Java tutorial
/* * eID Digital Signature Service Project. * Copyright (C) 2010 FedICT. * * This is free software; you can redistribute it and/or modify it * under the terms of the GNU Lesser General Public License version * 3.0 as published by the Free Software Foundation. * * This software 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 software; if not, see * http://www.gnu.org/licenses/. */ package be.fedict.eid.dss.sp.servlet; import java.io.IOException; import javax.servlet.ServletException; import javax.servlet.ServletOutputStream; import javax.servlet.http.HttpServlet; import javax.servlet.http.HttpServletRequest; import javax.servlet.http.HttpServletResponse; import javax.servlet.http.HttpSession; import org.apache.commons.logging.Log; import org.apache.commons.logging.LogFactory; public class DownloadServlet extends HttpServlet { private static final long serialVersionUID = 1L; private static final Log LOG = LogFactory.getLog(DownloadServlet.class); @Override protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException { LOG.debug("doGet"); HttpSession httpSession = request.getSession(); byte[] document = (byte[]) httpSession.getAttribute("document"); response.setHeader("Cache-Control", "no-cache, no-store, must-revalidate, max-age=-1"); // http 1.1 if (!request.getScheme().equals("https")) { // else the download fails in IE response.setHeader("Pragma", "no-cache"); // http 1.0 } else { response.setHeader("Pragma", "public"); } response.setDateHeader("Expires", -1); response.setContentLength(document.length); String contentType = (String) httpSession.getAttribute("ContentType"); LOG.debug("content-type: " + contentType); response.setContentType(contentType); response.setContentLength(document.length); ServletOutputStream out = response.getOutputStream(); out.write(document); out.flush(); } }