src/main/java/com/firebase/security/token/JWTEncoder.java
public static String encode(JSONObject claims, String secret) {
        String encodedHeader = getCommonHeader();
        String encodedClaims = encodeJson(claims);

        String secureBits = new StringBuilder(encodedHeader).append(TOKEN_SEP).append(encodedClaims).toString();

        String sig = sign(secret, secureBits);

        return new StringBuilder(secureBits).append(TOKEN_SEP).append(sig).toString();
    }
public static String encode(JSONObject claims, String secret) {
        String encodedHeader = getCommonHeader();
        String encodedClaims = encodeJson(claims);

        String secureBits = new StringBuilder(encodedHeader).append(TOKEN_SEP).append(encodedClaims).toString();

        String sig = sign(secret, secureBits);

        return new StringBuilder(secureBits).append(TOKEN_SEP).append(sig).toString();
    }
Encode and sign a set of claims.

@param claims
@param secret
@return