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

   1 /*
   2  * Copyright (C) 2007-2012 Mathieu Baudier
   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.slc.web.ajaxplorer.file;
  17
  18 import java.io.File;
  19 import java.io.InputStream;
  20 import java.io.OutputStream;
  21
  22 import javax.servlet.http.HttpServletRequest;
  23 import javax.servlet.http.HttpServletResponse;
  24
  25 import org.apache.commons.io.FileUtils;
  26 import org.apache.commons.io.IOUtils;
  27 import org.argeo.slc.web.ajaxplorer.AjxpAnswer;
  28 import org.argeo.slc.web.ajaxplorer.AjxpDriverException;
  29
  30 public abstract class AbstractFileDownloadAction extends FileAction {
  31         public AjxpAnswer execute(FileDriver driver, HttpServletRequest request) {
  32                 String fileStr = request.getParameter(getFileParameter());
  33                 if (fileStr == null) {
  34                         throw new AjxpDriverException(
  35                                         "A  file to download needs to be provided.");
  36                 }
  37                 File file = new File(driver.getBasePath() + fileStr);
  38                 return new AxpBasicDownloadAnswer(file);
  39         }
  40
  41         /** Return 'file' by default. */
  42         protected String getFileParameter() {
  43                 return "file";
  44         }
  45
  46         /** To be overridden. Do nothing by default. */
  47         protected void setHeaders(HttpServletResponse response, File file) {
  48                 // do nothing
  49         }
  50
  51         protected class AxpBasicDownloadAnswer implements AjxpAnswer {
  52                 private final File file;
  53
  54                 public AxpBasicDownloadAnswer(File file) {
  55                         this.file = file;
  56                 }
  57
  58                 public void updateResponse(HttpServletResponse response) {
  59                         InputStream in = null;
  60                         OutputStream out = null;
  61                         try {
  62                                 setHeaders(response, file);
  63
  64                                 if (log.isDebugEnabled())
  65                                         log.debug("Download file " + file);
  66                                 in = FileUtils.openInputStream(file);
  67                                 out = response.getOutputStream();
  68
  69                                 copyFile(in, out);
  70                                 out.flush();
  71
  72                         } catch (Exception e) {
  73                                 e.printStackTrace();
  74                                 throw new AjxpDriverException("Cannot download file " + file, e);
  75                         } finally {
  76                                 IOUtils.closeQuietly(in);
  77                                 IOUtils.closeQuietly(out);
  78                         }
  79
  80                 }
  81
  82                 protected void copyFile(InputStream in, OutputStream out)
  83                                 throws Exception {
  84                         IOUtils.copy(in, out);
  85                 }
  86
  87         }
  88 }