Twitter Percent Encode

main.java

private static String percentEncode(String s){
        String result = "";
        for (int i=0; i<s.length(); i++){
            char check = s.charAt(i);
            if (Character.isLetter(check) || Character.isDigit(check) || check == '-' || check=='.' || check=='_' || check == '~' ){
                result+=check;
            }
            else{
                result+=("%"+Integer.toHexString(check));
            }
        }
        return result;
    }