Using generic classes and generic methods in Java is difficult

Java novice, I did search some examples, but I'm really sad

I have a node class that uses generics:

public class Node<T> {

    private int key;
    private T data;
    private Node<T> nextNode;

}

The node is good

public class GenericDictionary implements GenericDictionary_interface {

    private int capacity;
    private Node<T> [] slots;

    public void add (Node<T> newNode) {

    }
}

I think that's the way I write it I want genericdictionary to work with node objects

I received an error: "t cannot resolve to type."

The thing is, I don't know what it should look like

Solution

Your genericdictionary class also needs to be generic:

public class GenericDictionary<T> ...
{
}

At that time, you can use node < T > In class.

If the interface contains the add method, the interface should also be generic:

public class GenericDictionary<T> implements Dictionary<T>
{
}

By the way, I don't recommend using a named genericdictionary_ Interface... If there is only one implementation, you can call the interface genericdictionary and implement genericdictionaryimpl - a little scary, but quite common If there are multiple implementations, please name the implementation through some distinguished aspects