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 net.sourceforge.kalimbaradio.androidapp.service; import java.io.File; import java.io.FileOutputStream; import java.io.IOException; import java.io.InputStream; import java.io.OutputStream; import org.apache.http.HttpResponse; import org.apache.http.HttpStatus; import android.content.Context; import android.net.wifi.WifiManager; import android.os.PowerManager; import android.util.DisplayMetrics; import net.sourceforge.kalimbaradio.androidapp.domain.MusicDirectory; import net.sourceforge.kalimbaradio.androidapp.util.CacheCleaner; import net.sourceforge.kalimbaradio.androidapp.util.CancellableTask; import net.sourceforge.kalimbaradio.androidapp.util.FileUtil; import net.sourceforge.kalimbaradio.androidapp.util.Logger; import net.sourceforge.kalimbaradio.androidapp.util.Util; /** * @author Sindre Mehus * @version $Id$ */ public class DownloadFile { private static final Logger LOG = new Logger(DownloadFile.class); private final Context context; private final MusicDirectory.Entry song; private final File partialFile; private final File completeFile; private final File saveFile; private final MediaStoreService mediaStoreService; private CancellableTask downloadTask; private boolean save; private boolean failed; private int bitRate; public DownloadFile(Context context, MusicDirectory.Entry song) { this.context = context; this.song = song; saveFile = FileUtil.getSongFile(context, song); bitRate = Util.getMaxBitrate(context); partialFile = new File(saveFile.getParent(), FileUtil.getBaseName(saveFile.getName()) + "." + bitRate + ".partial." + FileUtil.getExtension(saveFile.getName())); completeFile = new File(saveFile.getParent(), FileUtil.getBaseName(saveFile.getName()) + ".complete." + FileUtil.getExtension(saveFile.getName())); mediaStoreService = new MediaStoreService(context); } public MusicDirectory.Entry getSong() { return song; } /** * Returns the effective bit rate. */ public int getBitRate() { if (bitRate > 0) { return bitRate; } return song.getBitRate() == null ? 160 : song.getBitRate(); } public synchronized void download() { FileUtil.createDirectoryForParent(saveFile); failed = false; downloadTask = new DownloadTask(); downloadTask.start(); } public synchronized void cancelDownload() { if (downloadTask != null) { downloadTask.cancel(); } } public File getCompleteFile() { if (saveFile.exists()) { return saveFile; } if (completeFile.exists()) { return completeFile; } return saveFile; } public File getPartialFile() { return partialFile; } public boolean isSaved() { return saveFile.exists(); } public synchronized boolean isCompleteFileAvailable() { return saveFile.exists() || completeFile.exists(); } public synchronized boolean isWorkDone() { return saveFile.exists() || (completeFile.exists() && !save); } public synchronized boolean isDownloading() { return downloadTask != null && downloadTask.isRunning(); } public synchronized boolean isDownloadCancelled() { return downloadTask != null && downloadTask.isCancelled(); } public boolean shouldSave() { return save; } public boolean isFailed() { return failed; } public void delete() { cancelDownload(); Util.delete(partialFile); Util.delete(completeFile); Util.delete(saveFile); mediaStoreService.deleteFromMediaStore(this); } public void unpin() { if (saveFile.exists()) { saveFile.renameTo(completeFile); } } public void pin() { if (completeFile.exists()) { completeFile.renameTo(saveFile); } else { save = true; } } public boolean cleanup() { boolean ok = true; if (completeFile.exists() || saveFile.exists()) { ok = Util.delete(partialFile); } if (saveFile.exists()) { ok &= Util.delete(completeFile); } return ok; } // In support of LRU caching. public void updateModificationDate() { updateModificationDate(saveFile); updateModificationDate(partialFile); updateModificationDate(completeFile); } private void updateModificationDate(File file) { if (file.exists()) { boolean ok = file.setLastModified(System.currentTimeMillis()); if (!ok) { LOG.warn("Failed to set last-modified date on " + file); } } } @Override public String toString() { return "DownloadFile (" + song + ")"; } private class DownloadTask extends CancellableTask { @Override public void execute() { InputStream in = null; FileOutputStream out = null; PowerManager.WakeLock wakeLock = null; WifiManager.WifiLock wifiLock = null; try { if (Util.isScreenLitOnDownload(context)) { PowerManager pm = (PowerManager) context.getSystemService(Context.POWER_SERVICE); wakeLock = pm.newWakeLock(PowerManager.SCREEN_DIM_WAKE_LOCK | PowerManager.ON_AFTER_RELEASE, toString()); wakeLock.acquire(); LOG.info("Acquired wake lock " + wakeLock); } wifiLock = Util.createWifiLock(context, toString()); wifiLock.acquire(); LOG.info("Acquired wifi lock " + wifiLock); if (saveFile.exists()) { LOG.info(saveFile + " already exists. Skipping."); return; } if (completeFile.exists()) { if (save) { Util.atomicCopy(completeFile, saveFile); } else { LOG.info(completeFile + " already exists. Skipping."); } return; } if (!FileUtil.canWriteOrCreate(partialFile)) { throw new Exception("Can't write to " + partialFile); } MusicService musicService = MusicServiceFactory.getMusicService(context); // Attempt partial HTTP GET, appending to the file if it exists. HttpResponse response = musicService.getDownloadInputStream(context, song, partialFile.length(), bitRate, DownloadTask.this); in = response.getEntity().getContent(); boolean partial = response.getStatusLine().getStatusCode() == HttpStatus.SC_PARTIAL_CONTENT; if (partial) { LOG.info("Executed partial HTTP GET, skipping " + partialFile.length() + " bytes"); } out = new FileOutputStream(partialFile, partial); long n = copy(in, out); LOG.info("Downloaded " + n + " bytes to " + partialFile); out.flush(); out.close(); if (isCancelled()) { throw new Exception("Download of '" + song + "' was cancelled"); } downloadAndSaveCoverArt(musicService); if (save) { Util.atomicCopy(partialFile, saveFile); mediaStoreService.saveInMediaStore(DownloadFile.this); } else { Util.atomicCopy(partialFile, completeFile); } } catch (Exception x) { Util.close(out); Util.delete(completeFile); Util.delete(saveFile); if (!isCancelled()) { failed = true; LOG.warn("Failed to download '" + song + "'.", x); } } finally { Util.close(in); Util.close(out); if (wakeLock != null) { wakeLock.release(); LOG.info("Released wake lock " + wakeLock); } if (wifiLock != null) { wifiLock.release(); LOG.info("Released wifi lock " + wifiLock); } new CacheCleaner(context, DownloadServiceImpl.getInstance()).clean(); } } @Override public String toString() { return "DownloadTask (" + song + ")"; } private void downloadAndSaveCoverArt(MusicService musicService) throws Exception { try { if (song.getCoverArt() != null) { DisplayMetrics metrics = context.getResources().getDisplayMetrics(); int size = Math.min(metrics.widthPixels, metrics.heightPixels); musicService.getCoverArt(context, song, size, true, null); } } catch (Exception x) { LOG.error("Failed to get cover art.", x); } } private long copy(final InputStream in, OutputStream out) throws IOException, InterruptedException { // Start a thread that will close the input stream if the task is // cancelled, thus causing the copy() method to return. new Thread() { @Override public void run() { while (true) { Util.sleepQuietly(3000L); if (isCancelled()) { Util.close(in); return; } if (!isRunning()) { return; } } } }.start(); byte[] buffer = new byte[1024 * 16]; long count = 0; int n; long lastLog = System.currentTimeMillis(); while (!isCancelled() && (n = in.read(buffer)) != -1) { out.write(buffer, 0, n); count += n; long now = System.currentTimeMillis(); if (now - lastLog > 3000L) { // Only every so often. LOG.info("Downloaded " + Util.formatBytes(count) + " of " + song); lastLog = now; } } return count; } } }