// reflection/pets/Creator.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.
// Creates random Pets
package reflection.pets;
import java.util.*;
import java.util.function.*;
import java.util.stream.*;
import java.lang.reflect.InvocationTargetException;

public abstract class Creator implements Supplier<Pet> {
  private Random rand = new Random(47);
  // The different types of Pet to create:
  public abstract List<Class<? extends Pet>> types();
  @Override public Pet get() { // Create one random Pet
    int n = rand.nextInt(types().size());
    try {
      return types().get(n)
        .getConstructor().newInstance();
    } catch(InstantiationException |
            NoSuchMethodException |
            InvocationTargetException |
            IllegalAccessException e) {
      throw new RuntimeException(e);
    }
  }
  public Stream<Pet> stream() {
    return Stream.generate(this);
  }
  public Pet[] array(int size) {
    return stream().limit(size).toArray(Pet[]::new);
  }
  public List<Pet> list(int size) {
    return stream().limit(size)
      .collect(Collectors.toCollection(ArrayList::new));
  }
}