DLLNode.java

/*****************************************************
 * class DLLNode
 * Implements a node, for use in lists and other container classes.
 *****************************************************/

public class DLLNode<T> {

    private T _cargo;    //cargo may only be of type T
    private DLLNode<T> _nextNode, _prevNode; //pointers to next, prev DLLNodes


    // constructor -- initializes instance vars
    public DLLNode(T value, DLLNode prev, DLLNode next) {
        _cargo = value;
        _nextNode = next;
        _prevNode = prev;
    }


    //--------------v  ACCESSORS  v--------------
    public T getCargo() { return _cargo; }

    public DLLNode<T> getNext() { return _nextNode; }

    public DLLNode<T> getPrev() { return _prevNode; }
    //--------------^  ACCESSORS  ^--------------


    //--------------v  MUTATORS  v--------------
    public T setCargo(T newCargo) {
        T foo = getCargo();
        _cargo = newCargo;
        return foo;
    }

    public DLLNode setNext(DLLNode newNext) {
        DLLNode foo = getNext();
        _nextNode = newNext;
        return foo;
    }

    public DLLNode setPrev(DLLNode newPrev) {
        DLLNode foo = getPrev();
        _prevNode = newPrev;
        return foo;
    }
    //--------------^  MUTATORS  ^--------------


    // override inherited toT
    public String toString() { return _cargo.toString(); }


    //main method for testing
    public static void main(String[] args) {

        //Below is an exercise in creating a linked list...

        /*********************
        //Create a node
        DLLNode first = new DLLNode("cat", null);
        //Create a new node after the first
        first.setNext(new DLLNode("dog", null));
        //Create a third node after the second
        first.getNext().setNext(new DLLNode("cow", null));
        DLLNode temp = first;
        while(temp != null) {
        System.out.println(temp);
        temp = temp.getNext();
        }
         ***********************/
    }//end main
}