generics "uses unchecked or unsafe operations" problem

[Dinah Gans]

Can someone help me understand why this gives me the following Notes?

I don't understand why my constructor doesn't seem to be using generics for myList even though when I created it I said it held generics? Thanks in advance for the help!

Note: InfiniteInt.java uses unchecked or unsafe operations.
Note: Recompile with -Xlint:unchecked for details.

public class InfiniteInt<Integer> extends DLList	//subclass of DLList
{
	//data
	//new Infinite Integer using generics - only holds Integers (or subclasses of)
	InfiniteInt<Integer> myList = new InfiniteInt<Integer>();

	//CONSTRUCTORS
	//constructor that takes no arguments and builds a linked list with that contains a value of 0
	public InfiniteInt()
	{
		this.myList.addLast(0);
	}

}

My DLList class uses objects:

public class DLList<E>

//addLast - puts an element at the end of the list
	public void addLast(E theElement)
	{
		//create a node to hold theElement
		Node<E> newNode = new Node<E>(theElement);

		//case1: what if the list is empty?
		if (head == null)
			head = tail = newNode;

		//case2,3: what if the list has something in it?
		else
		{
			tail.next = newNode;
			newNode.prev = tail;
			tail = newNode;
		}
	}

[Rob Spoor]

InfiniteInt extends the raw type DLList. You should move the Integer generic type to DLList instead:

public class InfiniteInt extends DLList<Integer>
{
    //data
    //new Infinite Integer using generics - only holds Integers (or subclasses of)
    InfiniteInt myList = new InfiniteInt(); // no longer needed to add <Integer> - InfiniteInt only works for Integer now

    //CONSTRUCTORS
    //constructor that takes no arguments and builds a linked list with that contains a value of 0
    public InfiniteInt()
    {
        this.myList.addLast(0);
    }
}

And you should know that Integer is final so there are no subclasses of Integer

[Dinah Gans]

Wow thanks!!! That solved all of the problems I was having with this & explains why it was telling me "DLList<Integer> cannot be applied to (int)" when I had changed both classes to have generics.

[Rob Spoor]

You're welcome.