1 /* 2 * Copyright (C) 2012 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.displayingbitmaps.util; 18 19 import android.content.Context; 20 import android.graphics.Bitmap; 21 import android.net.ConnectivityManager; 22 import android.net.NetworkInfo; 23 import android.os.Build; 24 import android.widget.Toast; 25 26 import com.example.android.common.logger.Log; 27 import com.example.android.displayingbitmaps.BuildConfig; 28 import com.example.android.displayingbitmaps.R; 29 30 import java.io.BufferedInputStream; 31 import java.io.BufferedOutputStream; 32 import java.io.File; 33 import java.io.FileDescriptor; 34 import java.io.FileInputStream; 35 import java.io.IOException; 36 import java.io.OutputStream; 37 import java.net.HttpURLConnection; 38 import java.net.URL; 39 40 /** 41 * A simple subclass of {@link ImageResizer} that fetches and resizes images fetched from a URL. 42 */ 43 public class ImageFetcher extends ImageResizer { 44 private static final String TAG = "ImageFetcher"; 45 private static final int HTTP_CACHE_SIZE = 10 * 1024 * 1024; // 10MB 46 private static final String HTTP_CACHE_DIR = "http"; 47 private static final int IO_BUFFER_SIZE = 8 * 1024; 48 49 private Dis kLruCache mHttpDiskCache; 50 private File mHttpCacheDir; 51 private boolean mHttpDiskCacheStarting = true; 52 private final Object mHttpDiskCacheLock = new Object(); 53 private static final int DISK_CACHE_INDEX = 0; 54 55 /** 56 * Initialize providing a target image width and height for the processing images. 57 * 58 * @param context 59 * @param imageWidth 60 * @param imageHeight 61 */ 62 public ImageFetcher(Context context, int imageWidth, int imageHeight) { 63 super(context, imageWidth, imageHeight); 64 init(context); 65 } 66 67 /** 68 * Initialize providing a single target image size (used for both width and height); 69 * 70 * @param context 71 * @param imageSize 72 */ 73 public ImageFetcher(Context context, int imageSize) { 74 super(context, imageSize); 75 init(context); 76 } 77 78 private void init(Context context) { 79 checkConnection(context); 80 mHttpCacheDir = ImageCache.getDiskCacheDir(context, HTTP_CACHE_DIR); 81 } 82 83 @Override 84 protected void initDiskCacheInternal() { 85 super.initDiskCacheInternal(); 86 initHttpDiskCache(); 87 } 88 89 private void initHttpDiskCache() { 90 if (!mHttpCacheDir.exists()) { 91 mHttpCacheDir.mkdirs(); 92 } 93 synchronized (mHttpDiskCacheLock) { 94 if (ImageCache.getUsableSpace(mHttpCacheDir) > HTTP_CACHE_SIZE) { 95 try { 96 mHttpDiskCache = DiskLruCache.open(mHttpCacheDir, 1, 1, HTTP_CACHE_SIZE); 97 if (BuildConfig.DEBUG) { 98 Log.d(TAG, "HTTP cache initialized"); 99 } 100 } catch (IOException e) { 101 mHttpDiskCache = null; 102 } 103 } 104 mHttpDiskCacheStarting = false; 105 mHttpDiskCacheLock.notifyAll(); 106 } 107 } 108 109 @Override 110 protected void clearCacheInternal() { 111 super.clearCacheInternal(); 112 synchronized (mHttpDiskCacheLock) { 113 if (mHttpDiskCache != null && !mHttpDiskCache.isClosed()) { 114 try { 115 mHttpDiskCache.delete(); 116 if (BuildConfig.DEBUG) { 117 Log.d(TAG, "HTTP cache cleared"); 118 } 119 } catch (IOException e) { 120 Log.e(TAG, "clearCacheInternal - " + e); 121 } 122 mHttpDiskCache = null; 123 mHttpDiskCacheStarting = true; 124 initHttpDiskCache(); 125 } 126 } 127 } 128 129 @Override 130 protected void flushCacheInternal() { 131 super.flushCacheInternal(); 132 synchronized (mHttpDiskCacheLock) { 133 if (mHttpDiskCache != null) { 134 try { 135 mHttpDiskCache.flush(); 136 if (BuildConfig.DEBUG) { 137 Log.d(TAG, "HTTP cache flushed"); 138 } 139 } catch (IOException e) { 140 Log.e(TAG, "flush - " + e); 141 } 142 } 143 } 144 } 145 146 @Override 147 protected void closeCacheInternal() { 148 super.closeCacheInternal(); 149 synchronized (mHttpDiskCacheLock) { 150 if (mHttpDiskCache != null) { 151 try { 152 if (!mHttpDiskCache.isClosed()) { 153 mHttpDiskCache.close(); 154 mHttpDiskCache = null; 155 if (BuildConfig.DEBUG) { 156 Log.d(TAG, "HTTP cache closed"); 157 } 158 } 159 } catch (IOException e) { 160 Log.e(TAG, "closeCacheInternal - " + e); 161 } 162 } 163 } 164 } 165 166 /** 167 * Simple network connection check. 168 * 169 * @param context 170 */ 171 private void checkConnection(Context context) { 172 final ConnectivityManager cm = 173 (ConnectivityManager) context.getSystemService(Context.CONNECTIVITY_SERVICE); 174 final NetworkInfo networkInfo = cm.getActiveNetworkInfo(); 175 if (networkInfo == null || !networkInfo.isConnectedOrConnecting()) { 176 Toast.makeText(context, R.string.no_network_connection_toast, Toast.LENGTH_LONG).show(); 177 Log.e(TAG, "checkConnection - no connection found"); 178 } 179 } 180 181 /** 182 * The main process method, which will be called by the ImageWorker in the AsyncTask background 183 * thread. 184 * 185 * @param data The data to load the bitmap, in this case, a regular http URL 186 * @return The downloaded and resized bitmap 187 */ 188 private Bitmap processBitmap(String data) { 189 if (BuildConfig.DEBUG) { 190 Log.d(TAG, "processBitmap - " + data); 191 } 192 193 final String key = ImageCache.hashKeyForDisk(data); 194 FileDescriptor fileDescriptor = null; 195 FileInputStream fileInputStream = null; 196 DiskLruCache.Snapshot snapshot; 197 synchronized (mHttpDiskCacheLock) { 198 // Wait for disk cache to initialize 199 while (mHttpDiskCacheStarting) { 200 try { 201 mHttpDiskCacheLock.wait(); 202 } catch (InterruptedException e) {} 203 } 204 205 if (mHttpDiskCache != null) { 206 try { 207 snapshot = mHttpDiskCache.get(key); 208 if (snapshot == null) { 209 if (BuildConfig.DEBUG) { 210 Log.d(TAG, "processBitmap, not found in http cache, downloading..."); 211 } 212 DiskLruCache.Editor editor = mHttpDiskCache.edit(key); 213 if (editor != null) { 214 if (downloadUrlToStream(data, 215 editor.newOutputStream(DISK_CACHE_INDEX))) { 216 editor.commit(); 217 } else { 218 editor.abort(); 219 } 220 } 221 snapshot = mHttpDiskCache.get(key); 222 } 223 if (snapshot != null) { 224 fileInputStream = 225 (FileInputStream) snapshot.getInputStream(DISK_CACHE_INDEX); 226 fileDescriptor = fileInputStream.getFD(); 227 } 228 } catch (IOException e) { 229 Log.e(TAG, "processBitmap - " + e); 230 } catch (IllegalStateException e) { 231 Log.e(TAG, "processBitmap - " + e); 232 } finally { 233 if (fileDescriptor == null && fileInputStream != null) { 234 try { 235 fileInputStream.close(); 236 } catch (IOException e) {} 237 } 238 } 239 } 240 } 241 242 Bitmap bitmap = null; 243 if (fileDescriptor != null) { 244 bitmap = decodeSampledBitmapFromDescriptor(fileDescriptor, mImageWidth, 245 mImageHeight, getImageCache()); 246 } 247 if (fileInputStream != null) { 248 try { 249 fileInputStream.close(); 250 } catch (IOException e) {} 251 } 252 return bitmap; 253 } 254 255 @Override 256 protected Bitmap processBitmap(Object data) { 257 return processBitmap(String.valueOf(data)); 258 } 259 260 /** 261 * Download a bitmap from a URL and write the content to an output stream. 262 * 263 * @param urlString The URL to fetch 264 * @return true if successful, false otherwise 265 */ 266 public boolean downloadUrlToStream(String urlString, OutputStream outputStream) { 267 disableConnectionReuseIfNecessary(); 268 HttpURLConnection urlConnection = null; 269 BufferedOutputStream out = null; 270 BufferedInputStream in = null; 271 272 try { 273 final URL url = new URL(urlString); 274 urlConnection = (HttpURLConnection) url.openConnection(); 275 in = new BufferedInputStream(urlConnection.getInputStream(), IO_BUFFER_SIZE); 276 out = new BufferedOutputStream(outputStream, IO_BUFFER_SIZE); 277 278 int b; 279 while ((b = in.read()) != -1) { 280 out.write(b); 281 } 282 return true; 283 } catch (final IOException e) { 284 Log.e(TAG, "Error in downloadBitmap - " + e); 285 } finally { 286 if (urlConnection != null) { 287 urlConnection.disconnect(); 288 } 289 try { 290 if (out != null) { 291 out.close(); 292 } 293 if (in != null) { 294 in.close(); 295 } 296 } catch (final IOException e) {} 297 } 298 return false; 299 } 300 301 /** 302 * Workaround for bug pre-Froyo, see here for more info: 303 * http://android-developers.blogspot.com/2011/09/androids-http-clients.html 304 */ 305 public static void disableConnectionReuseIfNecessary() { 306 // HTTP connection reuse which was buggy pre-froyo 307 if (Build.VERSION.SDK_INT < Build.VERSION_CODES.FROYO) { 308 System.setProperty("http.keepAlive", "false"); 309 } 310 } 311 }