java链表实现栈却显示“找不到或无法加载主类 ”该如何解决？

package com.company;

import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStreamReader;
import java.util.Iterator;
import java.util.ListIterator;
import java.util.Queue;
import java.util.Scanner;

public class LinkedStack<Item> {
    private Node first,last;
    private int N;

    public LinkedStack(int i) {

    }

    private class Node{
        Item item;
        Node next;
    }

    public boolean isEmpty(){
        return first == null;
    }

    public int size(){
        return N;
    }

    //在表头插入结点
    public void push(Item item){
        Node oldfirst = first;
        first = new Node();
        first.item = (Item) item;
        first.next = oldfirst;
        N++;
    }

    //从表头删除节点
    public Item pop(){
        Item item = first.item;
        first = first.next;
        N--;
        return item;
    }

    //在表尾插入结点
    public void push2(Item item){
        Node oldlast = last;
        last = new Node();
        last.item = (Item) "not";
        oldlast.next = last;
        N++;
    }

    public Iterator<Item> iterator(){
        return new ListIterator();
    }
    private class ListIterator implements Iterator<Item>{
        private Node current = first;
        public boolean hasNext(){
            return current != null;
        }
        public void remove(){

        }
        public Item next(){
            Item item = current.item;
            current = current.next;
            return item;
        }
    }

    public static void main(String[] args) throws IOException {
        LinkedStack<String> stack = new LinkedStack<>(100);

        System.out.println("Enter the statement:");
        BufferedReader reader = new BufferedReader(new InputStreamReader(System.in));
        String input = reader.readLine();
        String[] item = input.split(" ");
        for(String s:item){
            if (!s.equals("-")){
                stack.push(s);
            }else if (!stack.isEmpty()){
                System.out.println(stack.first.toString()+"left on stack");
                stack.pop();
            }
        }
        System.out.println("The Stack:");
        int number = stack.size();
        while (number != 0){
            System.out.print(stack.first.toString()+" ");
            stack.first = stack.first.next;
            number--;
        }
    }
}