Java tutorial
/* * Copyright (C) 2014 Vlad Mihalachi * * This file is part of Turbo Editor. * * Turbo Editor 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. * * Turbo Editor 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 sharedcode.turboeditor.util; import android.annotation.SuppressLint; import android.content.ContentUris; import android.content.Context; import android.database.Cursor; import android.graphics.Bitmap; import android.graphics.BitmapFactory; import android.net.Uri; import android.os.Build; import android.os.Environment; import android.provider.DocumentsContract; import android.provider.MediaStore; import org.apache.commons.io.FilenameUtils; import java.io.File; import java.io.FileInputStream; import java.io.IOException; public class AccessStorageApi { public static Bitmap loadPrescaledBitmap(String filename) throws IOException { // Facebook image size final int IMAGE_MAX_SIZE = 630; File file = null; FileInputStream fis; BitmapFactory.Options opts; int resizeScale; Bitmap bmp; file = new File(filename); // This bit determines only the width/height of the bitmap without loading the contents opts = new BitmapFactory.Options(); opts.inJustDecodeBounds = true; fis = new FileInputStream(file); BitmapFactory.decodeStream(fis, null, opts); fis.close(); // Find the correct scale value. It should be a power of 2 resizeScale = 1; if (opts.outHeight > IMAGE_MAX_SIZE || opts.outWidth > IMAGE_MAX_SIZE) { resizeScale = (int) Math.pow(2, (int) Math.round( Math.log(IMAGE_MAX_SIZE / (double) Math.max(opts.outHeight, opts.outWidth)) / Math.log(0.5))); } // Load pre-scaled bitmap opts = new BitmapFactory.Options(); opts.inSampleSize = resizeScale; fis = new FileInputStream(file); bmp = BitmapFactory.decodeStream(fis, null, opts); fis.close(); return bmp; } /** * Get a file path from a Uri. This will get the the path for Storage Access * Framework Documents, as well as the _data field for the MediaStore and * other file-based ContentProviders. * * @param context The context. * @param uri The Uri to query. * @author paulburke */ @SuppressLint("NewApi") public static String getPath(final Context context, final Uri uri) { String path = ""; if (uri == null || uri.equals(Uri.EMPTY)) return ""; try { final boolean isKitKat = Build.VERSION.SDK_INT >= Build.VERSION_CODES.KITKAT; // DocumentProvider if (isKitKat && DocumentsContract.isDocumentUri(context, uri)) { if (isTurboDocument(uri)) { final String docId = DocumentsContract.getDocumentId(uri); final String[] split = docId.split(":"); path = "/" + split[1]; } // ExternalStorageProvider else if (isExternalStorageDocument(uri)) { final String docId = DocumentsContract.getDocumentId(uri); final String[] split = docId.split(":"); final String type = split[0]; if ("primary".equalsIgnoreCase(type)) { path = Environment.getExternalStorageDirectory() + "/" + split[1]; } // TODO handle non-primary volumes } // DownloadsProvider else if (isDownloadsDocument(uri)) { final String id = DocumentsContract.getDocumentId(uri); final Uri contentUri = ContentUris .withAppendedId(Uri.parse("content://downloads/public_downloads"), Long.valueOf(id)); path = getDataColumn(context, contentUri, null, null); } // MediaProvider else if (isMediaDocument(uri)) { final String docId = DocumentsContract.getDocumentId(uri); final String[] split = docId.split(":"); final String type = split[0]; Uri contentUri = null; if ("image".equals(type)) { contentUri = MediaStore.Images.Media.EXTERNAL_CONTENT_URI; } else if ("video".equals(type)) { contentUri = MediaStore.Video.Media.EXTERNAL_CONTENT_URI; } else if ("audio".equals(type)) { contentUri = MediaStore.Audio.Media.EXTERNAL_CONTENT_URI; } final String selection = "_id=?"; final String[] selectionArgs = new String[] { split[1] }; path = getDataColumn(context, contentUri, selection, selectionArgs); } } // MediaStore (and general) else if ("content".equalsIgnoreCase(uri.getScheme())) { path = getDataColumn(context, uri, null, null); } // File else if ("file".equalsIgnoreCase(uri.getScheme())) { path = uri.getPath(); } } catch (Exception ex) { return ""; } return path; } public static String getName(Context context, Uri uri) { if (uri == null || uri.equals(Uri.EMPTY)) return ""; String fileName = ""; try { String scheme = uri.getScheme(); if (scheme.equals("file")) { fileName = uri.getLastPathSegment(); } else if (scheme.equals("content")) { String[] proj = { MediaStore.Images.Media.DISPLAY_NAME }; Cursor cursor = context.getContentResolver().query(uri, proj, null, null, null); if (cursor != null && cursor.getCount() != 0) { int columnIndex = cursor.getColumnIndexOrThrow(MediaStore.Images.Media.DISPLAY_NAME); cursor.moveToFirst(); fileName = cursor.getString(columnIndex); } if (cursor != null) { cursor.close(); } } } catch (Exception ex) { return ""; } return fileName; } public static String getExtension(Context context, Uri uri) { return FilenameUtils.getExtension(getName(context, uri)); } /** * Get the value of the data column for this Uri. This is useful for * MediaStore Uris, and other file-based ContentProviders. * * @param context The context. * @param uri The Uri to query. * @param selection (Optional) Filter used in the query. * @param selectionArgs (Optional) Selection arguments used in the query. * @return The value of the _data column, which is typically a file path. */ public static String getDataColumn(Context context, Uri uri, String selection, String[] selectionArgs) { Cursor cursor = null; final String column = "_data"; final String[] projection = { column }; try { cursor = context.getContentResolver().query(uri, projection, selection, selectionArgs, null); if (cursor != null && cursor.moveToFirst()) { final int column_index = cursor.getColumnIndexOrThrow(column); return cursor.getString(column_index); } } finally { if (cursor != null) cursor.close(); } return null; } /** * @param uri The Uri to check. * @return Whether the Uri authority is ExternalStorageProvider. */ public static boolean isExternalStorageDocument(Uri uri) { return "com.android.externalstorage.documents".equals(uri.getAuthority()); } /** * @param uri The Uri to check. * @return Whether the Uri authority is DownloadsProvider. */ public static boolean isDownloadsDocument(Uri uri) { return "com.android.providers.downloads.documents".equals(uri.getAuthority()); } /** * @param uri The Uri to check. * @return Whether the Uri authority is MediaProvider. */ public static boolean isMediaDocument(Uri uri) { return "com.android.providers.media.documents".equals(uri.getAuthority()); } /** * @param uri The Uri to check. * @return Whether the Uri authority is Turbo Storage. */ public static boolean isTurboDocument(Uri uri) { return "sharedcode.turboeditor.util.documents".equals(uri.getAuthority()); } }