android - NoSuchMethodError 在 Android 中使用 LruCache

Question

我在使用从 Android 中的 LruCache 继承的自定义类时遇到错误。它应该下载图像并缓存它们；昨天，它工作正常，但今天早上我遇到了这个问题。

这是类的代码:

public class LruMemoryCache extends LruCache<String, Bitmap> {
    private final Context context;
    private static LruMemoryCache instance;

    private LruMemoryCache(Context context) {
//      super(1024 * 1024 * (((ActivityManager) context.getSystemService(Context.ACTIVITY_SERVICE)).getMemoryClass()) / 8);
        super(5 * 1024 * 1024);
        this.context = context;
    }

    public static synchronized LruMemoryCache getInstance(Context context) {
        if (instance == null) {
            instance = new LruMemoryCache(context);

        }
        return instance;
    }

    @Override
    protected int sizeOf(String key, Bitmap value) {
        return value.getByteCount();
    }

    public void loadBitmap(String url, ImageView imageView) {
        final String imageKey = url;
        final Bitmap bitmap = get(imageKey);
        if (bitmap != null) {
            imageView.setImageBitmap(bitmap);
        } else {
            BitmapWorkerTask task = new BitmapWorkerTask(imageView);
            task.execute(url);
        }
    }

    class BitmapWorkerTask extends AsyncTask<String, Void, Bitmap> {
        Bitmap myBitmap;
        ImageView mImageView;

        public BitmapWorkerTask(ImageView imageView) {
            mImageView = imageView;
        }

        @Override
        protected Bitmap doInBackground(String... params) {
            try {
                URL url = new URL("http://www.google.com/logos/classicplus.png");
                HttpURLConnection connection = (HttpURLConnection) url.openConnection();
                connection.setDoInput(true);
                connection.connect();
                InputStream input = connection.getInputStream();
                myBitmap = BitmapFactory.decodeStream(input);
            } catch (IOException e) {
                e.printStackTrace();
            }

            put(params[0], myBitmap);
            return myBitmap;
        }

        @Override
        protected void onPostExecute(Bitmap result) {
            super.onPostExecute(result);
            mImageView.setImageBitmap(result);
        }
    }
}

这是来自 LogCat 的错误:

05-15 08:02:08.639: E/AndroidRuntime(12818): FATAL EXCEPTION: AsyncTask #2
05-15 08:02:08.639: E/AndroidRuntime(12818): java.lang.RuntimeException: An error occured while executing doInBackground()
05-15 08:02:08.639: E/AndroidRuntime(12818):    at android.os.AsyncTask$3.done(AsyncTask.java:200)
05-15 08:02:08.639: E/AndroidRuntime(12818):    at java.util.concurrent.FutureTask$Sync.innerSetException(FutureTask.java:274)
05-15 08:02:08.639: E/AndroidRuntime(12818):    at java.util.concurrent.FutureTask.setException(FutureTask.java:125)
05-15 08:02:08.639: E/AndroidRuntime(12818):    at java.util.concurrent.FutureTask$Sync.innerRun(FutureTask.java:308)
05-15 08:02:08.639: E/AndroidRuntime(12818):    at java.util.concurrent.FutureTask.run(FutureTask.java:138)
05-15 08:02:08.639: E/AndroidRuntime(12818):    at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1088)
05-15 08:02:08.639: E/AndroidRuntime(12818):    at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:581)
05-15 08:02:08.639: E/AndroidRuntime(12818):    at java.lang.Thread.run(Thread.java:1019)
05-15 08:02:08.639: E/AndroidRuntime(12818): Caused by: java.lang.NoSuchMethodError: getByteCount
05-15 08:02:08.639: E/AndroidRuntime(12818):    at com.xs2theworld.sundio.caching.LruMemoryCache.sizeOf(LruMemoryCache.java:36)
05-15 08:02:08.639: E/AndroidRuntime(12818):    at com.xs2theworld.sundio.caching.LruMemoryCache.sizeOf(LruMemoryCache.java:1)
05-15 08:02:08.639: E/AndroidRuntime(12818):    at android.support.v4.util.LruCache.safeSizeOf(LruCache.java:230)
05-15 08:02:08.639: E/AndroidRuntime(12818):    at android.support.v4.util.LruCache.put(LruCache.java:123)
05-15 08:02:08.639: E/AndroidRuntime(12818):    at com.xs2theworld.sundio.caching.LruMemoryCache$BitmapWorkerTask.doInBackground(LruMemoryCache.java:72)
05-15 08:02:08.639: E/AndroidRuntime(12818):    at com.xs2theworld.sundio.caching.LruMemoryCache$BitmapWorkerTask.doInBackground(LruMemoryCache.java:1)
05-15 08:02:08.639: E/AndroidRuntime(12818):    at android.os.AsyncTask$2.call(AsyncTask.java:185)
05-15 08:02:08.639: E/AndroidRuntime(12818):    at java.util.concurrent.FutureTask$Sync.innerRun(FutureTask.java:306)
05-15 08:02:08.639: E/AndroidRuntime(12818):    ... 4 more

知道为什么会这样吗？

非常感谢大家。

编辑:我刚刚意识到这个错误不会发生在 Google Galaxy Nexus S 手机上，但它会发生在 Samsun Galaxy 上。有人知道为什么吗？

Answer 1

问题是由于:

@Override
    protected int sizeOf(String key, Bitmap value) {
        return value.getByteCount();
    }

getByteCount() 方法只能与 API >= 12 一起使用，而 Samsung Galaxy 使用 API 10。

解决方法:

@Override
    protected int sizeOf(String key, Bitmap value) {
        if (Integer.valueOf(android.os.Build.VERSION.SDK_INT) >= 12)
            return value.getByteCount();
        else
            return (value.getRowBytes() * value.getHeight());
    }