Coding Buat Balik Kalimat

Buat temend-temend yang bingung cara buat balik kata pake java, bisa liat di sini....
^-^"...

import java.util.Scanner;

public class Stack1 {
public static void main(String[] args) {
Scanner aaa = new Scanner (System.in);

String input;
System.out.print("Masukkan kata yang ingin dibalik : ");
input = aaa.nextLine();
int stackSize = input.length();

Stack theStack = new Stack(stackSize);

for (int j = 0; j < input.length(); j++) {
char ch = input.charAt(j);
theStack.push(ch);
}

while (!theStack.isEmpty()) {
char ch = theStack.pop();
System.out.println(ch);
}
}
}

class Stack {
private int maxSize;

private char[] stackArray;

private int top;

public Stack(int s) {
maxSize = s;
stackArray = new char[maxSize];
top = -1;
}

public void push(char j) {
stackArray[++top] = j;
}

public char pop() {
return stackArray[top--];
}

// public char peek() {
// return stackArray[top];
// }

public boolean isEmpty() {
return (top == -1);
}

// public boolean isFull() {
// return (top == maxSize - 1);
// }
}