import java.util.*;public class Solution {    public String ReverseSentence(String str) {        if(str==null||str.length()==0){            return "";        }if(str.trim().equals("")){            return str;        }        String[] strings = str.split(" ");        List
     
       list = new ArrayList<>();        for(int i = strings.length - 1;i>=0;i--){            list.add(strings[i]);        }        StringBuffer stringBuffer = new StringBuffer();        for(int i =0;i