OpenFileService.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.File;
  19 import java.io.IOException;
  20
  21 import javax.servlet.ServletException;
  22 import javax.servlet.http.HttpServletRequest;
  23 import javax.servlet.http.HttpServletResponse;
  24
  25 import org.apache.commons.io.FileUtils;
  26 import org.eclipse.rap.rwt.service.ServiceHandler;
  27
  28 /**
  29  * RWT specific Basic Default service handler that retrieves a file on the
  30  * server file system using its absolute path and forwards it to the end user
  31  * browser.
  32  *
  33  * Clients might extend to provide context specific services
  34  */
  35 public class OpenFileService implements ServiceHandler {
  36         public final static String PARAM_FILE_NAME = "param.fileName";
  37         public final static String PARAM_FILE_URI = "param.fileURI";
  38
  39         public final static String SCHEME_HOST_SEPARATOR = "://";
  40         public final static String FILE_SCHEME = "file";
  41
  42         public OpenFileService() {
  43         }
  44
  45         public void service(HttpServletRequest request, HttpServletResponse response)
  46                         throws IOException, ServletException {
  47                 String fileName = request.getParameter(PARAM_FILE_NAME);
  48                 String uri = request.getParameter(PARAM_FILE_URI);
  49
  50                 // Set the Metadata
  51                 response.setContentLength((int) getFileLength(uri));
  52                 if (fileName == null || "".equals(fileName.trim()))
  53                         fileName = getFileName(uri);
  54                 response.setContentType(getMimeTypeFromName(fileName));
  55                 String contentDisposition = "attachment; filename=\"" + fileName + "\"";
  56                 response.setHeader("Content-Disposition", contentDisposition);
  57
  58                 // Useless for current use
  59                 // response.setContentType("application/force-download");
  60                 // response.setHeader("Content-Transfer-Encoding", "binary");
  61                 // response.setHeader("Pragma", "no-cache");
  62                 // response.setHeader("Cache-Control", "no-cache, must-revalidate");
  63
  64                 // TODO use buffered array to directly write the stream?
  65                 response.getOutputStream().write(getFileAsByteArray(uri));
  66         }
  67
  68         /**
  69          * Retrieves the data as Byte Array given an uri.
  70          *
  71          * <p>
  72          * Overwrite to provide application specific abilities, among other to open
  73          * from a JCR repository
  74          * </p>
  75          */
  76         protected byte[] getFileAsByteArray(String uri) {
  77                 if (uri.startsWith(FILE_SCHEME)) {
  78                         try {
  79                                 return FileUtils.readFileToByteArray(new File(
  80                                                 getFilePathFromUri(uri)));
  81                         } catch (IOException ioe) {
  82                                 throw new SingleSourcingException("Error getting the file at "
  83                                                 + uri, ioe);
  84                         }
  85                 }
  86                 return null;
  87         }
  88
  89         protected long getFileLength(String uri) {
  90                 if (uri.startsWith(FILE_SCHEME)) {
  91                         return new File(getFilePathFromUri(uri)).length();
  92                 }
  93                 return -1l;
  94         }
  95
  96         protected String getFileName(String uri) {
  97                 if (uri.startsWith(FILE_SCHEME)) {
  98                         return new File(getFilePathFromUri(uri)).getName();
  99                 }
 100                 return null;
 101         }
 102
 103         private String getFilePathFromUri(String uri) {
 104                 return uri.substring((FILE_SCHEME + SCHEME_HOST_SEPARATOR).length());
 105         }
 106
 107         /** Overwrite to precise the content type */
 108         protected String getMimeTypeFromName(String fileName) {
 109                 return "application/octet-stream";
 110         }
 111 }