字符串反转变形（asd zxc qwe -> qwe zxc asd）

public String reverse(String str){
    String s = "";
    String[] strings = str.split(" ");
    for (int i = strings.length - 1; i > 0 && i<strings.length ; i--) {
        s = strings[i] + " ";
    }
    return s;
}

asd zxc qwe -> qwe zxc asd