CODEWITHSUNDEEP
javagenericsarraylist
William V
William V

Reputation: 78

Generic ArrayLists in Java

I am working on making a game where each level has different mechanics, but I want to keep all the input handling, rendering, etc in one place. My approach is to have a Level class with all the needed methods, then each level is its own class (Intro, BossRoom, etc) that extends Level and override methods to change the parts that need to change for each without having to copy over all of the contents of Level for each class. I have a LevelManager class that will hold all of the reference to the levels, and I was wanting to use ArrayList to do this.

I've tried using ArrayList<Level>, ArrayList<?>, ArrayList<? extends Level>, and ArrayList<? instanceof Level> both when I declare and instantiate the variable. Nothing I've tried seems to work. Is there something is Java that does this or should I just have each Level as a variable?

Sorry for block of text, I'm new to SO and do not know a better way to word it.

Upvotes: 0

Views: 82

Answers (1)

davidxxx
davidxxx

Reputation: 131346

It should rather be straight. Here is a little example.

Base class :

public abstract class Level{
  ....
}

Edit : You could declare the Level class as abstract if you deem that it should not (no sense) or it cannot be (at least one method is abstract ) instantiated in your application. According to your context, it is likely.

Child class :

public class IntroLevel extends Level{
...
}

Other child class :

public class LevelOne extends Level{
...
}

Your Level Manager :

public class LevelManager{

  private List<Level> levels;

  // constructor
  public LevelManager(){
   levels = new ArrayList<Level>();
   levels.add(new IntroLevel());
   levels.add(new LevelOne());
   ...
  }

}

Upvotes: 1

Related Questions