Cipher System

[Isaac93]

Hi everyone, I have an assignment where I have to create a cipher system. The problem is that all cipher systems' classes and their respective keys have to be managed by a module based on the façade design pattern and I have no idea how to do it? Please I really need help.

[Norm]

First have you studied the façade design pattern and understand what it means to use it in a program design?
If not, copy the parts you do not understand here and ask questions about it.

[Fubarable]

You can read up on the structure of this pattern here: Facade Pattern

[Isaac93]

Yes I have done an overview of all the design patterns and also found examples but still can't fully understand the question. I have a copy of the assignment sheet the problem is where it comes to both the cipher module and ui model pages 5 and 7. Thanks a lot for the help. https://viewer.zoho.com/docs/g8acci - the assignment sheet

[Fubarable]

I believe that your assignment tells you what must be done:

This module should be designed to conform to the Facade Design Pattern which specifies the following
1. An interface which defines the signature of all methods to be provided by the module.
2. An implementation class (one or more) which implements the module interface.

And so I would do just this: figure out what general methods would be needed by all Cipher classes, and create an interface with just those methods. Then have all Cipher classes implement that interface.

[Norm]

Cross posted at Java Assignment Problem - Java | DaniWeb

[Fubarable]

Cross posted at Java Assignment Problem - Java | DaniWeb

To the original poster, please notify us if you cross-post the same question in any other forum. No one likes duplicating work that's already been done elsewhere, least of all a volunteer.

[Isaac93]

I'm sorry I didn't know I'm sort of new at this. Regarding the façade pattern I think it's working as it suppose to. I have a problem regarding the Key class, I don't know exactly if I have initialise a String a variable in the key superclass. The given question is shown below:
hierarchy of Keys should be developed to group all common functionality that might be used in different cipher keys. An abstract class called Key should be developed as a basis of all Cipher Keys used by the system. It should at least provide the following methods:

String toString()
boolean setValue(String) (set internal state from String parameter if value is valid)
boolean isValid(String)
String generateRandom()

Classes that might subclass Key are:
NumberKey – holding the key value as an integer. Used for Caesar and Transposition.
StringKey – which keeps the key as a String. Might also keep a Map for fast reverse
lookup while deciphering. May be used for Simple Substitution and Vigenère.

The whole Key hierarchy should be stored in a sub-package called key.