static String generateSignature () {
		String encoded = "";
		String type = "HmacSHA1";	
		try {
			byte[] key = ("KEY").getBytes("UTF-8");
			byte[] Sequence = ("hello").getBytes("UTF-8");
			
			Mac HMAC = Mac.getInstance(type);
			SecretKeySpec secretKey = new SecretKeySpec(key, type);

			HMAC.init(secretKey);
			byte[] Hash = HMAC.doFinal(Sequence);

			encoded = Base64.getEncoder().encodeToString(Hash);
		} catch (Exception e) {
			e.printStackTrace();
		}
		System.out.println(encoded);
	    return encoded;
	}