LinkedList方法

Question

我在打印信息时遇到问题。该程序以包含以下选项的菜单开始：

1. 添加员工
2. 删除员工
3. 打印员工信息
4. 退出

如果您想添加一名员工，它会询问您想添加多少，但我还没有这样做。 现在我只想打印出员工的名字和姓氏，然后打印出每个员工的循环。

主要

public static void main(String[] args) {
        // TODO Auto-generated method stub
        Scanner keyboard = new Scanner(System.in);
        System.out.println("1. Add Employee");
        System.out.println("2. Remove Employee");
        System.out.println("3. Print Employee Information");
        System.out.println("4. Exit");


        int option = keyboard.nextInt();
        keyboard.nextLine();//for the string buffer
        System.out.println("Enter employee first name: ");

            String firstName = keyboard.nextLine();
        System.out.println("Enter employee last name: ");
            String lastName = keyboard.nextLine();
        System.out.println("Enter employee address: ");
            String address = keyboard.nextLine();
        System.out.println("Enter employee city: ");
            String city = keyboard.nextLine();
        System.out.println("Enter employee state: ");
            String state = keyboard.nextLine();
        System.out.println("Enter employee zip: ");
            String zip = keyboard.nextLine();
        System.out.println("Enter employee age: ");
            int age = keyboard.nextInt();

            keyboard.nextLine();
            //for the string buffer

        Employee empList = new Employee(firstName, lastName, 
                address, city, state, zip, age);


        //populate employee class
        LinkedList ll = new LinkedList();

        ll.toString();
        System.out.println(ll);

    }

链表

public class LinkedList {
    private Node first = null;
    Node last;

    private class Node{
        Node next;
        Employee e;
        //Employee e;

        Node (Employee val, Node n){
             Employee emp = new Employee(val.getFName(), val.getLName(), val.getAddress(),
                     val.getCity(), val.getState(), val.getZip(), val.getAge());
             e = val;
        }

        Node(Employee val){
            this(val,null);
        }
        //SET with e, and GET from val
    }
    public LinkedList(){
        first = null;
        last = null;
    }

public void print(){
        Node ref = first;
        while (ref != null){
            System.out.print(ref.e + " ");
            ref = ref.next;
        }
    }
    public void add(Employee e){
        if(isEmpty()){
            first = new Node(e);
            last = first;
        }
        else{
            last.next = new Node(e);
            last = last.next;
        }
    }


    public String toString(){
        StringBuilder strBuilder = new StringBuilder();
        Node p = first;
        while(p != null){
            strBuilder.append(p.e + "\n");
            p = p.next;
        }
        return strBuilder.toString();
    }


}