Java tutorial
/* * Copyright (C) 2012-2013 Dominik Schrmann <dominik@dominikschuermann.de> * * 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, either version 3 of the License, or * (at your option) any later version. * * 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 org.thialfihar.android.apg.ui.adapter; import android.content.Context; import android.support.v4.content.AsyncTaskLoader; import org.spongycastle.openpgp.PGPKeyRing; import org.spongycastle.openpgp.PGPObjectFactory; import org.spongycastle.openpgp.PGPUtil; import org.thialfihar.android.apg.Constants; import org.thialfihar.android.apg.util.InputData; import org.thialfihar.android.apg.util.Log; import org.thialfihar.android.apg.util.PositionAwareInputStream; import java.io.BufferedInputStream; import java.io.InputStream; import java.util.ArrayList; public class ImportKeysListLoader extends AsyncTaskLoader<AsyncTaskResultWrapper<ArrayList<ImportKeysListEntry>>> { public static class FileHasNoContent extends Exception { } public static class NonPgpPartException extends Exception { private int mCount; public NonPgpPartException(int count) { mCount = count; } public int getCount() { return mCount; } } private Context mContext; private InputData mInputData; private ArrayList<ImportKeysListEntry> mData = new ArrayList<ImportKeysListEntry>(); private AsyncTaskResultWrapper<ArrayList<ImportKeysListEntry>> mEntryListWrapper; public ImportKeysListLoader(Context context, InputData inputData) { super(context); mContext = context; mInputData = inputData; } @Override public AsyncTaskResultWrapper<ArrayList<ImportKeysListEntry>> loadInBackground() { mEntryListWrapper = new AsyncTaskResultWrapper<ArrayList<ImportKeysListEntry>>(mData, null); if (mInputData == null) { Log.e(Constants.TAG, "Input data is null!"); return mEntryListWrapper; } generateListOfKeyrings(mInputData); return mEntryListWrapper; } @Override protected void onReset() { super.onReset(); // Ensure the loader is stopped onStopLoading(); } @Override protected void onStartLoading() { forceLoad(); } @Override protected void onStopLoading() { cancelLoad(); } @Override public void deliverResult(AsyncTaskResultWrapper<ArrayList<ImportKeysListEntry>> mData) { super.deliverResult(mData); } /** * Reads all PGPKeyRing objects from input * * @param inputData * @return */ private void generateListOfKeyrings(InputData inputData) { boolean isEmpty = true; int nonPgpCounter = 0; PositionAwareInputStream progressIn = new PositionAwareInputStream(inputData.getInputStream()); // need to have access to the bufferedInput, so we can reuse it for the possible // PGPObject chunks after the first one, e.g. files with several consecutive ASCII // armor blocks BufferedInputStream bufferedInput = new BufferedInputStream(progressIn); try { // read all available blocks... (asc files can contain many blocks with BEGIN END) while (bufferedInput.available() > 0) { isEmpty = false; InputStream in = PGPUtil.getDecoderStream(bufferedInput); PGPObjectFactory objectFactory = new PGPObjectFactory(in); // go through all objects in this block Object obj; while ((obj = objectFactory.nextObject()) != null) { Log.d(Constants.TAG, "Found class: " + obj.getClass()); if (obj instanceof PGPKeyRing) { PGPKeyRing newKeyring = (PGPKeyRing) obj; addToData(newKeyring); } else { Log.e(Constants.TAG, "Object not recognized as PGPKeyRing!", new Exception()); nonPgpCounter++; } } } } catch (Exception e) { Log.e(Constants.TAG, "Exception on parsing key file!", e); mEntryListWrapper = new AsyncTaskResultWrapper<ArrayList<ImportKeysListEntry>>(mData, e); nonPgpCounter = 0; } if (isEmpty) { Log.e(Constants.TAG, "File has no content!", new FileHasNoContent()); mEntryListWrapper = new AsyncTaskResultWrapper<ArrayList<ImportKeysListEntry>>(mData, new FileHasNoContent()); } if (nonPgpCounter > 0) { mEntryListWrapper = new AsyncTaskResultWrapper<ArrayList<ImportKeysListEntry>>(mData, new NonPgpPartException(nonPgpCounter)); } } private void addToData(PGPKeyRing keyring) { ImportKeysListEntry item = new ImportKeysListEntry(keyring); mData.add(item); } }