How do I access an inner class constructor from a derived class?

Question

For the below Ocean class,

public class Ocean {

    /**
     * Define any variables associated with an Ocean object here. These
     * variables MUST be private.
     */
    // width of an Ocean
    private final int width;
    // height of an Ocean
    private final int height;

    class Critter {

        /**
         * Defines a location of a Critter in an Ocean.
         */
        Point location;

        public Critter(int x, int y) {
            location = new Point(x,y);
        }

        public Point getLocation() {
            return location;
        }
    }

    private Critter[][] oceanMatrix;
}

I would like to access constructor Critter in above class from below class Shark constructor.

class Shark extends Ocean implements Behaviour {

    public Shark(int x, int y, int hungerLevel) {
        super(x,y);
    }
}

How do I access Critter class constructor from Shark class constructor?

Answer 1

It seems like you should extend Critter instead of Ocean:

class Shark extends Ocean.Critter implements Behaviour{
...
    public Shark(int x, int y, int hungerLevel){
        super(x,y);

    }
...
}

For this to work, Critter needs to be a static inner class. I don't know how much of this design is yours, but inner classes should be limited to classes that are strongly dependent on each other, this isn't the case here. If you can, take Critter out of Ocean.

Answer 2

只要Shark与Ocean在同一包中，并且将static修饰符添加到Critter的类声明中，您就应该能够使用new Ocean.Critter()访问Critter 。