry; import org.alfresco.service.cmr.repository.ContentIOException; import org.alfresco.service.cmr.repository.ContentReader; import org.alfresco.service.cmr.repository.ContentService; import org.alfresco.service.cmr.repository.datatype.DefaultTypeConverter; import org.apache.commons.logging.Log; import org.apache.commons.logging.LogFactory; /** * A serlet that provides direct access to the content stores via a content URL. * <p> * Requests can be of the form:<br/> * <pre> * /alfresco/downloadDirect?contentUrl=some-url?ticket=auth?infoOnly=value * <b>contentUrl</b> is a ContentStore-specific URL * <b>ticket</b> is a valid authentication token for an admin user * <b>infoOnly</b> is set to true to leave off the binary stream and just send * the data about the content. * </pre> * This serlet is intended to be accessed to retrieve the binary content from * the content stores. If you wish to retrieve content from a client, use * the other content download servlets available. * <p> * The following responses are generated: * <ul> * <li><b>Contet not found:</b> 204 NO CONTENT</li> * <li><b>Access denied:</b> 403 FORBIDDEN</li> * </ul> * The following header values are set: * <ul> * <li><b>alfresco.dr.size:</b> The content size</li> * <li><b>alfresco.dr.lastModified:</b> The last modified date</li> * <li><b>alfresco.dr.mimetype:</b> The content mimetype</li> * <li><b>alfresco.dr.encoding:</b> The content encoding</li> * <li><b>alfresco.dr.locale:</b> The content locale</li> * </ul> * Note that the mimetype, encoding and locale generally fallback to the default * as implemented by the {@linkplain ContentService#getRawReader(String) raw reader}. * * @since 2.1 * @author Derek Hulley */ public class DownloadRawContentServlet extends BaseServlet { private static final long serialVersionUID = 2973080032044411358L; private static Log logger = LogFactory.getLog(DownloadRawContentServlet.class); private static final String DEFAULT_MIMETYPE = MimetypeMap.MIMETYPE_BINARY; private static final String DEFAULT_ENCODING = "utf-8"; private static final String ARG_CONTENT_URL = "contentUrl"; private static final String ARG_INFO_ONLY = "infoOnly"; protected void service(HttpServletRequest req, HttpServletResponse res) throws ServletException, IOException { if (logger.isDebugEnabled()) { logger.debug("Authenticating downloadDirect request: " + req.getRequestURI()); } AuthenticationStatus status = servletAuthenticate(req, res); if (status == AuthenticationStatus.Failure) { return; } setNoCacheHeaders(res); processRequest(req, res); } /** * Processes the request using the current context i.e. no * authentication checks are made, it is presumed they have already * been done. * * @param req The HTTP request * @param res The HTTP response */ private void processRequest(HttpServletRequest req, HttpServletResponse res) throws ServletException, IOException { String uri = req.getRequestURI(); String contentUrl = req.getParameter(ARG_CONTENT_URL); if (contentUrl == null || contentUrl.length() == 0) { throw new IllegalArgumentException( "Download URL did not contain parameter '" + ARG_CONTENT_URL + "':" + uri); } String infoOnlyStr = req.getParameter(ARG_INFO_ONLY); boolean infoOnly = (infoOnlyStr == null) ? false : Boolean.parseBoolean(infoOnlyStr); ServiceRegistry serviceRegistry = getServiceRegistry(getServletContext()); ContentService contentService = serviceRegistry.getContentService(); // Attempt to get the reader ContentReader reader = null; try { reader = contentService.getRawReader(contentUrl); // If the content doesn't exist, generate an error if (!reader.exists()) { if (logger.isDebugEnabled()) { logger.debug("Returning 204 Not Found error..."); } res.sendError(HttpServletResponse.SC_NO_CONTENT); return; } } catch (AccessDeniedException e) { if (logger.isDebugEnabled()) { logger.debug("Returning 403 Forbidden error after exception: ", e); } res.sendError(HttpServletResponse.SC_FORBIDDEN); return; } long readerSize = reader.getSize(); Date readerLastModified = new Date(reader.getLastModified()); String readerMimetype = reader.getMimetype(); String readerEncoding = reader.getEncoding(); Locale readerLocale = reader.getLocale(); // Set the content info res.setHeader("alfresco.dr.size", DefaultTypeConverter.INSTANCE.convert(String.class, readerSize)); res.setHeader("alfresco.dr.lastModified", DefaultTypeConverter.INSTANCE.convert(String.class, readerLastModified)); res.setHeader("alfresco.dr.mimetype", readerMimetype); res.setHeader("alfresco.dr.encoding", readerEncoding); res.setHeader("alfresco.dr.locale", DefaultTypeConverter.INSTANCE.convert(String.class, readerLocale)); // Pass the stream to the response, unless only the content info was requested if (infoOnly) { // Fill response details res.setContentType(DEFAULT_MIMETYPE); res.setCharacterEncoding(DEFAULT_ENCODING); } else { // Fill response details res.setContentType(readerMimetype); res.setCharacterEncoding(readerEncoding); try { OutputStream clientOs = res.getOutputStream(); reader.getContent(clientOs); // Streams closed for us } catch (SocketException e1) { // Not a problem if (logger.isDebugEnabled()) { logger.debug("Client aborted stream read:\n" + " Content URL: " + contentUrl); } } catch (ContentIOException e2) { // Not a problem if (logger.isDebugEnabled()) { logger.debug("Client aborted stream read:\n" + " Content URL: " + contentUrl); } } } } }