Collections.<Entry<String, String>>emptyList());
// Compute the hash of the body.
byte[] hash = DigestUtils.sha(jsonBody);
byte[] encodedHash = Base64.encodeBase64(hash, false);
message.addParameter(OAUTH_BODY_HASH, new String(encodedHash, UTF_8));
// Add other parameters.
OAuthConsumer consumer = new OAuthConsumer(null, OAUTH_CONSUMER_KEY_DOMAIN + ":" + consumerKey,
consumerSecret, null);
consumer.setProperty(OAuth.OAUTH_SIGNATURE_METHOD, OAuth.HMAC_SHA1);