Reverse Words in a String

Given an input string, reverse the string word by word.

For example,
Given s = "the sky is blue",
return "blue is sky the".

反转单词，这题用javaapi可以很简单的做到

    public String reverseWords(String s) {
        if(s == null || s.isEmpty()){
            return s;
        }
        String[] array = s.trim().split(" ");
        StringBuilder sb = new StringBuilder("");
        for(int i = array.length - 1; i > -1; i--){
            if(array[i].isEmpty()){
                continue;
            }
            sb.append(array[i]);
            if(i != 0){
                sb.append(" ");
            }
        }
        return sb.toString();
    }