Can someone please tell me where I’m going wrong with this piece of code? Basically I want the app to download a .png file, display it to the user and also save it to the sd card for future reference. It seems to be all going fine until the while ((len = webstream.read(buffer)) > 0) part; as the debugger doesn’t reach the breakpoint I’ve put in here, and I have a directory of empty .png files. I have the WRITE_EXTERNAL_STORAGE permission declared in my Manifest.
protected class DownloadTask extends AsyncTask<String, Integer, Bitmap> {
@Override
protected Bitmap doInBackground(String... string) {
Bitmap d = null;
try {
DefaultHttpClient dhc = new DefaultHttpClient();
HttpGet request = new HttpGet(HTTP_BASE + string[0] + ".png");
HttpResponse response = dhc.execute(request);
BufferedInputStream webstream = new BufferedInputStream(response.getEntity().getContent());
d = BitmapFactory.decodeStream(webstream);
writeToSd(string[0], webstream, d);
}
catch (Exception ex) { ex.printStackTrace(); }
return d;
}
private void writeToSd(String string, BufferedInputStream webstream, Bitmap d) {
try {
webstream.mark(3);
webstream.reset();
File f = new File(Environment.getExternalStorageDirectory() + SD_DIR);
f.mkdirs();
File f2 = new File(f, string + ".png");
f2.createNewFile();
BufferedOutputStream fos = new BufferedOutputStream(new FileOutputStream(f2));
int len;
byte[] buffer = new byte[1024];
while ((len = webstream.read(buffer)) > 0) {
fos.write(buffer, 0, len);
}
webstream.close();
//fos.flush();
fos.close();
}
catch (Exception ex) {
ex.printStackTrace();
}
}
protected void onPostExecute(Bitmap result) {
if (result != null) {
iv.setImageBitmap(result);
vs.setDisplayedChild(1);
}
}
};
I don’t know for sure, but it seems likely that there is something wrong with the re-reading of the InputStream, even though it’s buffered. An image is quite a bit of data to hold in memory. Rather than doing
you could try to
This way you can write a full-sized image to disk (without having to buffer the stream and consume a lot of memory). Then, you can simply load the image from the sd card at the lowest sampling rate that works for your application, thus saving having a full-sized image ever in memory. Also, doing it this way would likely eliminate any issues you may or may not be having with the bufferedInputStream – I find them to be pretty finicky.