cs1.java

// Represents a thing in the game world
interface GameObject {
  int getID();
}

// Store data
public abstract class Component extends GameObject {
    private static Class<? extends Component>[] idArray = new Class<? extends Component>[10];
    
    @Override
    public int getID() {
      return idArray[getClass()];
    }
}

// Manages a single component
interface ComponentSystem<T extends GameObject, C extends Component> {
  
  C add(T obj);
  C get(T obj);
  C remove(T obj);
  boolean has(T obj);

}

// Manages a set of bodies
interface ComponentContext<T extends GameObject> {
  
  int create(T obj);
  T destroy(int id);

  List<T> getAll();
  
}

// Finally: Manages a set of ComponentSystems, as well as the ComponentContext they act on
interface ComponentManager<T extends GameObject> {
  
  void add(ComponentSystem<T, ? extends Component> system);
  void remove(ComponentSystem<T, ? extends Component> system);
  
  public ComponentContext<T> getContext();
}