（JAVA）为我的自动贩卖机做while循环

这个项目我用带开关盒的do while循环来检查输入的盒是否匹配。我运行代码，但结果不是我想要的。我期望的是，如果用户键入错误的大小写，则do while循环将循环回到用户需要输入大小写的输入。

这是代码

package vending.machine;
    import java.util.Scanner;
    import java.util.*;
    import java.util.ArrayList;
    import static vending.machine.adddrinks.drinksList;

public class VendingMachine {
    public static void main (String []args){
        Scanner sc= new Scanner(System.in);

        double money;
        double total;
        double balance;

        do{
            System.out.println("\nPlease insert money:");
            money = sc.nextDouble();
            if(money < 1.2){
                System.out.println("Not enough money");
            }
        }while(money < 1.2);
        System.out.println("What drinks are you looking for");
        adddrinks.showDrinks();
        adddrinks.viewDrinks();

        System.out.print("Select: 1 or 2 or 3 or 4\n");
        int select=sc.nextInt();

        do{
            switch(select){
                case 1:{
                    total = adddrinks.drinksList.get(0).getdrinkPrice();
                    balance = money - total;
                    System.out.println("Here is your balance: " + balance);
                    break;
                }
                case 2:{
                    total = adddrinks.drinksList.get(1).getdrinkPrice();
                    balance = money - total;
                    System.out.println("Here is your balance: " + balance);
                    break;
                }
                case 3:{
                    total = adddrinks.drinksList.get(2).getdrinkPrice();
                    balance = money - total;
                    System.out.println("Here is your balance: " + balance);
                    break;
                }
                case 4:{
                    total = adddrinks.drinksList.get(3).getdrinkPrice();
                    balance = money - total;
                    System.out.println("Here is your balance: " + balance);
                    break;
                }

                default:{
                    System.out.println("Invalid");
                    break;
                }
            }

        }while(select<5);
    }
}

这是结果 在这里输入图像描述

问题来源：Stack Overflow