Hasker's SWE 2410 Final Exam Review

The Final

• Mix of short essay, multiple choice, matching, writing code, drawing diagrams
• We will provide paper for any diagrams you must draw, and you will turn that paper in (as opposed to uploading them).
• You can bring a single, 8.5 by 11" page of notes. The page can have material (notes, diagrams, etc.) on both sides, but you cannot have two pages.
• You will need to submit your page of notes. If you want a copy, you can scan it using the campus copiers or take a picture of it in advance.
• It is critical you not discuss the exam with anyone until you have heard everyone has taken the exam or the finals week is ended. This is important because some students may take the exam late due to illnesses or other conflicts, and giving them hints will hurt your grade.

Review Topics

TODO: Add list of terms to know

Unless otherwise specified below, know the following for each pattern mentioned here:

• name
• goals
• be able to draw a class model applying the pattern
• explain the pro's and con's of using the pattern
• be able to write code applying the pattern

Patterns

• Creational patterns
  • Factory Method, including static factory methods
  • Simple Factory
  • Factory Class
  • Singleton
• Structural patterns
  • Adapter
  • Composite
  • Decorator
    • You should understand the motivations behind usng the decorator pattern with Java input & output classes, but you do not need to know the names and details of the Java IO classes
  • Façade
• Behavioral patterns
  • Command
  • Observer
  • Strategy
  • Model/View/Controller (MVC), both versions
• Other patterns
  • If covered: Null Object
• Cloud patterns (more precisely, architectural patterns for the cloud)
  • FaaS/AWS Lambda
  • Pub/Sub: observer pattern with a queue
  • Competing Consumer
• Primary facts about the patterns presented by other students
  • primary goals, primary issues
  • uses of the pattern, as discussed in the presentation

Design and other topics

• Key git terminology: clone, commit, pull, push, merge
• Definition of an object
• UML Notation
  • generalization, association, multiplicities, role names, attributes, methods, abstract vs. interface
  • sequence diagrams - reading only; you won't have to write these
  • Appropriate arrows for has-a, is-a, and needs-a and when to use each arrow
• Domain objects: responsibility, identity, behavior, state
  • give an example responsibility
  • what is identity and how is it used?
• Noun/verb identification method
• Cohesion and coupling
  • Cohesion: [coincidental, logical, temporal], [procedural, communicational], [functional]
  • Coupling: [Content], [Common, Control], [Stamp, Data]
• Threads, synchronization
• Basics of Cloud Computing, particularly serverless computing
  • virtual machine
  • definition, Lambda, Endpoint, SQS, DynamoDB

Design Principles

Design Principles

• DRY: Don't Repeat Yourself
• Program to Interfaces, not Implementations
• Open-Close Principle (extend, don't modify)
• Single Responsibility Principle
• LSP: Liskov Substitution Principle
• For each, know more nuanced principle; for example, "single responsibility" is easy to remember, but somtimes you do really need two or three responsibilities

Where to go from here?

• What would be the impact of using all the patterns on every project?
• How does coupling and cohesion relate to design patterns? Design in general?
• Is this all of the patterns?
  • Consider the Bomb pattern
  • Pattern Languages of Programs (PLoP) conferences: annual discussion of patterns among researchers
• Why the focus on domain-driven design?
  • Basic structure: layers (Ch. 28 in Java Design Pattern Essentials)
  • Cost: potential performance impact

Challenge: How many patterns fit in the Garden lab?

Challenge: Going Laptop-free

• Imagine a campus where all computing resources were cloud-based, no one carried a laptop
  • Each student has an individual VM on the server set up to run Windows as if it were a laptop right in front of you
    • That is, each student has disk space allocated to them, an operating system that runs programs (as if they are run on your laptop), and a way for mouse events/key presses/display updates to go back and forth.
  • Students carry foldable keyboards, mice and connected via their phones
  • Assume each desk in each room has a screen
• Key requirements:
  • Administrative tools so automated systems can provision systems, run updates, decommission
  • Each department determine all software needed; administrative tools autoload these
  • Need strong predictive (AI) tools to determine when systems likely to be needed so have adequate server capacity
  • Need strong data privacy: all application data stored on disks (eg documents, social media history) must be encrypted using keys owned by the student alone, with the student able to allow administrative access for a period when necessary.
  • Need monitoring tools that help determine if a system has been compromised by an unauthorized user and alert the user and then staff of the issue, but the monitoring tools must respect data privacy. For example, access times by the student and data transfer amounts can be registered (but not the content of that data).
  • Set up "honeypot" systems with weaker security to assist IT in identifying systematic penetration attacks.
  • Others?
• Working in groups, identify applications of design patterns to this system
  • For each pattern, write a couple sentences describing how it would be applied and justifying its application