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/*
* Copyright (C) 2012 The Android Open Source Project
*
* Licensed 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.example.android.displayingbitmaps.util;
import android.content.Context;
import android.graphics.Bitmap;
import android.net.ConnectivityManager;
import android.net.NetworkInfo;
import android.os.Build;
import android.widget.Toast;
import com.example.android.common.logger.Log;
import com.example.android.displayingbitmaps.BuildConfig;
import com.example.android.displayingbitmaps.R;
import java.io.BufferedInputStream;
import java.io.BufferedOutputStream;
import java.io.File;
import java.io.FileDescriptor;
import java.io.FileInputStream;
import java.io.IOException;
import java.io.OutputStream;
import java.net.HttpURLConnection;
import java.net.URL;
/**
* A simple subclass of {@link ImageResizer} that fetches and resizes images fetched from a URL.
*/
public class ImageFetcher extends ImageResizer {
private static final String TAG = "ImageFetcher";
private static final int HTTP_CACHE_SIZE = 10 * 1024 * 1024; // 10MB
private static final String HTTP_CACHE_DIR = "http";
private static final int IO_BUFFER_SIZE = 8 * 1024;
private Dis
kLruCache mHttpDiskCache;
private File mHttpCacheDir;
private boolean mHttpDiskCacheStarting = true;
private final Object mHttpDiskCacheLock = new Object();
private static final int DISK_CACHE_INDEX = 0;
/**
* Initialize providing a target image width and height for the processing images.
*
* @param context
* @param imageWidth
* @param imageHeight
*/
public ImageFetcher(Context context, int imageWidth, int imageHeight) {
super(context, imageWidth, imageHeight);
init(context);
}
/**
* Initialize providing a single target image size (used for both width and height);
*
* @param context
* @param imageSize
*/
public ImageFetcher(Context context, int imageSize) {
super(context, imageSize);
init(context);
}
private void init(Context context) {
checkConnection(context);
mHttpCacheDir = ImageCache.getDiskCacheDir(context, HTTP_CACHE_DIR);
}
@Override
protected void initDiskCacheInternal() {
super.initDiskCacheInternal();
initHttpDiskCache();
}
private void initHttpDiskCache() {
if (!mHttpCacheDir.exists()) {
mHttpCacheDir.mkdirs();
}
synchronized (mHttpDiskCacheLock) {
if (ImageCache.getUsableSpace(mHttpCacheDir) > HTTP_CACHE_SIZE) {
try {
mHttpDiskCache = DiskLruCache.open(mHttpCacheDir, 1, 1, HTTP_CACHE_SIZE);
if (BuildConfig.DEBUG) {
Log.d(TAG, "HTTP cache initialized");
}
} catch (IOException e) {
mHttpDiskCache = null;
}
}
mHttpDiskCacheStarting = false;
mHttpDiskCacheLock.notifyAll();
}
}
@Override
protected void clearCacheInternal() {
super.clearCacheInternal();
synchronized (mHttpDiskCacheLock) {
if (mHttpDiskCache != null && !mHttpDiskCache.isClosed()) {
try {
mHttpDiskCache.delete();
if (BuildConfig.DEBUG) {
Log.d(TAG, "HTTP cache cleared");
}
} catch (IOException e) {
Log.e(TAG, "clearCacheInternal - " + e);
}
mHttpDiskCache = null;
mHttpDiskCacheStarting = true;
initHttpDiskCache();
}
}
}
@Override
protected void flushCacheInternal() {
super.flushCacheInternal();
synchronized (mHttpDiskCacheLock) {
if (mHttpDiskCache != null) {
try {
mHttpDiskCache.flush();
if (BuildConfig.DEBUG) {
Log.d(TAG, "HTTP cache flushed");
}
} catch (IOException e) {
Log.e(TAG, "flush - " + e);
}
}
}
}
@Override
protected void closeCacheInternal() {
super.closeCacheInternal();
synchronized (mHttpDiskCacheLock) {
if (mHttpDiskCache != null) {
try {
if (!mHttpDiskCache.isClosed()) {
mHttpDiskCache.close();
mHttpDiskCache = null;
if (BuildConfig.DEBUG) {
Log.d(TAG, "HTTP cache closed");
}
}
} catch (IOException e) {
Log.e(TAG, "closeCacheInternal - " + e);
}
}
}
}
/**
* Simple network connection check.
*
* @param context
*/
private void checkConnection(Context context) {
final ConnectivityManager cm =
(ConnectivityManager) context.getSystemService(Context.CONNECTIVITY_SERVICE);
final NetworkInfo networkInfo = cm.getActiveNetworkInfo();
if (networkInfo == null || !networkInfo.isConnectedOrConnecting()) {
Toast.makeText(context, R.string.no_network_connection_toast, Toast.LENGTH_LONG).show();
Log.e(TAG, "checkConnection - no connection found");
}
}
/**
* The main process method, which will be called by the ImageWorker in the AsyncTask background
* thread.
*
* @param data The data to load the bitmap, in this case, a regular http URL
* @return The downloaded and resized bitmap
*/
private Bitmap processBitmap(String data) {
if (BuildConfig.DEBUG) {
Log.d(TAG, "processBitmap - " + data);
}
final String key = ImageCache.hashKeyForDisk(data);
FileDescriptor fileDescriptor = null;
FileInputStream fileInputStream = null;
DiskLruCache.Snapshot snapshot;
197
synchronized (mHttpDiskCacheLock) {
// Wait for disk cache to initialize
while (mHttpDiskCacheStarting) {
try {
mHttpDiskCacheLock.wait();
} catch (InterruptedException e) {}
}
if (mHttpDiskCache != null) {
try {
snapshot = mHttpDiskCache.get(key);
if (snapshot == null) {
if (BuildConfig.DEBUG) {
Log.d(TAG, "processBitmap, not found in http cache, downloading...");
}
DiskLruCache.Editor editor = mHttpDiskCache.edit(key);
if (editor != null) {
if (downloadUrlToStream(data,
editor.newOutputStream(DISK_CACHE_INDEX))) {
editor.commit();
} else {
editor.abort();
}
}
snapshot = mHttpDiskCache.get(key);
}
if (snapshot != null) {
fileInputStream =
(FileInputStream) snapshot.getInputStream(DISK_CACHE_INDEX);
fileDescriptor = fileInputStream.getFD();
}
} catch (IOException e) {
Log.e(TAG, "processBitmap - " + e);
} catch (IllegalStateException e) {
Log.e(TAG, "processBitmap - " + e);
} finally {
if (fileDescriptor == null && fileInputStream != null) {
try {
fileInputStream.close();
} catch (IOException e) {}
}
}
}
}
Bitmap bitmap = null;
if (fileDescriptor != null) {
bitmap = decodeSampledBitmapFromDescriptor(fileDescriptor, mImageWidth,
mImageHeight, getImageCache());
}
if (fileInputStream != null) {
try {
fileInputStream.close();
} catch (IOException e) {}
}
return bitmap;
}
@Override
protected Bitmap processBitmap(Object data) {
return processBitmap(String.valueOf(data));
}
/**
* Download a bitmap from a URL and write the content to an output stream.
*
* @param urlString The URL to fetch
* @return true if successful, false otherwise
*/
public boolean downloadUrlToStream(String urlString, OutputStream outputStream) {
disableConnectionReuseIfNecessary();
HttpURLConnection urlConnection = null;
BufferedOutputStream out = null;
BufferedInputStream in = null;
try {
final URL url = new URL(urlString);
urlConnection = (HttpURLConnection) url.openConnection();
in = new BufferedInputStream(urlConnection.getInputStream(), IO_BUFFER_SIZE);
out = new BufferedOutputStream(outputStream, IO_BUFFER_SIZE);
int b;
while ((b = in.read()) != -1) {
out.write(b);
}
return true;
} catch (final IOException e) {
Log.e(TAG, "Error in downloadBitmap - " + e);
} finally {
if (urlConnection != null) {
urlConnection.disconnect();
}
try {
if (out != null) {
out.close();
}
if (in != null) {
in.close();
}
} catch (final IOException e) {}
}
return false;
}
/**
* Workaround for bug pre-Froyo, see here for more info:
* http://android-developers.blogspot.com/2011/09/androids-http-clients.html
*/
public static void disableConnectionReuseIfNecessary() {
// HTTP connection reuse which was buggy pre-froyo
if (Build.VERSION.SDK_INT < Build.VERSION_CODES.FROYO) {
System.setProperty("http.keepAlive", "false");
}
}
}