Cannot reference this before supertype constructor has been called

Question

I\'m attempting to implement a circular queue class in Java. And in doing so I had to created a node class to group together elements and pointers to the next node. Being ci

Answer 1

You cannot refer tho this (or super) in a constructor, so you should change your code like this:

public class Node{
    private Key key;
    private Node next;
    public Node(){
    key = null;
        next = this;
    }
    public Node(final Key k){
    key = null;
        next = this;
    }
    public Node(final Key k, final Node node){
        key = k;
        next = node;
    }
    public boolean isEmpty(){return key == null;}
    public Key getKey(){return key;}
    public void setKey(final Key k){key = k;}
    public Node getNext(){return next;}
    public void setNext(final Node n){next = n;}
}