java stack implimentation

gistfile1.java

class Stack {
  private Object[] array;
  private int tos = -1;
  private int size;

  Stack(int size) {
    this.size = size;
    array = new Object[size];
  }

  public void push(Object element) {
    tos++;
    array[tos] = element;
  }

  public Object pop() {
    Object obj = array[tos];
    tos--;
    return obj;
  }

  public boolean is_full() {
    return tos == size-1;
  }

  public boolean is_empty() {
    return tos == -1;
  }

  public void printStack() {
    for(int i=0; i<size; i++) {
      System.out.println(array[i]);
    }
  }
}