/**
* Bencodes document
*
* @param doc Document to be bencoded
* @return Bencoded string of the provided document
* @throws LRException BENCODE_FAILED if document cannot be bencoded
*/
private String bencode(Map<String, Object> doc) throws LRException {
String text = "";
String encodedString = "";
// Bencode the provided document
try {
ByteArrayOutputStream s = new ByteArrayOutputStream();
BencodingOutputStream bencoder = new BencodingOutputStream(s);
bencoder.writeMap(doc);
bencoder.flush();
encodedString = s.toString();
s.close();
// Hash the bencoded document
MessageDigest md;
md = MessageDigest.getInstance("SHA-256");
md.update(encodedString.getBytes());
byte[] mdbytes = md.digest();
StringBuffer hexString = new StringBuffer();
for (int i = 0; i < mdbytes.length; i++) {
String hex = Integer.toHexString(0xFF & mdbytes[i]);
if (hex.length() == 1) {
hexString.append('0');
}
hexString.append(hex);
}
text = hexString.toString();
} catch (Exception e) {
throw new LRException(LRException.BENCODE_FAILED);
}
return text;
}
