runtime/org.argeo.slc.server/src/main/java/org/argeo/slc/web/ajaxplorer/file/AbstractFileDownloadAction.java

   1 package org.argeo.slc.web.ajaxplorer.file;
   2
   3 import java.io.File;
   4 import java.io.InputStream;
   5 import java.io.OutputStream;
   6
   7 import javax.servlet.http.HttpServletRequest;
   8 import javax.servlet.http.HttpServletResponse;
   9
  10 import org.apache.commons.io.FileUtils;
  11 import org.apache.commons.io.IOUtils;
  12 import org.argeo.slc.web.ajaxplorer.AjxpAnswer;
  13 import org.argeo.slc.web.ajaxplorer.AjxpDriverException;
  14
  15 public abstract class AbstractFileDownloadAction extends FileAction {
  16         public AjxpAnswer execute(FileDriver driver, HttpServletRequest request) {
  17                 String fileStr = request.getParameter(getFileParameter());
  18                 if (fileStr == null) {
  19                         throw new AjxpDriverException(
  20                                         "A  file to download needs to be provided.");
  21                 }
  22                 File file = new File(driver.getBasePath() + fileStr);
  23                 return new AxpBasicDownloadAnswer(file);
  24         }
  25
  26         /** Return 'file' by default. */
  27         protected String getFileParameter() {
  28                 return "file";
  29         }
  30
  31         /** To be overridden. Do nothing by default. */
  32         protected void setHeaders(HttpServletResponse response, File file) {
  33                 // do nothing
  34         }
  35
  36         protected class AxpBasicDownloadAnswer implements AjxpAnswer {
  37                 private final File file;
  38
  39                 public AxpBasicDownloadAnswer(File file) {
  40                         this.file = file;
  41                 }
  42
  43                 public void updateResponse(HttpServletResponse response) {
  44                         InputStream in = null;
  45                         OutputStream out = null;
  46                         try {
  47                                 setHeaders(response, file);
  48
  49                                 if (log.isDebugEnabled())
  50                                         log.debug("Download file " + file);
  51                                 in = FileUtils.openInputStream(file);
  52                                 out = response.getOutputStream();
  53
  54                                 copyFile(in, out);
  55                                 out.flush();
  56
  57                         } catch (Exception e) {
  58                                 e.printStackTrace();
  59                                 throw new AjxpDriverException("Cannot download file " + file, e);
  60                         } finally {
  61                                 IOUtils.closeQuietly(in);
  62                                 IOUtils.closeQuietly(out);
  63                         }
  64
  65                 }
  66
  67                 protected void copyFile(InputStream in, OutputStream out)
  68                                 throws Exception {
  69                         IOUtils.copy(in, out);
  70                 }
  71
  72         }
  73 }