句子逆序的解题思路

我是用split以空格为条件将句子分割，然后再倒序循环输出，非最后索引的输出要连同空格一起输出，最后一个只输出索引内容：
import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStreamReader;

public class Main {

public static void main(String[] args) throws IOException {

    BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
    String str;
    while ((str = br.readLine()) != null) {

        StringBuffer sb = new StringBuffer();

        String[] s = str.split(" ");
        for (int i = s.length-1; i >= 0; i--) {
            if(i>=0) sb.append(s[i]+" ");
            else sb.append(s[i]);
        }

        System.out.println(sb.toString());
    }


}

}