Lab 4: Check the Password Before You Wreck the Password

Due by the end of class

Your mission is to write a pro-active password checker that checks to make sure that a user entered password meets certain requirements. You must implement a simple program that prompts the user for two String values, a password and the same password again for confirmation.

For the purposes of this lab, a legal password must have all of the following properties:

• Length of at least 8 characters
• Starts with a lower case letter
• Ends with a numerical digit
• Is exactly equal to the repetition of the password typed for confirmation

Specification

Create a project called Lab4. Add a class called Password.

Complete your program to prompt the user to enter a password and a confirmation as explained above. If the password is shorter than 8 characters, print Password is too short! Otherwise, if the password does not start with a lower case letter, print Password must start with a lower case letter! Otherwise, if the password does not end with a digit, print Password must end with a digit! Otherwise, if the password does not match the confirmation, print Passwords do not match! Finally, if all the conditions are satisfied, print Password is valid!

To get the length of the password, you will have to use the length() method on the String object. To get the first and last characters of the password, you'll have to use the charAt() method. A lower case letter will be between 'a' and 'z'. A digit will be between '0' and '9'. Remember that the character values for numerical digits are not the same as the values of the numbers themselves. You will also need to use the equals() method to compare the two String values. One of the trickier problems with this lab is that you want to test for the negation of the conditions given above.

Below are several sample cases. The last example is a valid password, but the remainder are not. Try to match the sample output as closely as possible. User input is shown in green. Note that the passwords will be visible, not masked by dots, stars, asterisks, or similar. Making a program mask input is beyond the scope of this class. Note also that you should not test your program with passwords that contain a space since spaces will interfere with the operation of Scanner input.

Short Password

Enter a password: dang
Enter it again:   dang
Password is too short!

Starts Wrong

Enter a password: Zoomzoom9
Enter it again:   Zoomzoom9
Password must start with a lower case letter!

Ends Wrong

Enter a password: tellmeaboutit
Enter it again:   tellmeaboutit
Password must end with a digit!

Doesn't Match

Enter a password: rasputin99
Enter it again:   rasputan99
Passwords do not match!

Valid Password

Enter a password: wombat42
Enter it again:   wombat42
Password is valid!

Turn In

Turn in your code by uploading Password.java from the Lab4\src folder wherever you created your project to Blackboard. Do not upload the entire project. I only want the Password.java file.

All work must be done individually. Never look at someone else's code. Please refer to the course policies if you have any questions about academic integrity. If you have trouble with the assignment, I am always available for assistance.