OnJava8-Examples/collections/CrossCollectionIteration.java

// collections/CrossCollectionIteration.java
// (c)2021 MindView LLC: see Copyright.txt
// We make no guarantees that this code is fit for any purpose.
// Visit http://OnJava8.com for more book information.
import reflection.pets.*;
import java.util.*;

public class CrossCollectionIteration {
  public static void display(Iterator<Pet> it) {
    while(it.hasNext()) {
      Pet p = it.next();
      System.out.print(p.id() + ":" + p + " ");
    }
    System.out.println();
  }
  public static void main(String[] args) {
    List<Pet> pets = new PetCreator().list(8);
    LinkedList<Pet> petsLL = new LinkedList<>(pets);
    HashSet<Pet> petsHS = new HashSet<>(pets);
    TreeSet<Pet> petsTS = new TreeSet<>(pets);
    display(pets.iterator());
    display(petsLL.iterator());
    display(petsHS.iterator());
    display(petsTS.iterator());
  }
}
/* Output:
0:Rat 1:Manx 2:Cymric 3:Mutt 4:Pug 5:Cymric 6:Pug
7:Manx
0:Rat 1:Manx 2:Cymric 3:Mutt 4:Pug 5:Cymric 6:Pug
7:Manx
0:Rat 1:Manx 2:Cymric 3:Mutt 4:Pug 5:Cymric 6:Pug
7:Manx
5:Cymric 2:Cymric 7:Manx 1:Manx 3:Mutt 6:Pug 4:Pug
0:Rat
*/