org.argeo.eclipse.ui.rap/src/org/argeo/eclipse/ui/specific/OpenFileService.java

   1 package org.argeo.eclipse.ui.specific;
   2
   3 import static org.argeo.eclipse.ui.util.SingleSourcingConstants.FILE_SCHEME;
   4 import static org.argeo.eclipse.ui.util.SingleSourcingConstants.SCHEME_HOST_SEPARATOR;
   5
   6 import java.io.IOException;
   7 import java.nio.file.Files;
   8 import java.nio.file.Path;
   9 import java.nio.file.Paths;
  10
  11 import javax.servlet.ServletException;
  12 import javax.servlet.http.HttpServletRequest;
  13 import javax.servlet.http.HttpServletResponse;
  14
  15 import org.argeo.eclipse.ui.EclipseUiUtils;
  16 import org.argeo.eclipse.ui.util.SingleSourcingConstants;
  17 import org.eclipse.rap.rwt.service.ServiceHandler;
  18
  19 /**
  20  * RWT specific Basic Default service handler that retrieves a file on the
  21  * server file system using its absolute path and forwards it to the end user
  22  * browser.
  23  *
  24  * Clients might extend to provide context specific services
  25  */
  26 public class OpenFileService implements ServiceHandler {
  27         public OpenFileService() {
  28         }
  29
  30         public void service(HttpServletRequest request, HttpServletResponse response) throws IOException, ServletException {
  31                 String fileName = request.getParameter(SingleSourcingConstants.PARAM_FILE_NAME);
  32                 String uri = request.getParameter(SingleSourcingConstants.PARAM_FILE_URI);
  33
  34                 // Use buffered array to directly write the stream?
  35                 if (!uri.startsWith(SingleSourcingConstants.FILE_SCHEME))
  36                         throw new IllegalArgumentException(
  37                                         "Open file service can only handle files that are on the server file system");
  38
  39                 // Set the Metadata
  40                 response.setContentLength((int) getFileSize(uri));
  41                 if (EclipseUiUtils.isEmpty(fileName))
  42                         fileName = getFileName(uri);
  43                 response.setContentType(getMimeType(uri, fileName));
  44                 String contentDisposition = "attachment; filename=\"" + fileName + "\"";
  45                 response.setHeader("Content-Disposition", contentDisposition);
  46
  47                 // Useless for current use
  48                 // response.setHeader("Content-Transfer-Encoding", "binary");
  49                 // response.setHeader("Pragma", "no-cache");
  50                 // response.setHeader("Cache-Control", "no-cache, must-revalidate");
  51
  52                 Path path = Paths.get(getAbsPathFromUri(uri));
  53                 Files.copy(path, response.getOutputStream());
  54
  55                 // FIXME we always use temporary files for the time being.
  56                 // the deleteOnClose file only works when the JVM is closed so we
  57                 // explicitly delete to avoid overloading the server
  58                 if (path.startsWith("/tmp"))
  59                         path.toFile().delete();
  60         }
  61
  62         protected long getFileSize(String uri) throws IOException {
  63                 if (uri.startsWith(SingleSourcingConstants.FILE_SCHEME)) {
  64                         Path path = Paths.get(getAbsPathFromUri(uri));
  65                         return Files.size(path);
  66                 }
  67                 return -1l;
  68         }
  69
  70         protected String getFileName(String uri) {
  71                 if (uri.startsWith(SingleSourcingConstants.FILE_SCHEME)) {
  72                         Path path = Paths.get(getAbsPathFromUri(uri));
  73                         return path.getFileName().toString();
  74                 }
  75                 return null;
  76         }
  77
  78         private String getAbsPathFromUri(String uri) {
  79                 if (uri.startsWith(FILE_SCHEME))
  80                         return uri.substring((FILE_SCHEME + SCHEME_HOST_SEPARATOR).length());
  81                 // else if (uri.startsWith(JCR_SCHEME))
  82                 // return uri.substring((JCR_SCHEME + SCHEME_HOST_SEPARATOR).length());
  83                 else
  84                         throw new IllegalArgumentException("Unknown URI prefix for" + uri);
  85         }
  86
  87         protected String getMimeType(String uri, String fileName) throws IOException {
  88                 if (uri.startsWith(FILE_SCHEME)) {
  89                         Path path = Paths.get(getAbsPathFromUri(uri));
  90                         String mimeType = Files.probeContentType(path);
  91                         if (EclipseUiUtils.notEmpty(mimeType))
  92                                 return mimeType;
  93                 }
  94                 return "application/octet-stream";
  95         }
  96 }