1 /* 2 * Copyright (C) 2011 The Android Open Source Project 3 * 4 * Licensed under the Apache License, Version 2.0 (the "License"); 5 * you may not use this file except in compliance with the License. 6 * You may obtain a copy of the License at 7 * 8 * http://www.apache.org/licenses/LICENSE-2.0 9 * 10 * Unless required by applicable law or agreed to in writing, software 11 * distributed under the License is distributed on an "AS IS" BASIS, 12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 13 * See the License for the specific language governing permissions and 14 * limitations under the License. 15 */ 16 17 package com.example.android.apis.content; 18 19 import java.io.FileNotFoundException; 20 import java.io.FileOutputStream; 21 import java.io.IOException; 22 import java.io.InputStream; 23 24 import android.content.ContentProvider; 25 import android.content.ContentValues; 26 import android.content.ContentProvider.PipeDataWriter; 27 import android.content.res.AssetFileDescriptor; 28 import android.database.Cursor; 29 import android.database.MatrixCursor; 30 import android.net.Uri; 31 import android.os.Bundle; 32 import android.os.ParcelFileDescriptor; 33 import android.provider.OpenableColumns; 34 import android.util.Log; 35 36 /** 37 * A very simple content provider that can serve arbitrary asset files from 38 * our .apk. 39 */ 40 public class FileProvider extends ContentProvider 41 implements PipeDataWriter<InputStream> { 42 @Override onCreate()43 public boolean onCreate() { 44 return true; 45 } 46 47 @Override query(Uri uri, String[] projection, String selection, String[] selectionArgs, String sortOrder)48 public Cursor query(Uri uri, String[] projection, String selection, String[] selectionArgs, 49 String sortOrder) { 50 51 // content providers that support open and openAssetFile should support queries for all 52 // android.provider.OpenableColumns. 53 54 int displayNameIndex = -1; 55 int sizeIndex = -1; 56 57 // If projection is null, return all columns. 58 if (projection == null) { 59 projection = new String[] { 60 OpenableColumns.DISPLAY_NAME, 61 OpenableColumns.SIZE}; 62 } 63 64 for (int i = 0; i < projection.length; i++) { 65 if (OpenableColumns.DISPLAY_NAME.equals(projection[i])) { 66 displayNameIndex = i; 67 } 68 if (OpenableColumns.SIZE.equals(projection[i])) { 69 sizeIndex = i; 70 } 71 } 72 73 MatrixCursor cursor = new MatrixCursor(projection); 74 Object[] result = new Object[projection.length]; 75 76 for (int i = 0; i < result.length; i++) { 77 if (i == displayNameIndex) { 78 result[i] = uri.getPath(); 79 } 80 if (i == sizeIndex) { 81 result[i] = null; // Size is unknown, so null, if it was known, it would go here. 82 } 83 } 84 85 cursor.addRow(result); 86 return cursor; 87 } 88 89 @Override insert(Uri uri, ContentValues values)90 public Uri insert(Uri uri, ContentValues values) { 91 // Don't support inserts. 92 return null; 93 } 94 95 @Override delete(Uri uri, String selection, String[] selectionArgs)96 public int delete(Uri uri, String selection, String[] selectionArgs) { 97 // Don't support deletes. 98 return 0; 99 } 100 101 @Override update(Uri uri, ContentValues values, String selection, String[] selectionArgs)102 public int update(Uri uri, ContentValues values, String selection, String[] selectionArgs) { 103 // Don't support updates. 104 return 0; 105 } 106 107 @Override getType(Uri uri)108 public String getType(Uri uri) { 109 // For this sample, assume all files are .apks. 110 return "application/vnd.android.package-archive"; 111 } 112 113 @Override openAssetFile(Uri uri, String mode)114 public AssetFileDescriptor openAssetFile(Uri uri, String mode) throws FileNotFoundException { 115 // Try to open an asset with the given name. 116 try { 117 InputStream is = getContext().getAssets().open(uri.getPath()); 118 // Start a new thread that pipes the stream data back to the caller. 119 return new AssetFileDescriptor( 120 openPipeHelper(uri, null, null, is, this), 0, 121 AssetFileDescriptor.UNKNOWN_LENGTH); 122 } catch (IOException e) { 123 FileNotFoundException fnf = new FileNotFoundException("Unable to open " + uri); 124 throw fnf; 125 } 126 } 127 128 @Override writeDataToPipe(ParcelFileDescriptor output, Uri uri, String mimeType, Bundle opts, InputStream args)129 public void writeDataToPipe(ParcelFileDescriptor output, Uri uri, String mimeType, 130 Bundle opts, InputStream args) { 131 // Transfer data from the asset to the pipe the client is reading. 132 byte[] buffer = new byte[8192]; 133 int n; 134 FileOutputStream fout = new FileOutputStream(output.getFileDescriptor()); 135 try { 136 while ((n=args.read(buffer)) >= 0) { 137 fout.write(buffer, 0, n); 138 } 139 } catch (IOException e) { 140 Log.i("InstallApk", "Failed transferring", e); 141 } finally { 142 try { 143 args.close(); 144 } catch (IOException e) { 145 } 146 try { 147 fout.close(); 148 } catch (IOException e) { 149 } 150 } 151 } 152 } 153