Java tutorial
/* * Copyright (C) 2012-2014 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.sufficientlysecure.keychain.helper; import android.app.Activity; import android.content.ActivityNotFoundException; import android.content.Context; import android.content.Intent; import android.database.Cursor; import android.net.Uri; import android.os.Environment; import android.support.v4.app.Fragment; import android.widget.Toast; import org.sufficientlysecure.keychain.Constants; import org.sufficientlysecure.keychain.R; import org.sufficientlysecure.keychain.util.Log; public class FileHelper { /** * Checks if external storage is mounted if file is located on external storage * * @param file * @return true if storage is mounted */ public static boolean isStorageMounted(String file) { if (file.startsWith(Environment.getExternalStorageDirectory().getAbsolutePath())) { if (!Environment.getExternalStorageState().equals(Environment.MEDIA_MOUNTED)) { return false; } } return true; } /** * Opens the preferred installed file manager on Android and shows a toast if no manager is * installed. * * @param activity * @param filename default selected file, not supported by all file managers * @param mimeType can be text/plain for example * @param requestCode requestCode used to identify the result coming back from file manager to * onActivityResult() in your activity */ public static void openFile(Activity activity, String filename, String mimeType, int requestCode) { Intent intent = buildFileIntent(filename, mimeType); try { activity.startActivityForResult(intent, requestCode); } catch (ActivityNotFoundException e) { // No compatible file manager was found. Toast.makeText(activity, R.string.no_filemanager_installed, Toast.LENGTH_SHORT).show(); } } public static void openFile(Fragment fragment, String filename, String mimeType, int requestCode) { Intent intent = buildFileIntent(filename, mimeType); try { fragment.startActivityForResult(intent, requestCode); } catch (ActivityNotFoundException e) { // No compatible file manager was found. Toast.makeText(fragment.getActivity(), R.string.no_filemanager_installed, Toast.LENGTH_SHORT).show(); } } private static Intent buildFileIntent(String filename, String mimeType) { Intent intent = new Intent(Intent.ACTION_GET_CONTENT); intent.addCategory(Intent.CATEGORY_OPENABLE); intent.setData(Uri.parse("file://" + filename)); intent.setType(mimeType); return intent; } /** * Get a file path from a Uri. * <p/> * from https://github.com/iPaulPro/aFileChooser/blob/master/aFileChooser/src/com/ipaulpro/ * afilechooser/utils/FileUtils.java * * @param context * @param uri * @return * @author paulburke */ public static String getPath(Context context, Uri uri) { Log.d(Constants.TAG + " File -", "Authority: " + uri.getAuthority() + ", Fragment: " + uri.getFragment() + ", Port: " + uri.getPort() + ", Query: " + uri.getQuery() + ", Scheme: " + uri.getScheme() + ", Host: " + uri.getHost() + ", Segments: " + uri.getPathSegments().toString()); if ("content".equalsIgnoreCase(uri.getScheme())) { String[] projection = { "_data" }; Cursor cursor = context.getContentResolver().query(uri, projection, null, null, null); try { if (cursor != null && cursor.moveToFirst()) { int columnIndex = cursor.getColumnIndexOrThrow("_data"); return cursor.getString(columnIndex); } } catch (Exception e) { // Eat it } finally { if (cursor != null) { cursor.close(); } } } else if ("file".equalsIgnoreCase(uri.getScheme())) { return uri.getPath(); } return null; } }