Question

Help Please on JAVA Project: Validating the input is where I need help. Thank you

Requirements description:

Assume you work part-time at a sandwich store. As the only employee who knows java programming, you help to write a sandwich ordering application for the store.

The following is a brief requirement description with some sample output.

1. Selecting bread

When the program starts, it first shows a list/menu of sandwich breads and their prices, then asks a user to select a bread by entering an integer number. A sample output is as follows.

=== Select Sandwich Bread: ===

1 White Bread $1.5

2 Wheat Bread $1.8

3 French Bread $2.0

4 Organic Bread $2.3

Select a bread [1, 4]:

You are supposed to validate the input.

If the user enters a letter or a number not between 1 and 4, the user will see an error message.

A sample output for invalid number is as follows.

Select a bread [1, 4]: 0

Error! Number must be greater than 0.

Select a bread [1, 4]:

In your program, you can hard-code the information for sandwich breads (i.e., bread names and prices) shown above, such as “1 White Bread $1.5” and use the hard-code price, such as 1.5, for calculation of a total price of the order.

2. Selecting vegetables

After the user provides a right bread number for bread selection, the program asks the user to select vegetables. A sample output is as follows. Again, input validation is needed.

=== Select Sandwich Vegetables: ===

1 red onions $0.10

2 olives $0.10

3 pickles $0.10

4 lettuce $0.20

5 green peppers $0.25

6 tomatoes $0.30

7 cheese $0.49

8 Quit vegetable selection

Select vegetables: [1, 8]:

You hard-code the vegetables information as shown above, such as “ 1 red onions $0.10” and use the hard-code price, such as 0.10, for calculation of the total price of the order.

After the user makes a choice for vegetable, such as 2 for olives. The program continues asking for selecting a vegetable so that the user can have multiple vegetables for one sandwich. The user can enter “8” to quit vegetable selection. A sample output is as follows.

=== Select Sandwich Vegetables: ===

1 red onions $0.10

2 olives $0.10

3 pickles $0.10

4 lettuce $0.20

5 green peppers $0.25

6 tomatoes $0.30

7 cheese $0.49

8 Quit vegetable selection

Select vegetables: [1, 8]: 2

=== Select Sandwich Vegetables: ===

1 red onions $0.10

2 olives $0.10

3 pickles $0.10

4 lettuce $0.20

5 green peppers $0.25

6 tomatoes $0.30

7 cheese $0.49

8 Quit vegetable selection

Select vegetables: [1, 8]:

3. Selecting meat

After vegetable selection, the program shows meat selection. A sample output is as follows.

=== Select Sandwich Vegetables: ===

1 red onions $0.10

2 olives $0.10

3 pickles $0.10

4 lettuce $0.20

5 green peppers $0.25

6 tomatoes $0.30

7 cheese $0.49

8 Quit vegetable selection

Select vegetables: [1, 8]: 8

=== Select Sandwich Meat: ===

1 Ham $0.9

2 Roasted Chicken Breast $1.0

3 Turkey Breast $1.1

4 Roast Beef $1.5

5 Quit meat selection

Select meat [1, 5]:

Input validation is needed and works as before. Unlike vegetable selection which allows selecting multiple vegetables, meat selection does not repeat after the user enters a valid number between 1 and 5.

You hard-code the information for meat shown above, such as “1 Ham $0.9” and use the hard-code price, such as 0.9, for calculation of the total price of the order.

4. Entering a customer’s name

After making a meat selection, the program asks for the user’s name so that the user can enter text like John or John Smith.

=== Select Sandwich Meat: ===

1 Ham $0.9

2 Roasted Chicken Breast $1.0

3 Turkey Breast $1.1

4 Roast Beef $1.5

5 Quit meat selection

Select meat [1, 5]: 4

Enter customer's name: John Smith

5. Displaying and writing order line information

After entering a name, the program prints details for this order line in computer monitor. The information includes the six fields: date and time, customer name, bread, vegetable(s), meat, and a (formatted) total price, and each field is separated by a tab, /t. A sample output to the monitor is as follows.

Enter customer's name: John Smith

Jul 6, 2016 10:35:43 AM John Smith Organic Bread lettuce, tomatoes, green peppers Roast Beef $4.55

Continue to order more sandwich? (y/n):

For your reference, the date and time is created by the following statements.

Date now = new Date();

DateFormat defaultDate = DateFormat.getDateTimeInstance(DateFormat.MEDIUM, DateFormat.MEDIUM);

String time = defaultDate.format(now);

Multiple vegetables are separated by commas

Besides showing on monitor, the same order line content is written (appended) to a text file named orderline.txt and each order line occupies one line in the text file. Here is a specific example for an order in the orderline.txt.

2018/07/05 20:34:17 John Smith Organic Bread lettuce, tomatoes, green peppers Roast Beef $4.55

Your program needs to create the output file, named orderline.txt, if it doesn’t exist yet, and later appends (not overwrite) order line information to the file. So next time when your program is executed, new order information will be appended to the receipt.txt file. You must use a relative path when creating an output stream writer object. For simplicity, we don’t record any information about the sales clerk and one order includes only one sandwich.

6. Repeating the order process

Continue to order more sandwich? (y/n):

If the user enters y or Y in the above prompt, the whole order process repeats by asking the user to select a sandwich bread, vegetable(s), meat, and enter a customer name, etc.

Design requirements:

You must have at least the following java classes. You may have additional classes if you want.

[1] a SandwichOrder class to simulate the SandwichOrder entity in real world, which has fields of bread, vegetables, meat, and price of the sandwich, customer name, the string value of time stamp (refer to the prior sample code) and corresponding methods. This class also provides a method to append the content of an order’s content to the output text file, receipt.txt. (SandwichOrder.java)

[2] a java application, named SandwichApp.java, that contains a main method. This class interacts with SandwichOrder class.

Answer 1

SOURCE CODE:

import java.util.*;
import java.text.DateFormat;
import java.util.Date;
import java.io.*;
import java.math.RoundingMode;
import java.text.DecimalFormat;
class SandwichOrder    //sandwichorder class
{
   String bread;
   String vegetables="";
   String meat;
   double price;
   String customername;
   String time;
   void appendToFile(String str) throws Exception //method for appending data to text file
   {
       String fileName = "orderline.txt";
        try {
            File file = new File(fileName);
           FileWriter fr = new FileWriter(file, true);
           BufferedWriter br = new BufferedWriter(fr);
           PrintWriter pr = new PrintWriter(br);
           pr.println(str);
           pr.close();
           br.close();
           fr.close();
        }
        catch (IOException e) {
            System.out.println("Exception Occurred" + e);
        }
   }
}
class SandwichApp
{
   public static void main(String[] args) throws Exception
   {
       int opt;
       double p=0;
       Scanner sc=new Scanner(System.in);
       while(true)
       {
           String vegetable="";
           SandwichOrder s=new SandwichOrder();
           while(true)       //logic for selecting sandwich bread
           {
               System.out.println("=== Select Sandwich Bread: ===\n1 White Bread $1.5\n2 Wheat Bread $1.8\n3 French Bread $2.0\n4 Organic Bread $2.3\n");
               System.out.println("Select a bread [1, 4]:");
               opt=sc.nextInt();
               if(opt<1)
               {
                   System.out.println("Error! Number must be greater than "+" "+opt);
               }
               else if(opt>4)
               {
                   System.out.println("Error! Number must be less than "+" "+opt);
               }
               else if(opt==1)
               {
                   s.bread="WhiteBread";
                   p=p+1.50;
                   break;
               }
               else if(opt==2)
               {
                   s.bread="WheatBread";
                   p=p+1.80;
                   break;
               }
               else if(opt==3)
               {
                   s.bread="FrenchBread";
                   p=p+2.00;
                   break;
               }
               else if(opt==4)
               {
                   s.bread="OrganicBread";
                   p=p+2.30;
                   break;
               }
           }
           while(true)   //logic for selecting sandwitch vegetables
           {
               System.out.print("=== Select Sandwich Vegetables: ===\n1 red onions $0.10\n2 olives $0.10\n3 pickles $0.10\n4 lettuce $0.20\n");
               System.out.println("5 green peppers $0.25\n6 tomatoes $0.30\n7 cheese $0.49\n8 Quit vegetable selection");
               System.out.println("Select vegetables: [1, 8]:");
               opt=sc.nextInt();
               if(opt<1)
               {
                   System.out.println("Error! Number must be greater than "+" "+opt);
               }
               else if(opt>8)
               {
                   System.out.println("Error! Number must be less than "+" "+opt);
               }
               if(opt==1)
               {
                   vegetable=vegetable+"red onions"+",";
                   p=p+0.10;
               }
               else if(opt==2)
               {
                   vegetable=vegetable+"olives"+",";
                   p=p+0.10;
               }
               else if(opt==3)
               {
                   vegetable=vegetable+"pickles"+",";
                   p=p+0.10;
               }
               else if(opt==4)
               {
                   vegetable=vegetable+"lettuce"+",";
                   p=p+0.20;
               }
               else if(opt==5)
               {
                   vegetable=vegetable+" green peppers"+",";
                   p=p+0.25;
               }
               else if(opt==6)
               {
                   vegetable=vegetable+"tomatoes"+",";
                   p=p+0.30;
               }
               else if(opt==7)
               {
                   vegetable=vegetable+"cheese"+",";
                   p=p+0.49;
               }
               else if(opt==8)
               {
                   break;
               }  

           }
           s.vegetables=vegetable.substring(0,(vegetable.length()-2));    //removing , at the end of the string
           System.out.println("veg "+s.vegetables);
           while(true) //logic for selecting sandwich meat
           {
               System.out.print("=== Select Sandwich Meat: ===\n1 Ham $0.9\n2 Roasted Chicken Breast $1.0\n3 Turkey Breast $1.1\n");
               System.out.println("4 Roast Beef $1.5\n5 Quit meat selection");
               opt=sc.nextInt();
               if(opt<1)
               {
                   System.out.println("Error! Number must be greater than "+" "+opt);
               }
               else if(opt>5)
               {
                   System.out.println("Error! Number must be less than "+" "+opt);
               }
               else if(opt==1)
               {
                   s.meat="Ham";
                   p=p+0.90;
                   break;
               }
               else if(opt==2)
               {
                   s.meat="Roasted chicken Breast";
                   p=p+1.00;
                   break;
               }
               else if(opt==3)
               {
                   s.meat="Turkey Breast";
                   p=p+1.10;
                   break;
               }
               else if(opt==4)
               {
                   s.meat="Roasted Beef";
                   p=p+1.50;
                   break;
               }
               else if(opt==5)
               {
                   break;
               }
      
           }
           sc.nextLine();
           System.out.print("Enter customer's name:");   //reading customer name
           String name=sc.nextLine();
           s.customername=name;

           Date now = new Date();
           DateFormat defaultDate = DateFormat.getDateTimeInstance(DateFormat.MEDIUM, DateFormat.MEDIUM);
           String t = defaultDate.format(now);
           s.time=t;
           DecimalFormat twoDForm = new DecimalFormat("#.##");
           p=Double.valueOf(twoDForm.format(p));
           s.price=p;
           System.out.println(s.time+"\t"+s.customername+"\t"+s.bread+"\t"+s.vegetables+"\t"+s.meat+"\t"+"$"+s.price);
           String str=""+s.time+"\t"+s.customername+"\t"+s.bread+"\t"+s.vegetables+"\t"+s.meat+"\t"+"$"+s.price;
           s.appendToFile(str);   //calling appendToFile method
           System.out.println("Continue to order more sandwich? (y/n):");
           char c=sc.next().charAt(0);
           if(c=='y')
           {
               continue;
           }
           else
           {
               break;
           }
       }
      

   }
}

OUTPUT:

ORDERLINE.TXT: