src/main/java/net/pterodactylus/demoscenemusic/core/DownloadServlet.java

   1 /*
   2  * DemosceneMusic - DownloadServlet.java - Copyright © 2012 David Roden
   3  *
   4  * This program is free software: you can redistribute it and/or modify
   5  * it under the terms of the GNU General Public License as published by
   6  * the Free Software Foundation, either version 3 of the License, or
   7  * (at your option) any later version.
   8  *
   9  * This program is distributed in the hope that it will be useful,
  10  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  11  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  12  * GNU General Public License for more details.
  13  *
  14  * You should have received a copy of the GNU General Public License
  15  * along with this program.  If not, see <http://www.gnu.org/licenses/>.
  16  */
  17
  18 package net.pterodactylus.demoscenemusic.core;
  19
  20 import java.io.File;
  21 import java.io.FileInputStream;
  22 import java.io.IOException;
  23 import java.io.InputStream;
  24 import java.io.OutputStream;
  25
  26 import javax.servlet.ServletException;
  27 import javax.servlet.http.HttpServlet;
  28 import javax.servlet.http.HttpServletRequest;
  29 import javax.servlet.http.HttpServletResponse;
  30
  31 import net.pterodactylus.demoscenemusic.data.Artist;
  32 import net.pterodactylus.demoscenemusic.data.Track;
  33 import net.pterodactylus.demoscenemusic.data.TrackDerivative;
  34 import net.pterodactylus.demoscenemusic.utils.AudioCodecs;
  35 import net.pterodactylus.util.database.DatabaseException;
  36 import net.pterodactylus.util.io.Closer;
  37 import net.pterodactylus.util.io.StreamCopier;
  38
  39 /**
  40  * {@link HttpServlet} that lets the user download a track.
  41  *
  42  * @author <a href="mailto:bombe@pterodactylus.net">David ‘Bombe’ Roden</a>
  43  */
  44 public class DownloadServlet extends HttpServlet {
  45
  46         /**
  47          * {@inheritDoc}
  48          */
  49         @Override
  50         protected void doGet(HttpServletRequest httpServletRequest, HttpServletResponse httpServletResponse) throws ServletException, IOException {
  51                 Core core = (Core) getServletContext().getAttribute("core");
  52                 try {
  53                         String derivativeId = httpServletRequest.getParameter("id");
  54                         TrackDerivative derivative = core.getDataManager().getTrackDerivativeById(derivativeId);
  55                         Track track = core.getDataManager().getTrackByDerivativeId(derivativeId);
  56                         /* TODO - checking. */
  57
  58                         /* create name of file. */
  59                         StringBuilder filename = new StringBuilder();
  60                         for (Artist artist : track.getArtists()) {
  61                                 if (filename.length() > 0) {
  62                                         filename.append(" & ");
  63                                 }
  64                                 filename.append(artist.getName());
  65                         }
  66                         filename.append(" - ");
  67                         filename.append(track.getName());
  68                         if (track.getRemix() != null) {
  69                                 filename.append(" (");
  70                                 filename.append(track.getRemix());
  71                                 filename.append(")");
  72                         }
  73                         filename.append('.').append(derivative.getProperties().get("file/extension"));
  74
  75                         /* prepare response. */
  76                         File file = core.getDataDirectory().getFile(derivativeId);
  77                         httpServletResponse.addHeader("Content-Disposition", "attachment; filename=" + filename.toString());
  78                         httpServletResponse.setContentType(AudioCodecs.codecDescriptions.get(derivative.getProperties().get("audio/codec")).mimeType);
  79                         httpServletResponse.setContentLength((int) file.length());
  80                         httpServletResponse.setStatus(HttpServletResponse.SC_OK);
  81
  82                         /* send file. */
  83                         OutputStream servletOutputStream = httpServletResponse.getOutputStream();
  84                         InputStream fileInputStream = new FileInputStream(file);
  85                         try {
  86                                 StreamCopier.copy(fileInputStream, servletOutputStream);
  87                         } finally {
  88                                 Closer.close(fileInputStream);
  89                                 Closer.close(servletOutputStream);
  90                         }
  91
  92                 } catch (DatabaseException de1) {
  93                         throw new RuntimeException("Could not load derivative.", de1);
  94                 }
  95         }
  96
  97 }