School of Information Sciences and Technology IST 311

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

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) 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? 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) ist. psu. edu

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

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

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

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

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

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

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

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

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

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

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

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

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