Revise the GenericStack class in Listing 19.1 to implement it using an array rather than an ArrayList. You should check the array size before adding a new element to the stack. If the array is full, create a new array that doubles the current array size and copy the elements from the current array to the new array.

Listing

1 public class GenericStack { private java.util.ArrayList list = new java.util.ArrayList (); 3 public int getSize() { return list.size(); 4. 5 6. public E peek() { return list.get (getSize() - 1); 10 11 public void push(E o) { list.add(o); 12 13 14 15 16 17 18 19 20 public E pop() { E o = list.get(getSize() - 1); list.remove(getSize() - 1); return o; 21 22 public boolean isEmpty() { return list.isEmpty(); 23 24 25 @0verride public String toString() { return "stack: 26 27 + list.toString(); 28 29 30 }