OnJava8-Examples/generics/GenericCast.java

// generics/GenericCast.java
// <20>2016 MindView LLC: see Copyright.txt
// We make no guarantees that this code is fit for any purpose.
// Visit http://mindviewinc.com/Books/OnJava/ for more book information.

class FixedSizeStack<T> {
  private int index = 0;
  private Object[] storage;
  public FixedSizeStack(int size) {
    storage = new Object[size];
  }
  public void push(T item) { storage[index++] = item; }
  @SuppressWarnings("unchecked")
  public T pop() { return (T)storage[--index]; }
}

public class GenericCast {
  public static final int SIZE = 10;
  public static void main(String[] args) {
    FixedSizeStack<String> strings =
      new FixedSizeStack<>(SIZE);
    for(String s : "A B C D E F G H I J".split(" "))
      strings.push(s);
    for(int i = 0; i < SIZE; i++) {
      String s = strings.pop();
      System.out.print(s + " ");
    }
  }
}
/* Output:
J I H G F E D C B A
*/