1. ist.psu.edu School of Information Sciences and Technology IST 311 – Object-Oriented Design & Software Steven Haynes IST 311 – Class 7 17 January 2006 shaynes@ist.psu.edu

2. ist.psu.edu School of Information Sciences and Technology Mid-Term Deliverables Use Case diagrams –Derived from scenarios Class diagram –Conceptual Sequence diagrams TBD –Need use cases first User Interface Design –Need use cases first Due Thursday, March 3 rd (Thursday before break)

3. ist.psu.edu School of Information Sciences and Technology Design Representations Why learn the UML? What is the purpose of design representation languages and techniques?

4. ist.psu.edu School of Information Sciences and Technology Design Representations An aid to design cognition A common language for communicating about a design (specifications) A record of the design process and its outcomes (documentation)

5. ist.psu.edu School of Information Sciences and Technology UML Diagrams, Part 1. Use Case diagram

6. ist.psu.edu School of Information Sciences and Technology UML Diagrams Use Case diagram –Identify major services provided by a system to external actors (users and other systems) Establish the boundaries of the system Identify common functionality Identify high-level alternate use scenarios –Capture requirements –Development project planning tasks –Communicate with the customer/user.

7. ist.psu.edu School of Information Sciences and Technology Use Case Diagram

8. ist.psu.edu School of Information Sciences and Technology Use Cases Actors Use Cases Include (Uses) Use Cases Extend Use Cases Annotations –Pre-conditions –Post-conditions –Constraints Don’t use actor or use case generalization

9. ist.psu.edu School of Information Sciences and Technology Guidelines for Use Cases Actors – specific user roles Human actors on left Non-human actors (systems) on right Use Cases – verb-noun phrase e.g., Verify Credit Card Include (uses) link – included use case MUST be completed for the including use case to complete Extend link – extending use case represents a variant of the extended use case

10. ist.psu.edu School of Information Sciences and Technology Guidelines for Use Cases Use cases model system interactions. Use case granularity THE big problem Use annotations (notes) freely to document your assumptions. Use cases are not data stores Use cases are not data flow diagrams

11. ist.psu.edu School of Information Sciences and Technology UML Diagrams Class diagram

12. ist.psu.edu School of Information Sciences and Technology UML Diagrams Class diagram –Identify classes Attributes Operations –Identify class relationships –Identify packages –Describe a system’s static structure

13. ist.psu.edu School of Information Sciences and Technology Class Diagram

14. ist.psu.edu School of Information Sciences and Technology UML Diagrams Sequence diagram

15. ist.psu.edu School of Information Sciences and Technology UML Diagrams Sequence diagram –Describe the sequence of steps required to realize a use case or use case scenario, which represent requirements –Describe interactions between objects/classes –Perspective is time oriented

16. ist.psu.edu School of Information Sciences and Technology Sequence Diagram

17. ist.psu.edu School of Information Sciences and Technology UML Diagrams Collaboration diagram

18. ist.psu.edu School of Information Sciences and Technology UML Diagrams Collaboration diagram –Same as Sequence diagram except… –Perspective is structural or spatial

19. ist.psu.edu School of Information Sciences and Technology Collaboration Diagram

20. ist.psu.edu School of Information Sciences and Technology Degree Audit Use Cases & Classes

21. ist.psu.edu School of Information Sciences and Technology Eclipse Tutorial

22. ist.psu.edu School of Information Sciences and Technology Assignment for Thursday This is an individual assignment. If you have not had Java it will take some time so don’t wait too late to start working. Read Raposa Chapters 1 through 3. Do problems on the next two slides. For this assignment you can use the Java SDK for the labs, as described in the book, or Eclipse. Due at the start of class Thursday, 1/19.

23. ist.psu.edu School of Information Sciences and Technology Assignment Lab 1 Write a public class called CreditCalculator and declare the main() method within the class. The value for currentCredits will be input from the command line. Command-line arguments are strings so you’ll need to convert the value of currentCredits to an integer within main(): int currentCredits = Integer.parseInteger(args[0]); * Hint Run menu:Run, then the Arguments tab Write a method to calculate creditsNeeded given the value of currentCredits. Display the result. Save, compile, and run your program. You’ll need to enter the command-line argument java CreditCalculator 62

24. ist.psu.edu School of Information Sciences and Technology Assignment Lab 2 Extend the main() method in your CreditCalculator class to calculate the number of semesters remaining given 15 credits per semester. Also, if the number of currentCredits is >= 120, output the string “You can graduate!”