ImageFetcher.java 9.58 KB
Newer Older
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200 201 202 203 204 205 206 207 208 209 210 211 212 213 214 215 216 217 218 219 220 221 222 223 224 225 226 227 228 229 230 231 232 233 234 235 236 237 238 239 240 241 242 243 244 245 246 247 248 249 250 251 252 253 254 255 256 257 258 259 260 261 262 263 264 265 266 267 268 269 270 271 272 273 274 275 276 277 278 279 280 281 282 283 284 285 286 287 288 289 290
/*
 * 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.imagepicker;

import android.content.Context;
import android.graphics.Bitmap;
import android.net.ConnectivityManager;
import android.net.NetworkInfo;
import android.os.Build;
import android.util.Log;

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 DiskLruCache 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);
                } 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();
                        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();
                } 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;
                    }
                } 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()) {
            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) {

        final String key = ImageCache.hashKeyForDisk(data);
        FileDescriptor fileDescriptor = null;
        FileInputStream fileInputStream = null;
        DiskLruCache.Snapshot snapshot;
        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) {

                        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");
        }
    }
}