Java tutorial
/* * SkyTube * Copyright (C) 2017 Ramon Mifsud * * This program 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 (version 3 of the License). * * This program 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 this program. If not, see <http://www.gnu.org/licenses/>. */ package free.rm.skytube.gui.businessobjects.updates; import android.app.ProgressDialog; import android.content.Context; import android.content.Intent; import android.net.Uri; import android.support.v4.content.FileProvider; import android.util.Log; import android.util.Pair; import android.widget.Toast; import java.io.File; import java.io.FileOutputStream; import java.io.FilenameFilter; import java.io.IOException; import java.io.OutputStream; import java.net.URL; import free.rm.skytube.R; import free.rm.skytube.businessobjects.AsyncTaskParallel; import free.rm.skytube.gui.businessobjects.WebStream; /** * This task will download the remote APK file and it will install it for the user (provided that * the user accepts such installation). */ public class UpgradeAppTask extends AsyncTaskParallel<Void, Integer, Pair<File, Throwable>> { private URL apkUrl; private ProgressDialog downloadDialog; /** The directory where the apks are downloaded to. */ private final File apkDir; private final Context context; private final String TAG = UpgradeAppTask.class.getSimpleName(); public UpgradeAppTask(URL apkUrl, Context context) { this.apkUrl = apkUrl; this.context = context; this.apkDir = context.getCacheDir(); } @Override protected void onPreExecute() { // setup the download dialog and display it downloadDialog = new ProgressDialog(context); downloadDialog.setMessage(context.getString(R.string.downloading)); downloadDialog.setProgressStyle(ProgressDialog.STYLE_HORIZONTAL); downloadDialog.setProgress(0); downloadDialog.setMax(100); downloadDialog.setCancelable(false); downloadDialog.setProgressNumberFormat(null); downloadDialog.show(); } @Override protected Pair<File, Throwable> doInBackground(Void... params) { File apkFile; Throwable exception = null; // delete old apk files deleteOldApkFiles(); // try to download the remote APK file try { apkFile = downloadApk(); } catch (Throwable e) { apkFile = null; exception = e; } return new Pair<>(apkFile, exception); } /** * Delete old (previously-downloaded) APK files. */ private void deleteOldApkFiles() { // get all previously downloaded APK files File[] apkFiles = apkDir.listFiles(new FilenameFilter() { public boolean accept(File dir, String filename) { return filename.endsWith(".apk"); } }); // delete the previously downloaded APK files if (apkFiles != null) { for (File apkFile : apkFiles) { if (apkFile.delete()) { Log.i(TAG, "Deleted " + apkFile.getAbsolutePath()); } else { Log.e(TAG, "Cannot delete " + apkFile.getAbsolutePath()); } } } } /** * Download the remote APK file and return an instance of {@link File}. * * @return A {@link File} instance of the downloaded APK. * @throws IOException */ private File downloadApk() throws IOException { WebStream webStream = new WebStream(this.apkUrl); File apkFile = File.createTempFile("skytube-upgrade", ".apk", apkDir); OutputStream out; // set the APK file to readable to every user so that this file can be read by Android's // package manager program apkFile.setReadable(true /*set file to readable*/, false /*set readable to every user on the system*/); out = new FileOutputStream(apkFile); // download the file by transferring bytes from in to out byte[] buf = new byte[1024]; int totalBytesRead = 0; for (int bytesRead; (bytesRead = webStream.getStream().read(buf)) > 0;) { out.write(buf, 0, bytesRead); // update the progressbar of the downloadDialog totalBytesRead += bytesRead; publishProgress(totalBytesRead, webStream.getStreamSize()); } // close the streams webStream.getStream().close(); out.close(); return apkFile; } @Override protected void onProgressUpdate(Integer... values) { float totalBytesRead = values[0]; float fileSize = values[1]; float percentageDownloaded = (totalBytesRead / fileSize) * 100f; downloadDialog.setProgress((int) percentageDownloaded); } @Override protected void onPostExecute(Pair<File, Throwable> out) { File apkFile = out.first; Throwable exception = out.second; // hide the download dialog downloadDialog.dismiss(); if (exception != null) { Log.e(TAG, "Unable to upgrade app", exception); Toast.makeText(context, R.string.update_failure, Toast.LENGTH_LONG).show(); } else { displayUpgradeAppDialog(apkFile); } } /** * Ask the user whether he wants to install the latest SkyTube's APK file. * * @param apkFile APK file to install. */ private void displayUpgradeAppDialog(File apkFile) { Uri apkFileURI = (android.os.Build.VERSION.SDK_INT >= 24) ? FileProvider.getUriForFile(context, context.getApplicationContext().getPackageName() + ".provider", apkFile) // we now need to call FileProvider.getUriForFile() due to security changes in Android 7.0+ : Uri.fromFile(apkFile); Intent intent = new Intent(Intent.ACTION_VIEW); intent.setDataAndType(apkFileURI, "application/vnd.android.package-archive"); intent.setFlags(Intent.FLAG_ACTIVITY_NEW_TASK /* asks the user to open the newly updated app */ | Intent.FLAG_GRANT_READ_URI_PERMISSION /* to avoid a crash due to security changes in Android 7.0+ */); context.startActivity(intent); } }