Homework 6

Due Thurs, Dec 2, 18:00

Exercise 1: (7 points)

Write a class definition to simulate a user account with a password (UML diagram below). The basic functionality that we want is to be able to allow the user to log in and out, and to reset the password. To log in, the correct password must be given (parameter of the logIn method). If an attempt is made to log in with the wrong password, the user will not get logged in. To reset the password, the current password must be given as well as the new password (if the current password is incorrect, the password will not be reset - it remains the same). Passwords must have at least 8 characters.

UserAccount

- loginID : String
- password : String
- loggedIn : boolean

+ setLoginID(String newLoginID) : void
+ getLoginID() : String
+ isLoggedIn() : boolean
- isPassword(String aPassword) : boolean
- isValidPassword(String aPassword) : boolean
+ setPassword(String curPassword, String newPassword) : void
+ logIn(String aPassword) : void
+ logOut() : void
+ equals(UserAccount otherUser) : boolean
+ toString() : String

First things first - declare the instance variables and write a stub for each method
New UserAccounts are created with the loginID "guest" and password "guestPassWord", with the user logged out. Insert the following constructor to initialize the instance variables:

/**

* Construct a UserAccount with loginID "guest", password "guestPassWord",

* and the user logged out.

public UserAccount()
{

loginID = "guest";

password = "guestPassWord";

loggedIn = false;

}

setLoginID changes the loginID
getLoginID simply returns the loginID
isLoggedIn returns a boolean indicating whether the user is currently logged in or not
isPassword is a private (helper) method to determine if the parameter matches the password. Since it is private, it can only be called by other methods within the class. There are 2 other methods (logIn and setPassword) that should call isPassword.
isValidPassword is a private (helper) method to determine if the parameter is a valid password. A valid password has at least 8 characters.
setPassword changes the password, but only if the curPassword is correct and newPassword is valid. If either of these conditions is not met, the password remains unchanged. You may print an error message if the password can't be set, but do not call System.exit(0) (doing so will make it impossible to run the junit tests).
logIn will log the user in if the parameter aPassword is the user's password. If the password is incorrect, print an error message (do not exit the program if the password is wrong).
logOut logs the user out - no password is required.
Two UserAccount objects are equal if the loginID's are equal and the passwords are equal
The toString method should return a String that contains the loginID and tells if the user is currently logged in or not, but should not include the password.
Be sure to include javadoc comments (method description, @param, and @return).

Exercise 2: (2 points)

Use UserAccountTest.java to partially test your class. When all of the tests pass, add 2 more tests:

test that the setPassword method does not reset the password when both the current password is incorrect and the new password is invalid
test that the equals method returns true even when one user is logged in and the other is logged out

Exercise 3: (1 point)

Open UserAccount.java in drjava.
From the menu select Tools -> Javadoc -> "Preview Javadoc for Current Document"

In the "Method Summary" section, you should see a list of all of the public method headers (not the private ones, though), including the first sentence of the method description. Click on the method names to see the full descriptions, parameters, and return values.

Make sure that the documentation is complete and correct for each public method.

You do not need to submit anything for exercise 3.

Submit the following files to Anne (javaiscl (at googlemail.com)):
UserAccount.java
UserAccountTest.java