已经尝试修复了很多次，我不知道我哪里出错了

Question

I am very new to java and am trying to learn how to program it while working remotely which is very difficult for me. The assignment is to create an "ingredient" class that will ask for ingredients, validate the input, and then at the end print a list of ingredients. I have written and re-written this code about a dozen times and it never prints out correctly. It takes one too many loops through to get a correct output, and when the values stored in the variables during the execution print out incorrectly. This group is my last ditch effort as I am struggling so hard even though I'm putting in the work. Thanks again and take care.

package Stepping_Stones_Lab_2;
import java.util.Scanner;
import java.util.ArrayList;

public class MilestoneOne {

/**
 * 
  */

 public static void main(String[] args) {
 ArrayList<String> ingredientList = new ArrayList();
 ArrayList<String> recipeList = new ArrayList();
 
 //variable declaration
 double ingredientAmount = 0.0;
 double totalCalories = 0.0;
 int numberCaloriesPerUnit = 0;
 String recipeName; 
 String nameOfIngredient;
 String unitMeasurement; 
 Scanner scnr = new Scanner(System.in);
 
 boolean addMoreIngredients = true;
 
//recipie creation
 System.out.print("Please enter your new recipe name: ");
 recipeName = scnr.nextLine();
 recipeList.add(recipeName);
 
//This do-while loop is requesting ingredients until such time the user terminates the requests by typing n. If neither y or n is
//used the program will return an Invalid value error
 do {
    System.out.print("Would you like to enter an ingredient: (y or n): ");
    String reply = scnr.next().toLowerCase();
    scnr.nextLine();
    
    //the notes says use a switch but I have not been able to get a switch to work successfully despite many tries.
    if(reply.equals("y")) {
        System.out.print("Enter ingredient name: ");
         nameOfIngredient = scnr.nextLine();
              
         while (!nameOfIngredient.matches("[a-zA-Z_]+")){ //Validates input and loops until there is acceptable input for name
           System.out.print("Error: Please enter valid name of ingredient: ");   
           nameOfIngredient = scnr.next();
           }
         ingredientList.add(nameOfIngredient);
           
        System.out.println("Good job! The ingredient you entered is " + nameOfIngredient); 
 
            //Unit of measurement input and data validation
        System.out.print("Please enter the unit of measurement (cups, ounces, etc.): ");
         unitMeasurement = scnr.next();
 
         while (!unitMeasurement.matches("[a-zA-Z_]+")){ //Validates input and loops until there is acceptable input for unit measurement
           System.out.print("Error: Please enter valid unit of measurement: ");
           unitMeasurement = scnr.next();  
           }
 
        System.out.println("Good job! The unit of measurement for " + nameOfIngredient + " is " + unitMeasurement);
 
        //Amount of ingredient input and data validation
        System.out.print("Please enter the number of " + unitMeasurement + " of " + nameOfIngredient + " we'll need: ");
            
    
         while (!scnr.hasNextDouble()){//Validates input and loops until there is acceptable input for amount
           System.out.print("Error: Please enter the number of " + unitMeasurement + " of " + nameOfIngredient + " we'll need using numbers only: ");
           scnr.next();
           }
          ingredientAmount = scnr.nextDouble();
 
        System.out.println("Good job! The number of " + unitMeasurement + " of " + nameOfIngredient + " needs is " + ingredientAmount);
     
        //Number of calories per cup of ingredient input and data validation
        System.out.print("Please enter the number of calories per " + unitMeasurement + " of " + nameOfIngredient + ": "); 
 
         while (!scnr.hasNextInt()){
           System.out.print("Please enter the number of calories per " + unitMeasurement + " of " + nameOfIngredient + " using numbers only: ");
           scnr.next();
           }
 
          numberCaloriesPerUnit = scnr.nextInt();
 
        System.out.println("Good job! The number of calories per " + unitMeasurement + " of " + nameOfIngredient + " is " + numberCaloriesPerUnit);
  
        totalCalories = ingredientAmount * numberCaloriesPerUnit;
    
        System.out.println(recipeName + " uses " + ingredientAmount + " " + unitMeasurement + " and has " + totalCalories + " calories.");
                          }
    
    
    else if(reply.equals("n")){
        addMoreIngredients = false;
        System.out.println("Your ingredients for " + recipeName + " are as follows: ");
    }
    
    else {
        System.out.println("Invalid value!!");
    }
 }

while (addMoreIngredients);

for (int i = 0; i < ingredientList.size(); i++) {
    String ingredient = ingredientList.get(i);
    System.out.println(ingredient);
}
}
}

Answer 1

It works for me. Look at the following transcript.

Please enter your new recipe name: recipe name
Would you like to enter an ingredient: (y or n): y
Enter ingredient name: a
Good job! The ingredient you entered is a
Please enter the unit of measurement (cups, ounces, etc.): b
Good job! The unit of measurement for a is b
Please enter the number of b of a we'll need: 2
Good job! The number of b of a needs is 2.0
Please enter the number of calories per b of a: 3
Good job! The number of calories per b of a is 3
recipe name uses 2.0 b and has 6.0 calories.
Would you like to enter an ingredient: (y or n): y
Enter ingredient name: a2
Error: Please enter valid name of ingredient: aa
Good job! The ingredient you entered is aa
Please enter the unit of measurement (cups, ounces, etc.): bb
Good job! The unit of measurement for aa is bb
Please enter the number of bb of aa we'll need: 4
Good job! The number of bb of aa needs is 4.0
Please enter the number of calories per bb of aa: 8
Good job! The number of calories per bb of aa is 8
recipe name uses 4.0 bb and has 32.0 calories.
Would you like to enter an ingredient: (y or n): n
Your ingredients for recipe name are as follows: 
a
aa