org.argeo.eclipse.ui.rap/src/org/argeo/eclipse/ui/specific/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 static org.argeo.eclipse.ui.utils.SingleSourcingConstants.FILE_SCHEME;
  19 import static org.argeo.eclipse.ui.utils.SingleSourcingConstants.SCHEME_HOST_SEPARATOR;
  20
  21 import java.io.IOException;
  22 import java.nio.file.Files;
  23 import java.nio.file.Path;
  24 import java.nio.file.Paths;
  25
  26 import javax.servlet.ServletException;
  27 import javax.servlet.http.HttpServletRequest;
  28 import javax.servlet.http.HttpServletResponse;
  29
  30 import org.argeo.eclipse.ui.EclipseUiUtils;
  31 import org.argeo.eclipse.ui.utils.SingleSourcingConstants;
  32 import org.eclipse.rap.rwt.service.ServiceHandler;
  33
  34 /**
  35  * RWT specific Basic Default service handler that retrieves a file on the
  36  * server file system using its absolute path and forwards it to the end user
  37  * browser.
  38  *
  39  * Clients might extend to provide context specific services
  40  */
  41 public class OpenFileService implements ServiceHandler {
  42         public OpenFileService() {
  43         }
  44
  45         public void service(HttpServletRequest request, HttpServletResponse response) throws IOException, ServletException {
  46                 String fileName = request.getParameter(SingleSourcingConstants.PARAM_FILE_NAME);
  47                 String uri = request.getParameter(SingleSourcingConstants.PARAM_FILE_URI);
  48
  49                 // Use buffered array to directly write the stream?
  50                 if (!uri.startsWith(SingleSourcingConstants.FILE_SCHEME))
  51                         throw new IllegalArgumentException(
  52                                         "Open file service can only handle files that are on the server file system");
  53
  54                 // Set the Metadata
  55                 response.setContentLength((int) getFileSize(uri));
  56                 if (EclipseUiUtils.isEmpty(fileName))
  57                         fileName = getFileName(uri);
  58                 response.setContentType(getMimeType(uri, fileName));
  59                 String contentDisposition = "attachment; filename=\"" + fileName + "\"";
  60                 response.setHeader("Content-Disposition", contentDisposition);
  61
  62                 // Useless for current use
  63                 // response.setHeader("Content-Transfer-Encoding", "binary");
  64                 // response.setHeader("Pragma", "no-cache");
  65                 // response.setHeader("Cache-Control", "no-cache, must-revalidate");
  66
  67                 Path path = Paths.get(getAbsPathFromUri(uri));
  68                 Files.copy(path, response.getOutputStream());
  69
  70                 // FIXME we always use temporary files for the time being.
  71                 // the deleteOnClose file only works when the JVM is closed so we
  72                 // explicitly delete to avoid overloading the server
  73                 if (path.startsWith("/tmp"))
  74                         path.toFile().delete();
  75         }
  76
  77         protected long getFileSize(String uri) throws IOException {
  78                 if (uri.startsWith(SingleSourcingConstants.FILE_SCHEME)) {
  79                         Path path = Paths.get(getAbsPathFromUri(uri));
  80                         return Files.size(path);
  81                 }
  82                 return -1l;
  83         }
  84
  85         protected String getFileName(String uri) {
  86                 if (uri.startsWith(SingleSourcingConstants.FILE_SCHEME)) {
  87                         Path path = Paths.get(getAbsPathFromUri(uri));
  88                         return path.getFileName().toString();
  89                 }
  90                 return null;
  91         }
  92
  93         private String getAbsPathFromUri(String uri) {
  94                 if (uri.startsWith(FILE_SCHEME))
  95                         return uri.substring((FILE_SCHEME + SCHEME_HOST_SEPARATOR).length());
  96                 // else if (uri.startsWith(JCR_SCHEME))
  97                 // return uri.substring((JCR_SCHEME + SCHEME_HOST_SEPARATOR).length());
  98                 else
  99                         throw new IllegalArgumentException("Unknown URI prefix for" + uri);
 100         }
 101
 102         protected String getMimeType(String uri, String fileName) throws IOException {
 103                 if (uri.startsWith(FILE_SCHEME)) {
 104                         Path path = Paths.get(getAbsPathFromUri(uri));
 105                         String mimeType = Files.probeContentType(path);
 106                         if (EclipseUiUtils.notEmpty(mimeType))
 107                                 return mimeType;
 108                 }
 109                 return "application/octet-stream";
 110         }
 111 }