Class Part

reflection/RegisteredFactories.java:10–29

import java.util.stream.*;

class Part implements Supplier<Part> {
  @Override public String toString() {
    return getClass().getSimpleName();
  }
  static List<Supplier<? extends Part>> prototypes =
    Arrays.asList(
      new FuelFilter(),
      new AirFilter(),
      new CabinAirFilter(),
      new OilFilter(),
      new FanBelt(),
      new PowerSteeringBelt(),
      new GeneratorBelt()
    );
  private static Random rand = new Random(47);
  @Override public Part get() {
    int n = rand.nextInt(prototypes.size());
    return prototypes.get(n).get();
  }
}

class Filter extends Part {}