循环内验证

Question

我正在尝试在while循环中运行验证，以确保尚未使用ID，但是程序会不断跳过我的验证-有关如何使验证生效的任何建议？

public void addinventory items(ArrayList<Inventory> mv) {
Scanner scan = new Scanner(System.in);

System.out.println("Choose one of the following menu options (1,2,or 3): 
\n1. Update an item in the inventory");
System.out.println("2. Add a new inventory item");
System.out.println("3. Exit to main menu\n");
int choice = scan.nextInt();

while (choice == 2) {
    System.out.println("What is the ID of the inventory item?");
    String inventoryID = scan.nextLine();
    while (checkId(mv, inventoryID)) {
        System.out.println("This ID already exists, enter a different ID: ");
        inventoryID = scan.nextLine();
    }
    System.out.println("How many inventory items do you wish to add?");
    int numinventory items = scan.nextInt();
    scan.nextLine();
    System.out.println("What is the description?");
    String desc = scan.nextLine();
    System.out.println("How many stocks to did you purchase?");
    int num = scan.nextInt();
    System.out.println("What is the cost of the inventory item?");
    double cost = scan.nextDouble();
    System.out.println("What is the value of the inventory item?");
    double value = scan.nextDouble();

    Inventory inventory = new Inventory(inventoryID.toUpperCase(), desc, num, cost,
            value);

    mv.add(inventory);
    numinventory items--;

}