You can store file in internal storage like this
try {
URL url = new URL(strUrl);
HttpURLConnection conn = (HttpURLConnection) url.openConnection();
conn.setDoInput(true);
conn.connect();
InputStream is = conn.getInputStream();
Bitmap bm = BitmapFactory.decodeStream(is);
ContextWrapper cw = new ContextWrapper(getApplicationContext());
File directory = cw.getDir("imageDir", Context.MODE_PRIVATE);
File file = new File(directory, System.currentTimeMillis() + ".png");
FileOutputStream fos = openFileOutput(file.getAbsolutePath(), Context.MODE_PRIVATE);
ByteArrayOutputStream outstream = new ByteArrayOutputStream();
bm.compress(Bitmap.CompressFormat.JPEG, 100, outstream);
byte[] byteArray = outstream.toByteArray();
fos.write(byteArray);
fos.close();
} catch (Exception e) {
}