OnJava8-Examples/generics/IterableFibonacci.java

// generics/IterableFibonacci.java
// (c)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.
// Adapt the Fibonacci class to make it Iterable
import java.util.*;

public class IterableFibonacci
extends Fibonacci implements Iterable<Integer> {
  private int n;
  public IterableFibonacci(int count) { n = count; }
  @Override
  public Iterator<Integer> iterator() {
    return new Iterator<Integer>() {
      @Override
      public boolean hasNext() { return n > 0; }
      @Override
      public Integer next() {
        n--;
        return IterableFibonacci.this.get();
      }
      @Override
      public void remove() { // Not implemented
        throw new UnsupportedOperationException();
      }
    };
  }
  public static void main(String[] args) {
    for(int i : new IterableFibonacci(18))
      System.out.print(i + " ");
  }
}
/* Output:
1 1 2 3 5 8 13 21 34 55 89 144 233 377 610 987 1597 2584
*/