FileHandler.java

   1 package org.argeo.eclipse.ui.specific;
   2
   3 import java.net.URL;
   4
   5 import org.apache.commons.logging.Log;
   6 import org.apache.commons.logging.LogFactory;
   7 import org.eclipse.rwt.RWT;
   8 import org.eclipse.rwt.service.IServiceHandler;
   9 import org.eclipse.rwt.service.IServiceManager;
  10 import org.eclipse.ui.PlatformUI;
  11
  12 /**
  13  * RAP SPECIFIC handler to enable the opening of a download dialog box triggered
  14  * by whatever action in the UI
  15  *
  16  * Manages the registration of the effective DownloadServiceHandler at
  17  * instantiation time.
  18  *
  19  * Manages the process of forwarding the request to the handler at runtime to
  20  * open the dialog box
  21  *
  22  */
  23 public class FileHandler {
  24         public final static String FORCED_DOWNLOAD_URL_BASE_PROPERTY = "argeo.rap.specific.forcedDownloadUrlBase";
  25
  26         private final static Log log = LogFactory.getLog(FileHandler.class);
  27
  28         public FileHandler(FileProvider provider) {
  29                 // Instantiate and register the DownloadServicHandler.
  30                 IServiceManager manager = RWT.getServiceManager();
  31                 IServiceHandler handler = new DownloadServiceHandler(provider);
  32                 manager.registerServiceHandler("downloadServiceHandler", handler);
  33         }
  34
  35         public void openFile(String fileName, String fileId) {
  36
  37                 // See RAP FAQ:
  38                 // http://wiki.eclipse.org/RAP/FAQ#How_to_provide_download_link.3F
  39                 // And forum discussion :
  40                 // http://www.eclipse.org/forums/index.php?t=msg&th=205487&start=0&S=43d85dacc88b505402420592109c7240
  41
  42                 try {
  43                         if (log.isTraceEnabled())
  44                                 log.trace("URL : " + createFullDownloadUrl(fileName, fileId));
  45
  46                         URL url = new URL(createFullDownloadUrl(fileName, fileId));
  47                         PlatformUI.getWorkbench().getBrowserSupport()
  48                                         .createBrowser("DownloadDialog").openURL(url);
  49                 } catch (Exception e) {
  50                         e.printStackTrace();
  51                 }
  52
  53                 // These lines are useless in the current use case but might be
  54                 // necessary with new browsers. Stored here for memo
  55                 // response.setContentType("application/force-download");
  56                 // response.setHeader("Content-Disposition", contentDisposition);
  57                 // response.setHeader("Content-Transfer-Encoding", "binary");
  58                 // response.setHeader("Pragma", "no-cache");
  59                 // response.setHeader("Cache-Control", "no-cache, must-revalidate");
  60         }
  61
  62         private String createFullDownloadUrl(String fileName, String fileId) {
  63                 StringBuilder url = new StringBuilder();
  64                 // in case RAP is proxied we need to specify the actual base URL
  65                 // TODO find a cleaner way
  66                 String forcedDownloadUrlBase = System
  67                                 .getProperty(FORCED_DOWNLOAD_URL_BASE_PROPERTY);
  68                 if (forcedDownloadUrlBase != null)
  69                         url.append(forcedDownloadUrlBase);
  70                 else
  71                         url.append(RWT.getRequest().getRequestURL());
  72                 url.append(createParamUrl(fileName, fileId));
  73                 return url.toString();
  74         }
  75
  76         private String createParamUrl(String filename, String fileId) {
  77                 StringBuilder url = new StringBuilder();
  78                 url.append("?");
  79                 url.append(IServiceHandler.REQUEST_PARAM);
  80                 url.append("=downloadServiceHandler");
  81                 url.append("&filename=");
  82                 url.append(filename);
  83                 url.append("&fileid=");
  84                 url.append(fileId);
  85                 String encodedURL = RWT.getResponse().encodeURL(url.toString());
  86                 return encodedURL;
  87         }
  88 }