Using non-inherited methods of subclass

[jammas615]

Hi,

I have an Entity class.
It is abstract private fields and has getters and setters defined and only two abstract methods, update and render.

My other class which inherits Entity has more methods such as movement methods etc.

I have an ArrayList of type Entity declared in a class which adds the Player() class to it.

How can i use the non-inherited methods of the Player() class through an ArrayList().

What i want to do:

Class holding array:

ArrayList<Entity> entities = new ArrayList<Entity>();
entities.add(new Player(param, param));

Class which calls methods from Player():

Class.Class.entities.get(0).nonInheritedFunction();

Thanks.

[Tjstretch]

You could use casting.
Eg lets say we have to classes

public abstract class Foo
{
  public abstract void doFoo();
}

and

public class DefaultFoo extends Foo
{
  @Override
  public void doFoo()
  {
    System.out.println("A default foo");
  }
}

and

public class Bar extends Foo
{
  @Override
  public void doFoo()
  {
    System.out.println("Did foo");
  }
  public void doBar()
  {
    System.out.println("Did bar!");
  }
}

Then you had an arraylist holding foo and you want to use doBar, you would use casting.

ArrayList<Foo> foosAndBars = new ArrayList<Foo>();
foosAndBars.add(new DefaultFoo());
foosAndBars.add(new DefaultFoo());
foosAndBars.add(new Bar());

Now it's clear than only the foo at index 2 would be able to use doBar(). You would have to first check the type of each foo to see if it is a bar, than cast it if it is, than you could call doBar

for(Foo foo : foosAndBars)
{
  foo.doFoo(); 
  if(foo instanceof Bar)
  {
    Bar bar = (Bar) foo; //Cast foo to bar
    bar.doBar();
  }
}

This would output

A default foo
A default foo
A default foo
Did bar!

[doWhile]

If I understand your question clearly, you can class cast the Entity to a Player...but this sounds like poor design, as at runtime you may not be guaranteed that the Entity at the position in the List you are getting is an instance of Player (the instanceof operator will tell you, but again rethink the design)

[jammas615]

Hmmm. Redesign......
A massive entity tree or entity-component system...
............
Entity component I think.