Pls help me with strings

import java.util.*;
public class ReverseString{
    public static void main(String[]args){
        Scanner input=new Scanner(System.in);
        StringBuffer buffer=new StringBuffer();
        System.out.println("Enter string: ");
        String str=input.nextLine();
        StringTokenizer stk=new StringTokenizer(str);
        while(stk.hasMoreTokens()){
           String st=stk.nextToken();
           String reverse = new StringBuffer(st).reverse().toString();
           buffer.append(reverse);
           buffer.append(" ");
        }
        System.out.println("Reverse: " + buffer.toString());
    }
}

import java.util.*;
public class ReverseString{
    public static void main(String[]args){
        Scanner input=new Scanner(System.in);
        StringBuffer buffer=new StringBuffer();
        System.out.println("Enter string: ");
        String str=input.nextLine();
        StringTokenizer stk=new StringTokenizer(str);
        while(stk.hasMoreTokens()){
           String st=stk.nextToken();
           String reverse = new StringBuffer(st).reverse().toString();
           buffer.append(reverse);
           buffer.append(" ");
        }
        System.out.println("Reverse: " + buffer.toString());
    }
}