Java：使用getter从arraylist检索和打印项目

Question

I am writing a program to simulate a system in a coffee shop where the person who takes the orders of the customers gives a customer a token number and enters into a system the token number of the customer along with the items s/he has ordered. The recordOrder function carries out this operation which allows order details to be input. An order is represented by a token ID, tID, and an arrayList of strings representing the items in the order.

Here is what I have done so far:

import java.util.ArrayList;
import java.util.List;
import java.util.Scanner;

 public class Ques4 {

   private static class Order{
     private int tID;
     private int orderId;
     private String itemName;

    public Order(int tID,String itemName){
        this.tID=tID;
        this.itemName=itemName;

    }

    public int gettID() {
        return tID;
    }

    public void settID(int tID) {
        this.tID = tID;
    }

    public String getItemName() {
        return itemName;
    }

    public void setItemName(String itemName) {
        this.itemName = itemName;
    }

    /*public String toString(){
        return "Token num: "+gettID()+ " Item name: "+getItemName();
    }*/

}

public static void main(String[] args) {


    ArrayList<Order> listOfItems= new ArrayList<Order>();
    recordOrder(listOfItems);


}

    private static void recordOrder(ArrayList<Order> listOfItems){

        int n, tnum;
        int num_Orders;
        String item = null;

        Scanner sc= new Scanner(System.in);

        System.out.println("Enter the token number: ");
        tnum= sc.nextInt();


       System.out.println("Enter the number of items for token number: "+tnum);
       n=sc.nextInt();
       sc.nextLine();


    System.out.println("Enter the items: ");

    for(int i=0; i<n;i++){

        item=sc.nextLine();

       }
    listOfItems.add(new Order(tnum, item));


 for(Order list: listOfItems){
     System.out.println("Token num: "+list.gettID()+ " Item name: "+list.getItemName());}   


        }
  }

The problem is that only the last item which I enter is being printed out,that is, suppose I input token number as 9, number of items as 3 and the item names as cheesecake, burritos, tacos, only tacos is being printed out and the output will be like this:

Token num: 9 Item name: tacos

It should instead be:

Token num: 9 Item name: cheesecake burritos tacos

Answer 1

for(int i=0; i<n;i++){
    item=sc.nextLine();
    listOfItems.add(new Order(tnum, item));
}

Your logic of adding the items should be inside the loop. Since you are adding it outside the loop, only one element gets added(that is the last element)

EDIT: to print the required way:

System.out.print("Token num: "+list.gettID()+ " Item name:");
for(Order list: listOfItems){
     System.out.print(" "+list.getItemName());
}   
System.out.println();

Answer 2

I think you want this:

for(int i=0; i<n;i++){
    item += sc.nextLine();
}

listOfItems.add(new Order(tnum, item));

This will append the items to the String you're building each time for the for loop, instead of overwriting the variable each time.

Answer 3

If you have to add more items to one object, you will need to initialize itemName as an array of String.

String[] itemName;

And in your setter method, add to the string instead of replacing the whole value with the new one. This is why you get only the latest input value.

 public void setItemName(String itemName) {
        this.itemName.add(itemName);
    }

Similarly, you can handle the getter to output the String array.