Todays Lecture INF 111 / CSE 121: UML Software Tools and Methods - PDF document

Today’s Lecture INF 111 / CSE 121: � UML Software Tools and Methods ● Package Diagrams ● State Transition Diagrams ● Activity Diagrams y g ● Communication Diagrams Lecture Notes for Summer Quarter, 2008 Michele Rousseau Set 8 – UML – Part 2 4 Lecture Notes 8 - UML Announcements Package Diagrams � UML Links: � What is a package ? � http://dn.codegear.com/article/31863#us ● A construct that enables you to organize model elements into groups e-case-diagram ● Classes or use cases � A package diagram is a diagram with � A package diagram is a diagram with packages and their dependencies 2 5 Lecture Notes 8 - UML Lecture Notes 8 - UML Previously in INF 111/CSE121… Why use package diagrams? � UML � Increases the level of abstraction for ● Class Diagrams complex diagrams ● Use Case Diagrams ● Sequence Diagrams � Depict a high-level overview of your requirements or architecture/design ● A collection of use case or class diagrams � To logically modularize a complex diagram � To logically modularize a complex diagram � To organize Java source code Not limited to class and use case diagrams Because diagrams can get messy 3 6 Lecture Notes 8 - UML Lecture Notes 8 - UML 1

Package Diagrams: Notation Class Diagram Example � Represented as tabbed folders � Can use visibility markers + Public - Private # Protected 7 10 Lecture Notes 8 - UML Lecture Notes 8 - UML Relationships Some Basic Tips on Packages Two Types � Use Simple, Descriptive Names � Dependencies ● Changes to one package � Use when you need to Simplify affects another Diagrams ● Import is one type that � Packages Should be Cohesive grants access ● Represented by a dashed � Avoid Cyclic Dependencies Between arrow Packages � Generalizations ● Represented with an open arrow just like in previously discussed diagrams 8 11 Lecture Notes 8 - UML Lecture Notes 8 - UML Use Case Example Types of UML Diagrams Structure . Behavior . (4 types) (6 types) � Activity diagram � Class diagrams � Use Case diagram � Object diagram � State machine diagram � Package diagram g g � Interaction diagrams � Interaction diagrams � Composite structure ● Sequence diagram diagram ● Communication diagram ● Interaction overview � Component diagram diagram � Deployment Diagram ● Timing diagram If the appropriate diagram is not part of UML use it anyways 9 12 Lecture Notes 8 - UML Lecture Notes 8 - UML 2

State Transition Diagrams State Transition EX: Digital Watch � State Transition Diagrams show the dynamic behavior of a class instance or of a whole system � State : the duration of time during which an object is doing an activity. � A state diagram is a graph in which � A state diagram is a graph in which ● nodes correspond to states and ● directed arcs correspond to transitions ● labeled with event names . When to use : Necessary for those objects whose behavior across many use cases needs to be understood 13 16 Lecture Notes 8 - UML Lecture Notes 8 - UML State Transition Diagrams Actions A short software process that executes immediately. � � An event occurs at a point in time and � A transition may trigger an action. � May be triggered on entry or exit of states (instead of labeling ● transmits information from one object to another each incoming (entry) and outgoing (exit) transition with these actions). � An action occurs in response to an event and � An event may trigger an action without leaving the state, cannot be interrupted ● i.e., without triggering exit and entry actions as a self-transition would do. � An activity is an operation with certain ty s a ope at o t ce ta act � An action may trigger events, usually in other objects. A ti t i t ll i th bj t duration that can be interrupted by another � Actions may take arguments . event � A guard is a logical condition placed before a transition that returns either a true or a false. 14 Lecture Notes 8 - 17 Lecture Notes 8 - UML State Transition Diagrams: Activities Notation � Can take “longer”, ● i.e., they are processes which last as long as an object is in State Name a certain state . � Are interruptible , � State symbol: Do/Activity ● i.e., an event causing a state transition may abort an Entry/Action activity. Exit/Action Exit/Action � May be constructed from a start and a final action. Event [Guard] / Action � Transition Symbol: 15 18 Lecture Notes 8 - UML Lecture Notes 8 - UML 3

Activity Activity Diagrams Diagram: ATM Ex. � Describe ● Procedural logic ● Business process ● Workflow � A flow chart with support for parallel behavior � Branches and Merges model the conditional behavior b h i � Branch: has a single incoming transition multiple, conditional, outgoing transitions � Merge: where conditional behavior terminates Each branch has a corresponding merge � Represented as a Diamond 19 22 Lecture Notes 8 - UML Lecture Notes 8 - UML Activity Diagram (2) Conditional Thread � Forks and Joins model parallel behavior There are some exceptions to the each fork having a corresponding join: � Fork: has a single incoming transition and multiple outgoing transitions (exhibiting parallel behavior) � Conditional Thread: A condition on � Join: synchronizes the parallel behavior y p the thread originating from the fork ● All parallel behaviors complete at the join to create an exception for the join � Represented as a thick line rule. ● If the condition is false then that condition Each Fork has generally has a corresponding is considered to be complete Join 20 23 Lecture Notes 8 - UML Lecture Notes 8 - UML Activity Conditional Thread: Example Diagram: Order Ex. 21 24 Lecture Notes 8 - UML Lecture Notes 8 - UML 4

Superstates Swimlanes � What if you need to decompose your activity diagram? � Superstates ● You can show the superstate with the internal behavior inside or internal behavior inside or ● You can show these in a parent diagram ● You can also use explicit initial and final states Adv: you can decouple the parent from the subsidiary and use it in other contexts 25 28 Lecture Notes 8 - UML Lecture Notes 8 - UML Atm Ex. Activity Diagram: Superstate 26 29 Lecture Notes 8 - UML Lecture Notes 8 - UML Partitioning an Activity Diagram When do you use Activity Diagrams? Activity diagrams tell you what is � Modeling parallel behavior happening, but how do you know who � Analyzing a use case does what? ● Trying to understand what actions need to take place (in programming – which class is ● Determine behavioral dependencies responsible for each activity) � Swimlanes: group related activities into � Understanding workflow ● Documenting the logic of a business process one column (usually organizationally) ● You must arrange your diagram into vertical zones � Describing a complicated sequential separated by lines. algorithm ● Can be difficult with complex diagrams � Dealing with multi-threaded applications ◘ In this case use non-linear zones – better than nothing 27 30 Lecture Notes 8 - UML Lecture Notes 8 - UML 5

Not so good for From Use Cases to Code � Trying to see how objects collaborate ● Use an interaction diagram for that � Trying to see how an object behaves Select a Perform Perform over its lifetime it lif ti use case Use Case Use Case Write Code (or scenario) Analysis Design ● Use a state diagram for that 31 34 Lecture Notes 8 - UML Lecture Notes 8 - UML Communication Diagrams Use Case Analysis � Used to be known as Collaboration Diagrams For each use case in an iteration… (UML 1.x) – but modified for 2.0 Create a use case realization � Show interactions between run-time elements 1. � Similar to sequence diagrams, but Supplement the Use-Case 2. ● Focus on objects roles & structure descriptions ● Sequence diagram is better at visualizing processing over time time ◘ if necessary It is an object diagram that shows message passing relationships Find Analysis Classes from Use- 3. Emphasis on the flow of messages among objects, Case Behavior rather than timing and ordering of messages Distribute Behavior to Analysis � Sequence Numbers are on arrows rather than 4. vertical order Classes 32 35 Lecture Notes 8 - UML Lecture Notes 8 - UML 1. Use-Case Realization Communication Diagrams: Ex A use-case realization is a collection of UML diagrams which together validate that we have ● the classes � Class Diagrams (static relationships) ● responsibilities ● object interactions � Interaction Diagrams (dynamic relationships) – could be Sequence or Collaboration necessary to provide the behavior in our use case process. 33 36 Lecture Notes 8 - UML Lecture Notes 8 - UML 6