public String getContentHashCode() {
InputStream stream = null;
try {
final MessageDigest hash = MessageDigest.getInstance("SHA-256");
stream = File.getInputStream();
final byte[] buffer = new byte[2048];
while (true) {
final int nread = stream.read(buffer);
if (nread == -1) {
break;
}
hash.update(buffer, 0, nread);
}
final Formatter f = new Formatter();
for (byte b : hash.digest()) {
f.format("%02X", b & 0xFF);
}
return f.toString();
} catch (IOException e) {
return null;
} catch (NoSuchAlgorithmException e) {
return null;
} finally {
if (stream != null) {
try {
stream.close();
} catch (IOException e) {
}
}
}
}
