Question

Be sure to include a message to the user explaining the purpose of the program before any other printing to the screen. Be sure to include information about which document codes are valid.

Within the main method, please complete the following tasks in java program:

Create a loop that allows the user to continue to enter two-character document designations until a sentinel value is entered (ex. “XX”).

If the user enters a valid document code, please echo that value back to the user. (Note: this is an additional requirement to those listed in the book.)

The exception message should provide clear feedback to the user (ex. “Invalid Document Designation”).

Should the user enter an invalid document designation, ensure the program will catch and handle the exception and the program will continue to function until the user chooses to end it using the sentinel value.

Include clear comments throughout the program that explain the well named variables and what functionality the various lines/small sections of code are completing as related to the execution of the program.

Answer 1

Please find my implementation:

import java.util.Scanner;

public class Driver {

   public static void main(String[] args) {

       // TODO Auto-generated method stub

       String str=null;

       int i=0;

       Scanner sc=new Scanner(System.in);

       System.out.println("Please enter the two character document designation,\n Please use XX to end the program");

       str=sc.nextLine();

       while(!str.equals("XX")) // If the document name is XX capital case, it will be exit

       {

           if(i>0)

           {

               System.out.println("Please enter the two character document designation,\n Please use XX to end the program");

               str=sc.nextLine();

           }

           // Reading the document name

           try

           {

               if(str.length()!=2) // If the length is not 2 then its a invalid document

               {

                   throw new InvalidDocumentCodeException("Invalid Document Designation"); // throwing the custom exception

               }

               else

               {

                   System.out.println("Open document"); // If its 2 then you can open document

               }

           }

           catch(InvalidDocumentCodeException ex) // catching the custom exception

           {

               ex.printStackTrace();

           }

           i++;

       }

   }

}

// Creating a custom Exception class

class InvalidDocumentCodeException extends Exception {

   // Constructor with some message

   public InvalidDocumentCodeException(String message)

   {

       super(message);

   }

}

Please enter the two character document designation, Please use XX to end the program 1223 com.InvalidDocumentCodeException: Invalid Document Designation at com.Driver.main Driver.java: 22) Please enter the two character document designation, Please use XX to end the progranm 12 Open document Please enter the two character document designation, Please use XX to end the progranm 12 Open document Please enter the two character document designation, Please use XX to end the progranm Open document Please enter the two character document designation, Please use XX to end the progranm