单向链表的定义及基本操作

类型声明

public class ListNode<T> {    private T data;    private ListNode<T> next;    public ListNode(T data){        this.data = data;    }    public T getData() {        return data;    }    public void setData(T data) {        this.data = data;    }    public ListNode<T> getNext() {        return next;    }    public void setNext(ListNode<T> next) {        this.next = next;    }}