Implement the following class name Authenticator:

State

An array of type User (use a capacity of 100 I would recommend using a class constant the way I did in the 06-Array class of Lecture 2).

An integer size

Behavior

A constructor accepting a file name, that opens a Scanner on the file and reads in User objects

A method named authenticate that accepts a username and password and attempts to authenticate them against the User array (by doing a search).

Not finding the username in the array causes an exception to be thrown

finding the username, but not matching the password (via verifyPassword) causes an exception with a different message to be thrown (this one with the password hint included).

See below for the exact exception messages expected

The return type of the method is void, i.e., the method returns nothing if the username and password are matched; otherwise an exception is thrown, as described above. (This is a common pattern for authentication methods if everything is fine, the method simply returns, otherwise it throws an exception.)

The name of your class should be Authenticator. Please remove the public attribute from the class header.

Your class is tested by a AuthenticatorApp class that reads in Users from a file using your read method, loads them into an array and prompts the keyboard for a login sequence (username/password).

For example, if the file users.data contains:

weiss puppy2 woof-woof arnow java cuppa sokol brooklyn college 

here are some sample excutions of the program:

username? arnow password? java Welcome to the system

Sample Test Run #2

Given the same users.data file as above, execution of the program should look like:

username? weiss password? dontremember *** Invalid password - hint: woof-woof username? weiss password? puppy2 Welcome to the system

Sample Test Run #3

Given the same users.data file as above, execution of the program should look like:

username? sokol password? CUNY *** Invalid password - hint: college username? sokol password? SUNY *** Invalid password - hint: college username? sokol password? BC *** Invalid password - hint: college Too many failed attempts... please try again later

Assuming the existence of the Authenticator class of Lab 4.4, code an AuthenticatorApp application that reproduces the behavior of the sample runs of Lab 4.4, i.e., your app should instantiate an Authenticator object passing it the filename users.data, and then proceed to prompt the user at the keyboard for a user name and password; handling any exceptions in the manner described in Lab 4.4.

The name of your class should be AuthenticatorApp.