Question

HashMap:  We can use a HashMap to store key value pairs.  Reminder that only reference types can be used as the key or value.  It you want to use a number as the key then an Integer data type could be used but not an int primitive data type.

Create a class called Login which contains a HashMap as a private attribute.  It should also have an instance method called loadCredentials which accepts the two arrays.  It will load the HashMap with key/value pairs based on the two arrays below. The userNames should be the keys and the passwords the values.  The purpose of the HashMap is to allow us to obtain the user’s password given their username as the key. 

private static String[] userNameArray = {"John", "Steve", "Bonnie", "Kylie", "Logan", "Robert"};

private static String[] passwordArray = {"1111", "2222", "3333", "4444", "5555", "6666"};  

Create a login method in the Login class.  This method will prompt the user for a username and password. It will then return true or false based on whether or not the user enters valid username and password.  Note that the username should exist and the password associated with that username should match what is stored for that username in the hashmap.

 

Login

-userMap: HashMap<String,   String>

+loadCredentials(String[],   String[]): void +login: boolean

 

When the tutor application starts.  Call the method to ensure the credentials are loaded and pass the two arrays provided above.  Then continually prompt the user to login until they enter a valid username and password.  Provide an error message if login fails.  Once a valid username and password is entered the main menu is shown to the user and the program runs normally.

 

Sample I/O

Please login:   Username:   Sylvain                                         ß Note that the user can enter   a username that does not exist   Invalid login, please try again.   Username:   Bob   Invalid login, please try again.   Username:   John   Password:   1234                                           ß Note that the user can enter   an invalid password   Invalid login, please try again.   Username:   John   Password:   1111 Welcome John                        ß Welcome based on the userName Welcome to CIS Tutoring   (2021-02-22) ------------------------- - CIS Menu - 1-Add An Invoice - 2-Show Total So Far - 3-Show All Invoices - 4-Show All Distinct   Employees - X-eXit ------------------------- Option-->