HMACSHA256 Signature plus Base64 encoding plus URL encoding

/**
* First Use HmacSHA256 signature, then use BASE64 encoding, finally URL encoding
*SIGNATUREREQSTR: Data to encrypt
* Secretkey: Key
*/
public static string Getsignature (String signaturereqstr,string secretkey) {
    Mac Sha256_hmac;
    String result = "";
    try {
        Sha256_hmac = Mac.getinstance ("HmacSHA256");
        Secretkeyspec Secret_key = new Secretkeyspec (Secretkey.getbytes (), "HmacSHA256");
        Sha256_hmac.init (Secret_key);
        result = Base64.encodebase64string (Sha256_hmac.dofinal (Signaturereqstr.getbytes ()));
        result = Urlencoder.encode (result);
    } catch (InvalidKeyException e) {
        E.printstacktrace ();
    } catch (NoSuchAlgorithmException e) {
        E.printstacktrace ();
    }
    return result;
}

HMACSHA256 Signature plus Base64 encoding plus URL encoding