实现泛型 Java LinkedList

Question

I'm pretty new to Java and I'm attempting to implement a Generic LinkedList Class in java. Below is the code yet it doesn't quite work right. I have some extra free time this semester and want to use this generic linkedlist to solve the linkedlist programming challenges in my interview test prep book. What am I doing wrong here? Why won't this work the way I want it to?

Thanks for the help in advance.

public class LinkedList {
    public static linkedlist ll;
    public static void main(String[] args) {
        // TODO Auto-generated method stub
        ll = new linkedlist();
        Node one = new Node(1);
        Node two = new Node(2);
        Node three = new Node(3);
        Node four = new Node(4);
        System.out.println("s");
    }
    public static class linkedlist<T>{
        public Node head;
        public Node tail;
        int size;
        @SuppressWarnings("unchecked")
        public linkedlist(){
            size = 0;
        }
        void add(Class<T> typeParameterClass){
            if(head == null){
                head = new Node(typeParameterClass);
            }
            Node temp = new Node(typeParameterClass);
            Node headCopy = head;
            if(headCopy != null){
                while(headCopy.getNext()!= null){
                    headCopy = headCopy.getNext();
                }
                headCopy.setNext(temp);
            }
            size++;
        }
    } 
    public static class Node<T>{
        //final Class<T> typeParameterClass;
        Class<T> value;
        int intValue;
        Node next = null ;
        Node prev = null;
        public Node(Class<T> typeParameterClass){
            value = typeParameterClass; 
        }
        public Node(int i) {
            intValue = i;
            // TODO Auto-generated constructor stub
        }
        public Node getNext() {
            // TODO Auto-generated method stub
            return next;
        }
        public Node getPrev() {
            return prev;
        }
        public void setNext(Node temp){
            next = temp;
        }
    }
}

Answer 1

You would first spent some reading about Java naming conventions. Class names start Uppercase; always; even for inner static classes. You would also avoid using too many inner static classes in the first place. In your example, there is absolutely no need to do it this way. You would rather put the methods that make up a LinkedList directly on the LinkedList class. You want that users of that class use that class; and not some inner static thing like LinkedList.linkedlist or LinkedList.Node.

You see, right now, your methods are all on the inner Node class. So, do you want to deal with Nodes each time when doing something about your List?!

Then you read about how generics work in general. Example:

Node one = new Node(1);

is probably not even compiling, but even when it does, it creates a raw type; as you do not have the type parameter there. You need something like:

Node<Integer> one = new Node<>(1);

instead - you have to tell the compiler what real type you want to use instead of that anonymous T.

In other words: start reading here . Right now, you have like 25% knowledge/understanding; and that is not enough to start coding.

That is about what can be said without further description from your side about "what is not working" in your code. And even then: as said; your code is on such a low scale of "understanding" that the only reasonable answer is: step back and learn about the things you want to use.