Java tutorial
/* Licensed to the Apache Software Foundation (ASF) under one or more contributor license agreements. See the NOTICE file distributed with this work for additional information regarding copyright ownership. The ASF licenses this file to you under the Apache License, Version 2.0 (the "License"); you may not use this file except in compliance with the License. You may obtain a copy of the License at http://www.apache.org/licenses/LICENSE-2.0 Unless required by applicable law or agreed to in writing, software distributed under the License is distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the License for the specific language governing permissions and limitations under the License. */ package com.remobile.file; import java.io.File; import java.io.FileNotFoundException; import java.io.IOException; import java.io.OutputStream; import com.remobile.cordova.CordovaResourceApi; import org.json.JSONArray; import org.json.JSONException; import org.json.JSONObject; import android.content.ContentResolver; import android.content.Context; import android.database.Cursor; import android.net.Uri; import android.provider.MediaStore; import android.provider.OpenableColumns; public class ContentFilesystem extends Filesystem { private final Context context; public ContentFilesystem(Context context, CordovaResourceApi resourceApi) { super(Uri.parse("content://"), "content", resourceApi); this.context = context; } @Override public Uri toNativeUri(LocalFilesystemURL inputURL) { String authorityAndPath = inputURL.uri.getEncodedPath().substring(this.name.length() + 2); if (authorityAndPath.length() < 2) { return null; } String ret = "content://" + authorityAndPath; String query = inputURL.uri.getEncodedQuery(); if (query != null) { ret += '?' + query; } String frag = inputURL.uri.getEncodedFragment(); if (frag != null) { ret += '#' + frag; } return Uri.parse(ret); } @Override public LocalFilesystemURL toLocalUri(Uri inputURL) { if (!"content".equals(inputURL.getScheme())) { return null; } String subPath = inputURL.getEncodedPath(); if (subPath.length() > 0) { subPath = subPath.substring(1); } Uri.Builder b = new Uri.Builder().scheme(LocalFilesystemURL.FILESYSTEM_PROTOCOL).authority("localhost") .path(name).appendPath(inputURL.getAuthority()); if (subPath.length() > 0) { b.appendEncodedPath(subPath); } Uri localUri = b.encodedQuery(inputURL.getEncodedQuery()).encodedFragment(inputURL.getEncodedFragment()) .build(); return LocalFilesystemURL.parse(localUri); } @Override public JSONObject getFileForLocalURL(LocalFilesystemURL inputURL, String fileName, JSONObject options, boolean directory) throws IOException, TypeMismatchException, JSONException { throw new UnsupportedOperationException( "getFile() not supported for content:. Use resolveLocalFileSystemURL instead."); } @Override public boolean removeFileAtLocalURL(LocalFilesystemURL inputURL) throws NoModificationAllowedException { Uri contentUri = toNativeUri(inputURL); try { context.getContentResolver().delete(contentUri, null, null); } catch (UnsupportedOperationException t) { // Was seeing this on the File mobile-spec tests on 4.0.3 x86 emulator. // The ContentResolver applies only when the file was registered in the // first case, which is generally only the case with images. throw new NoModificationAllowedException("Deleting not supported for content uri: " + contentUri); } return true; } @Override public boolean recursiveRemoveFileAtLocalURL(LocalFilesystemURL inputURL) throws NoModificationAllowedException { throw new NoModificationAllowedException("Cannot remove content url"); } @Override public LocalFilesystemURL[] listChildren(LocalFilesystemURL inputURL) throws FileNotFoundException { throw new UnsupportedOperationException( "readEntriesAtLocalURL() not supported for content:. Use resolveLocalFileSystemURL instead."); } @Override public JSONObject getFileMetadataForLocalURL(LocalFilesystemURL inputURL) throws FileNotFoundException { long size = -1; long lastModified = 0; Uri nativeUri = toNativeUri(inputURL); String mimeType = resourceApi.getMimeType(nativeUri); Cursor cursor = openCursorForURL(nativeUri); try { if (cursor != null && cursor.moveToFirst()) { size = resourceSizeForCursor(cursor); lastModified = lastModifiedDateForCursor(cursor); } else { // Some content providers don't support cursors at all! CordovaResourceApi.OpenForReadResult offr = resourceApi.openForRead(nativeUri); size = offr.length; } } catch (IOException e) { throw new FileNotFoundException(); } finally { if (cursor != null) cursor.close(); } JSONObject metadata = new JSONObject(); try { metadata.put("size", size); metadata.put("type", mimeType); metadata.put("name", name); metadata.put("fullPath", inputURL.path); metadata.put("lastModifiedDate", lastModified); } catch (JSONException e) { return null; } return metadata; } @Override public long writeToFileAtURL(LocalFilesystemURL inputURL, String data, int offset, boolean isBinary) throws NoModificationAllowedException { throw new NoModificationAllowedException("Couldn't write to file given its content URI"); } @Override public long truncateFileAtURL(LocalFilesystemURL inputURL, long size) throws NoModificationAllowedException { throw new NoModificationAllowedException("Couldn't truncate file given its content URI"); } protected Cursor openCursorForURL(Uri nativeUri) { ContentResolver contentResolver = context.getContentResolver(); try { return contentResolver.query(nativeUri, null, null, null, null); } catch (UnsupportedOperationException e) { return null; } } private Long resourceSizeForCursor(Cursor cursor) { int columnIndex = cursor.getColumnIndex(OpenableColumns.SIZE); if (columnIndex != -1) { String sizeStr = cursor.getString(columnIndex); if (sizeStr != null) { return Long.parseLong(sizeStr); } } return null; } protected Long lastModifiedDateForCursor(Cursor cursor) { final String[] LOCAL_FILE_PROJECTION = { MediaStore.MediaColumns.DATE_MODIFIED }; int columnIndex = cursor.getColumnIndex(LOCAL_FILE_PROJECTION[0]); if (columnIndex != -1) { String dateStr = cursor.getString(columnIndex); if (dateStr != null) { return Long.parseLong(dateStr); } } return null; } @Override public String filesystemPathForURL(LocalFilesystemURL url) { File f = resourceApi.mapUriToFile(toNativeUri(url)); return f == null ? null : f.getAbsolutePath(); } @Override public LocalFilesystemURL URLforFilesystemPath(String path) { // Returns null as we don't support reverse mapping back to content:// URLs return null; } @Override public boolean canRemoveFileAtLocalURL(LocalFilesystemURL inputURL) { return true; } }