无需第三方库即可下载远程映像的最佳方法？

Question

Welcome

I need to download sycnronously (one at time) a lot of small remote images (between 50kb and 100kb) from a server and to store them as PNG in the device. I need to achieve this without third party libraries and I'm using this code but it is too munch slow:

        URL javaUrl = new URL(URLParser.parse(this.url));
        URLConnection connection = javaUrl.openConnection();

        InputStream input = new BufferedInputStream(javaUrl.openStream());
        ByteArrayOutputStream output = new ByteArrayOutputStream();

        byte data[] = new byte[1024];
        long total = 0;
        int count;
        while ((count = input.read(data)) != -1) {
            total += count;
            output.write(data, 0, count);
        }

        // conversion to bitmap
        InputStream in = new ByteArrayInputStream(output.toByteArray());
        Bitmap original = BitmapFactory.decodeStream(in);

        // storing bitmap as PNG file
        FileOutputStream out = new FileOutputStream(filename);
        original.compress(Bitmap.CompressFormat.PNG, 90, out);

        output.flush();
        output.close();
        input.close();
        in.close();
        original.recycle(); 

The problem is that the download is very slow. With very fast WIFI internet in the device (13MB, download speed of 1.4mbytes/s), it is taking 3-4 seconds to download the image in the device, but only 100-200ms to download the image in my PC using google chrome for example.

It is something wrong in my download algorithm? can be improved?

Thanks

Answer 1

You have a totally unnecessary byte array in the middle. BitmapFactory.decodeStream() accepts an InputStream and you get an InputStream from URL.openStream() .

It might not give you the speed boost you're looking for, but it'll at least get rid of a completely useless step in your code.