Reverse Words in a String III

原题链接

/** * Created by Joe on 2017/12/12. */public class P557 {    public String reverseWords(String s) {        if (s == null)            return null;        if (s == "") {            return "";        }        String[] strs = s.split(" ");        StringBuilder stringBuilder = new StringBuilder();        int index = 0;        for (String str : strs) {            StringBuilder tempBuilder = new StringBuilder(str);            String prefix = index == 0 ? "" : " ";            stringBuilder.append(prefix + tempBuilder.reverse());            index++;        }        return stringBuilder.toString();    }}

注：
String类并不提供reverse()方法，为此需要先将String变化成为StringBuilder类才可以使用内置提供的reverse()