Java tutorial
/* This file is part of Subsonic. Subsonic is free software: you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation, either version 3 of the License, or (at your option) any later version. Subsonic is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for more details. You should have received a copy of the GNU General Public License along with Subsonic. If not, see <http://www.gnu.org/licenses/>. Copyright 2009 (C) Sindre Mehus */ package org.madsonic.controller; import org.madsonic.Logger; import org.madsonic.domain.MediaFile; import org.madsonic.domain.PlayQueue; import org.madsonic.domain.Player; import org.madsonic.domain.Playlist; import org.madsonic.domain.TransferStatus; import org.madsonic.domain.User; import org.madsonic.io.RangeOutputStream; import org.madsonic.service.MediaFileService; import org.madsonic.service.PlayerService; import org.madsonic.service.PlaylistService; import org.madsonic.service.SecurityService; import org.madsonic.service.SettingsService; import org.madsonic.service.StatusService; import org.madsonic.util.FileUtil; import org.madsonic.util.HttpRange; import org.madsonic.util.StringUtil; import org.madsonic.util.Util; import org.apache.commons.io.FilenameUtils; import org.apache.commons.io.IOUtils; import org.apache.commons.lang.math.LongRange; import org.apache.http.util.EncodingUtils; import org.apache.tools.zip.ZipEntry; import org.apache.tools.zip.ZipOutputStream; import org.springframework.web.bind.ServletRequestBindingException; import org.springframework.web.bind.ServletRequestUtils; import org.springframework.web.servlet.ModelAndView; import org.springframework.web.servlet.mvc.Controller; import org.springframework.web.servlet.mvc.LastModified; import javax.servlet.http.HttpServletRequest; import javax.servlet.http.HttpServletResponse; import java.io.BufferedInputStream; import java.io.File; import java.io.FileInputStream; import java.io.IOException; import java.io.InputStream; import java.io.OutputStream; import java.io.UnsupportedEncodingException; import java.util.ArrayList; import java.util.Arrays; import java.util.List; import java.util.zip.CRC32; /** * A controller used for downloading files to a remote client. If the requested path refers to a file, the * given file is downloaded. If the requested path refers to a directory, the entire directory (including * sub-directories) are downloaded as an uncompressed zip-file. * * @author Sindre Mehus */ public class DownloadController implements Controller, LastModified { private static final Logger LOG = Logger.getLogger(DownloadController.class); private PlayerService playerService; private StatusService statusService; private SecurityService securityService; private PlaylistService playlistService; private SettingsService settingsService; private MediaFileService mediaFileService; public long getLastModified(HttpServletRequest request) { try { MediaFile mediaFile = getMediaFile(request); if (mediaFile == null || mediaFile.isDirectory() || mediaFile.getChanged() == null) { return -1; } return mediaFile.getChanged().getTime(); } catch (ServletRequestBindingException e) { return -1; } } public ModelAndView handleRequest(HttpServletRequest request, HttpServletResponse response) throws Exception { TransferStatus status = null; try { status = statusService.createDownloadStatus(playerService.getPlayer(request, response, false, false)); MediaFile mediaFile = getMediaFile(request); Integer playlistId = ServletRequestUtils.getIntParameter(request, "playlist"); String playerId = request.getParameter("player"); int[] indexes = request.getParameter("i") == null ? null : ServletRequestUtils.getIntParameters(request, "i"); if (mediaFile != null) { response.setIntHeader("ETag", mediaFile.getId()); response.setHeader("Accept-Ranges", "bytes"); } HttpRange range = HttpRange.valueOf(request.getHeader("Range")); if (range != null) { response.setStatus(HttpServletResponse.SC_PARTIAL_CONTENT); LOG.info("Got HTTP range: " + range); } if (mediaFile != null) { if (mediaFile.isFile()) { downloadFile(response, status, mediaFile.getFile(), range); } else { List<MediaFile> children = mediaFileService.getChildrenOf(mediaFile, true, true, true); String zipFileName = FilenameUtils.getBaseName(mediaFile.getPath()) + ".zip"; downloadFiles(response, status, children, indexes, range, zipFileName); } } else if (playlistId != null) { List<MediaFile> songs = playlistService.getFilesInPlaylist(playlistId); Playlist playlist = playlistService.getPlaylist(playlistId); downloadFiles(response, status, songs, null, range, playlist.getName() + ".zip"); } else if (playerId != null) { Player player = playerService.getPlayerById(playerId); PlayQueue playQueue = player.getPlayQueue(); playQueue.setName("Playlist"); downloadFiles(response, status, playQueue.getFiles(), indexes, range, "download.zip"); } } finally { if (status != null) { statusService.removeDownloadStatus(status); User user = securityService.getCurrentUser(request); securityService.updateUserByteCounts(user, 0L, status.getBytesTransfered(), 0L); } } return null; } private MediaFile getMediaFile(HttpServletRequest request) throws ServletRequestBindingException { Integer id = ServletRequestUtils.getIntParameter(request, "id"); return id == null ? null : mediaFileService.getMediaFile(id); } /** * Downloads a single file. * * @param response The HTTP response. * @param status The download status. * @param file The file to download. * @param range The byte range, may be <code>null</code>. * @throws IOException If an I/O error occurs. */ private void downloadFile(HttpServletResponse response, TransferStatus status, File file, HttpRange range) throws IOException { LOG.info("Starting to download '" + FileUtil.getShortPath(file) + "' to " + status.getPlayer()); status.setFile(file); response.setContentType("application/x-download"); response.setHeader("Content-Disposition", "attachment; filename*=UTF-8''" + encodeAsRFC5987(file.getName())); if (range == null) { Util.setContentLength(response, file.length()); } copyFileToStream(file, RangeOutputStream.wrap(response.getOutputStream(), range), status, range); LOG.info("Downloaded '" + FileUtil.getShortPath(file) + "' to " + status.getPlayer()); } private String encodeAsRFC5987(String string) throws UnsupportedEncodingException { byte[] stringAsByteArray = string.getBytes("UTF-8"); char[] digits = { '0', '1', '2', '3', '4', '5', '6', '7', '8', '9', 'A', 'B', 'C', 'D', 'E', 'F' }; byte[] attrChar = { '!', '#', '$', '&', '+', '-', '.', '^', '_', '`', '|', '~', '0', '1', '2', '3', '4', '5', '6', '7', '8', '9', 'A', 'B', 'C', 'D', 'E', 'F', 'G', 'H', 'I', 'J', 'K', 'L', 'M', 'N', 'O', 'P', 'Q', 'R', 'S', 'T', 'U', 'V', 'W', 'X', 'Y', 'Z', 'a', 'b', 'c', 'd', 'e', 'f', 'g', 'h', 'i', 'j', 'k', 'l', 'm', 'n', 'o', 'p', 'q', 'r', 's', 't', 'u', 'v', 'w', 'x', 'y', 'z' }; StringBuilder sb = new StringBuilder(); for (byte b : stringAsByteArray) { if (Arrays.binarySearch(attrChar, b) >= 0) { sb.append((char) b); } else { sb.append('%'); sb.append(digits[0x0f & (b >>> 4)]); sb.append(digits[b & 0x0f]); } } return sb.toString(); } /** * Downloads a collection of files within a directory. * * @param response The HTTP response. * @param status The download status. * @param dir The directory. * @param indexes Only download files with these indexes within the directory. * @throws IOException If an I/O error occurs. */ private void downloadFiles(HttpServletResponse response, TransferStatus status, File dir, int[] indexes) throws IOException { String zipFileName = dir.getName() + ".zip"; LOG.info("Starting to download '" + zipFileName + "' to " + status.getPlayer()); status.setFile(dir); response.setContentType("application/x-download"); response.setHeader("Content-Disposition", "attachment; filename*=UTF-8''" + encodeAsRFC5987(zipFileName)); ZipOutputStream out = new ZipOutputStream(response.getOutputStream()); out.setMethod(ZipOutputStream.STORED); // No compression. MediaFile parent = mediaFileService.getMediaFile(dir); List<MediaFile> allChildren = mediaFileService.getChildrenOf(parent, true, true, true); List<MediaFile> mediaFiles = new ArrayList<MediaFile>(); for (int index : indexes) { mediaFiles.add(allChildren.get(index)); } for (MediaFile mediaFile : mediaFiles) { zip(out, mediaFile.getParentFile(), mediaFile.getFile(), status, null); } out.close(); LOG.info("Downloaded '" + zipFileName + "' to " + status.getPlayer()); } /** * Downloads all files in a directory (including sub-directories). The files are packed together in an * uncompressed zip-file. * * @param response The HTTP response. * @param status The download status. * @param file The file to download. * @param range The byte range, may be <code>null</code>. * @throws IOException If an I/O error occurs. */ private void downloadDirectory(HttpServletResponse response, TransferStatus status, File file, HttpRange range) throws IOException { String zipFileName = file.getName() + ".zip"; LOG.info("Starting to download '" + zipFileName + "' to " + status.getPlayer()); response.setContentType("application/x-download"); response.setHeader("Content-Disposition", "attachment; filename*=UTF-8''" + encodeAsRFC5987(zipFileName)); ZipOutputStream out = new ZipOutputStream(RangeOutputStream.wrap(response.getOutputStream(), range)); out.setMethod(ZipOutputStream.STORED); // No compression. zip(out, file.getParentFile(), file, status, range); out.close(); LOG.info("Downloaded '" + zipFileName + "' to " + status.getPlayer()); } /** * Downloads the given files. The files are packed together in an * uncompressed zip-file. * * @param response The HTTP response. * @param status The download status. * @param files The files to download. * @param indexes Only download songs at these indexes. May be <code>null</code>. * @param range The byte range, may be <code>null</code>. * @param zipFileName The name of the resulting zip file. * @throws IOException If an I/O error occurs. */ private void downloadFiles(HttpServletResponse response, TransferStatus status, List<MediaFile> files, int[] indexes, HttpRange range, String zipFileName) throws IOException { if (indexes != null && indexes.length == 1) { downloadFile(response, status, files.get(indexes[0]).getFile(), range); return; } LOG.info("Starting to download '" + zipFileName + "' to " + status.getPlayer()); response.setContentType("application/x-download"); response.setHeader("Content-Disposition", "attachment; filename*=UTF-8''" + encodeAsRFC5987(zipFileName)); ZipOutputStream out = new ZipOutputStream(RangeOutputStream.wrap(response.getOutputStream(), range)); out.setMethod(ZipOutputStream.STORED); // No compression. List<MediaFile> filesToDownload = new ArrayList<MediaFile>(); if (indexes == null) { filesToDownload.addAll(files); } else { for (int index : indexes) { try { filesToDownload.add(files.get(index)); } catch (IndexOutOfBoundsException x) { /* Ignored */} } } for (MediaFile mediaFile : filesToDownload) { zip(out, mediaFile.getParentFile(), mediaFile.getFile(), status, range); } out.close(); LOG.info("Downloaded '" + zipFileName + "' to " + status.getPlayer()); } /** * Utility method for writing the content of a given file to a given output stream. * * @param file The file to copy. * @param out The output stream to write to. * @param status The download status. * @param range The byte range, may be <code>null</code>. * @throws IOException If an I/O error occurs. */ private void copyFileToStream(File file, OutputStream out, TransferStatus status, HttpRange range) throws IOException { LOG.info("Downloading '" + FileUtil.getShortPath(file) + "' to " + status.getPlayer()); final int bufferSize = 16 * 1024; // 16 Kbit InputStream in = new BufferedInputStream(new FileInputStream(file), bufferSize); try { byte[] buf = new byte[bufferSize]; long bitrateLimit = 0; long lastLimitCheck = 0; while (true) { long before = System.currentTimeMillis(); int n = in.read(buf); if (n == -1) { break; } out.write(buf, 0, n); // Don't sleep if outside range. if (range != null && !range.contains(status.getBytesSkipped() + status.getBytesTransfered())) { status.addBytesSkipped(n); continue; } status.addBytesTransfered(n); long after = System.currentTimeMillis(); // Calculate bitrate limit every 5 seconds. if (after - lastLimitCheck > 5000) { bitrateLimit = 1024L * settingsService.getDownloadBitrateLimit() / Math.max(1, statusService.getAllDownloadStatuses().size()); lastLimitCheck = after; } // Sleep for a while to throttle bitrate. if (bitrateLimit != 0) { long sleepTime = 8L * 1000 * bufferSize / bitrateLimit - (after - before); if (sleepTime > 0L) { try { Thread.sleep(sleepTime); } catch (Exception x) { LOG.warn("Failed to sleep.", x); } } } } } finally { out.flush(); IOUtils.closeQuietly(in); } } public static String UTF8(String s) { byte bytes[] = EncodingUtils.getBytes(s, "UTF-8"); return new String(bytes); } public static String cp866(String s) { byte bytes[] = EncodingUtils.getBytes(s, "cp866"); return new String(bytes); } public static String iso(String s) { byte bytes[] = EncodingUtils.getBytes(s, "ISO-8859-1"); return new String(bytes); } /** * Writes a file or a directory structure to a zip output stream. File entries in the zip file are relative * to the given root. * * @param out The zip output stream. * @param root The root of the directory structure. Used to create path information in the zip file. * @param file The file or directory to zip. * @param status The download status. * @param range The byte range, may be <code>null</code>. * @throws IOException If an I/O error occurs. */ private void zip(ZipOutputStream out, File root, File file, TransferStatus status, HttpRange range) throws IOException { // Exclude all hidden files starting with a "." if (file.getName().startsWith(".")) { return; } String zipName = file.getCanonicalPath().substring(root.getCanonicalPath().length() + 1); if (file.isFile()) { status.setFile(file); ZipEntry zipEntry = new ZipEntry(zipName); zipEntry.setSize(file.length()); zipEntry.setCompressedSize(file.length()); zipEntry.setCrc(computeCrc(file)); out.putNextEntry(zipEntry); copyFileToStream(file, out, status, range); out.closeEntry(); } else { ZipEntry zipEntry = new ZipEntry(zipName + '/'); zipEntry.setSize(0); zipEntry.setCompressedSize(0); zipEntry.setCrc(0); out.putNextEntry(zipEntry); out.closeEntry(); File[] children = FileUtil.listFiles(file); for (File child : children) { zip(out, root, child, status, range); } } } /** * Computes the CRC checksum for the given file. * * @param file The file to compute checksum for. * @return A CRC32 checksum. * @throws IOException If an I/O error occurs. */ private long computeCrc(File file) throws IOException { CRC32 crc = new CRC32(); InputStream in = new FileInputStream(file); try { byte[] buf = new byte[8192]; int n = in.read(buf); while (n != -1) { crc.update(buf, 0, n); n = in.read(buf); } } finally { in.close(); } return crc.getValue(); } public void setPlayerService(PlayerService playerService) { this.playerService = playerService; } public void setStatusService(StatusService statusService) { this.statusService = statusService; } public void setSecurityService(SecurityService securityService) { this.securityService = securityService; } public void setPlaylistService(PlaylistService playlistService) { this.playlistService = playlistService; } public void setSettingsService(SettingsService settingsService) { this.settingsService = settingsService; } public void setMediaFileService(MediaFileService mediaFileService) { this.mediaFileService = mediaFileService; } }