How to capitalize the first letter of word in a string using Java?

Question

Example strings

one thousand only
two hundred
twenty
seven

How do I change the first character of a string in capital letter and not change

Answer 1

public static String capitalize(String str){
        String[] inputWords = str.split(" ");
        String outputWords = "";
        for (String word : inputWords){
            if (!word.isEmpty()){
                outputWords = outputWords + " "+StringUtils.capitalize(word);
            }
        }
        return outputWords;
    }