base/runtime/org.argeo.eclipse.ui.rap/src/main/java/org/argeo/eclipse/ui/specific/DownloadServiceHandler.java

   1 /*
   2  * Copyright (C) 2007-2012 Argeo GmbH
   3  *
   4  * Licensed under the Apache License, Version 2.0 (the "License");
   5  * you may not use this file except in compliance with the License.
   6  * You may obtain a copy of the License at
   7  *
   8  *         http://www.apache.org/licenses/LICENSE-2.0
   9  *
  10  * Unless required by applicable law or agreed to in writing, software
  11  * distributed under the License is distributed on an "AS IS" BASIS,
  12  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  13  * See the License for the specific language governing permissions and
  14  * limitations under the License.
  15  */
  16 package org.argeo.eclipse.ui.specific;
  17
  18 import java.io.IOException;
  19
  20 import javax.servlet.ServletException;
  21 import javax.servlet.http.HttpServletRequest;
  22 import javax.servlet.http.HttpServletResponse;
  23
  24 import org.argeo.ArgeoException;
  25 import org.eclipse.rap.rwt.service.ServiceHandler;
  26
  27 public class DownloadServiceHandler implements ServiceHandler {
  28
  29         private FileProvider provider;
  30
  31         public DownloadServiceHandler(FileProvider provider) {
  32                 this.provider = provider;
  33         }
  34
  35         public void service(HttpServletRequest request, HttpServletResponse response)
  36                         throws IOException, ServletException {
  37                 // Which file to download?
  38                 String fileName = request.getParameter("filename");
  39                 String fileId = request.getParameter("fileid");
  40
  41                 // Get the file content
  42                 byte[] download = provider.getByteArrayFileFromId(fileId);
  43
  44                 // Send the file in the response
  45                 response.setContentType("application/octet-stream");
  46                 response.setContentLength(download.length);
  47                 String contentDisposition = "attachment; filename=\"" + fileName + "\"";
  48                 response.setHeader("Content-Disposition", contentDisposition);
  49
  50                 // Various header fields that can be set to solve some issues with some
  51                 // old browsers.
  52                 // Unused.
  53                 // String contentType = "application/force-download; name=\"" + fileName
  54                 // + "\"";
  55                 // response.setContentType(contentType);
  56                 // response.setHeader("Content-Transfer-Encoding", "binary");
  57                 // response.setHeader("Pragma", "no-cache");
  58                 // response.setHeader("Cache-Control", "no-cache, must-revalidate");
  59                 // response.setHeader("Expires", "0");
  60                 // response.setHeader("Connection", "Keep-Alive");
  61                 // response.setHeader("Keep-Alive", "timeout=5, max=86");
  62                 // response.setHeader("transfer-Encoding", "chunked");
  63
  64                 try {
  65                         response.getOutputStream().write(download);
  66                 } catch (IOException ioe) {
  67                         throw new ArgeoException("Error while writing the file " + fileName
  68                                         + " to the servlet response", ioe);
  69                 }
  70         }
  71 }