Reverse Words in a String III

Given a string, you need to reverse the order of characters in each word within a sentence while still preserving whitespace and initial word order.

Example 1:

Input: "Let's take LeetCode contest"
Output: "s'teL ekat edoCteeL tsetnoc"

Note: In the string, each word is separated by single space and there will not be any extra space in the string.

Solution:

class Solution {
    public String reverseWords(String s) {
        StringBuilder res = new StringBuilder();
        String[] str = s.split(" ");
        for (String token : str) {
            res.append(new StringBuilder(token).reverse());
            res.append(" ");
        }
        res.setLength(res.length() - 1);
        return res.toString();
    }
}