UML for Global Computing Lecture 3: Property-Driven Development

Transcription

1 Contents UML for Global Comuting Lecture 3: Proerty-Driven Develoment Martin Wirsing LMU München in cooeration with Hubert Baumeister Lecture : Introducing UML for Mobility Lecture 2: Refining Mobility Designs Lecture 3: Proerty-driven Develoment of Mobile Systems Develoment rocess Case study: A Multi Dungeon Game Simle game Game with logical distribution GC Summer School, Edinburgh, July 2003 Proerty-Driven Design Joint develoment of test / secification / model Executable models Immediate feedback Automatic tests Refinement Adding details Refactoring Tools Secification: JML / OCL Tests: Fit and JUnit Modeling language: UML and Java Proerty-Driven Develoment: Process I Ste : Requirements Cature Develo Stories (functional- and non functional requirements) Define develoment strategy Examle: MUD Game Develoment Strategy for the MUD Game Requirements Multi Dungeon Game walks through rooms Meets other human- /non human layers Talks Fights Trades Functional Requirements Detail Game with Physical Distribution Game with Logical Distribution Simle Game Fighting Commun.... Played via mobile hones Distribution Client server vs. Peer to Peer Non-functional Requirements Functionality

2 Develoment Strategy for the MUD Game Proerty-Driven Develmt: Design and Imlementation Detail Game with Physical Distribution Game with Logical Distribution Game Multi- Game Handle Objects Fighting Commun.... Modelling / Programming [Develo UML Behaviour Diagrams; generate /develo imlementations of behaviour; test and refactor rograms] Use Case Develoment [Extract Class Diagram and Use Cases from Stories] Functionality Proerty Extraction [Generalize tests to invariants and re-/ostconditions in OCL; translate to JML] Scenario Develoment [Develo UML Sequence Diagrams for Use Case; generate semi-automatically tests from Sequence Diagrams] Proerty-Driven Develoment: Process II Ste 2: Design and Imlementation For each Story iterate Ste 2.: Use Case Develoment Extract Use Cases from Stories Ste 2.2 Scenario Develoment Develo UML Sequence Diagrams for Use Case Generate semi-automatically tests from Sequence Diagrams (generate test temlates for FIT or Junit and comlete temlates with test data and exected results) Ste 2.3: Proerty Extraction Generalize tests to invariants and re-/ostconditions in OCL/MTLA Translate to JML Ste 2.4: Modelling / Programming Develo UML Behaviour Diagrams (Sequence-, Activity Diagrams, and State Charts) Generate /develo imlementations of behaviors Test and refactor rograms Proerty-Driven Design: Remarks Class Diagram evolves in arallel with the stes Different tools / notations for different levels of detail High level UML Diagrams Sequence Diagrams, Activity Diagrams, State Charts, etc. FIT accetance tests OCL / MTLA logic secifications Low level Java (or for mobile agents: Jade) JUnit unit tests JML logic secifications Difference Use Case / Story Story Tells an interesting "story" about the system that is relevant to the customer Functional- / non-functional requirements Includes Use Cases; however, usually less formal than use cases Use Case Functionality of the System Defined by Pre- / Postconditions Primary- / Secondary Scenarios. Simle Game GC Summer School, Edinburgh, July 2003

3 Examle: Simle MUD-Game Story: Game The Simle MUD Game consists of the Stories: Game Multi- Game Handle Objects First iteration: Develo Game from Story Second iteration: Develo Multi- Game from Story Extract Class diagram and Use Cases Develo UML Sequence Diagrams and Accetance Tests (FIT) Find Proerties: Invariants and Pre-/Post Conditions in OCL and translate to JML Develo Imlementation (in Java) Run Accetance Tests alone and with JML assertions Start Game Rules Secial The game has several s; each contains several s which may be connected. The game starts in the Start of the lowest and ends in the highest. From the Secial the layer advances to the next or the game is over. The moves through the rooms until he finds the Secial. He can see the rooms which are directly connected with its current room. The layer moves always to a room which is directly connected to its M. Wirsing: current UML for room. Global Comuting Story: Multi Game Start 5 Secial Additional Game Rules Several layers in the game A layer can see the other layers in its room Design of Class Diagram and Use Cases Extract classes (without oerations) from Story.,,, Start, Secial Define the concetual mobility structure of the game: s and s are locations; layers are mobile objects Extract Use Cases from Story Look to connected s Move Move to next Advance to next level Class Diagram for Multi Game Use Cases for the Multi- Game MUD look room exits look look other layers Start connectedto Secial current move advance to next level move to room

4 Develoment of Scenarios and Accetance Tests SDM: Scenario for moveto Use Case Develo Sequence Diagrams for each Use Case r:start r: r2: r3: Standard behaviour (moves in black color are ossible) Forbidden behaviour (moves in red color are forbidden!) Derive Accetance Test from Sequence Diagram Create Test Temlate Move(r) Move(r) Add arameter data and exected results Extend Class Diagram by the oerations of the Accetance Test? {cannot re-enter the start room} Forbidden Move SDM: Scenario for move Use Case SDM: Scenario for move Use Case r:start r: r2: r4: r:start r: r2: r4: Move(r) Move(r) Move(r2) Move(r3) {r2 not connected to r} {r4 is connected to r} Accetance Tests with FITNesse FitNesse is a collaborative testing and documentation tool develoed by R. Martin et al. It is a Wiki imlemented in Java Test develoment: Write accetance tests in Wiki where every test is shown in a table Imlement a test fixture in Java for the oerations in the test tables Accetance Test for Move to Next Create layer Move to Forbidden: Move to 2 Forbidden: Move back to Start Move to 4

5 Derive Proerties Class Diagram for Multi- Game Extend the class diagram by the oerations of discovered in the accetance test (moveto;...) Derive OCL re- and ost conditions for the oerations Derive OCL invariants inv: layers >forall(layer layer.current = self ) inv: current!= null imlies current.layers >includes( self ) Translate OCL to JML which automatically creates assertions in the imlementation connectedto current layers Start Secial moveto(room)... re: current.connectedto >includes(room) ost: current. = room; excetion: re: not(current.connectedto > includes(room)) signals: invalidmoveexcetion; Translate OCL Pre/Post Conditons to JML ublic normal_behavior requires current().connectedto().contains(room); ensures current() == room; also ublic excetional_behavior requires!current().connectedto().contains(room); assignable \nothing; signals (InvalidMoveExcetion); ublic void moveto( room) throws InvalidMoveExcetion Translate OCL Invariants to JML ublic instance invariant (\forall layer; layers().contains(layer); layer.current() == this); ublic instance invariant current()!= null ==> current().layers().contains(this); Invariante der Klasse Invariante der Klasse Ste 2.4: Modelling / Programming Activity Diagram (RC) for.moveto(r2) Develo Activity Diagrams for moveto() Resonsibility centered : Location centered Generate and test Java imlementation Refactor, if necessary [r.connectedto->includes(r2)] [not(r.connectedto->includes(r2))] throw InvalidMoveExcetion {r2 = current} : [atloc = r] <<move>> current := r2 : [atloc = r2] add to r2 layers

6 Accetance Test for Move to Next Corrected Diagram (RC) for.moveto(r2) : throw InvalidMoveExcetion [not(r.connectedto->includes(r2))] [r.connectedto->includes(r2)] remove from r layers {r2 = current} : [atloc = r] <<move>> current := r2 : [atloc = r2] TestLookOthers shows error: Forgot to remove from the old room add to r2 layers Activity Diagram (LC):.moveTo(r2) r: {r2 = current} [not(r. connectedto->includes(r2))] throw InvalidMoveExcetion Accetance Test for Move to Next All tests are successful! [r. connectedto->includes(r2)] : remove from the layers of r <<move>> current := r2 add to the layers of r2 r2: : Accetance Test Suite Game with Logical Distribution All tests are successful! GC Summer School, Edinburgh, July 2003

7 MUD Game with Logical Distribution Refactor and extend Class Diagram Story: Play the MUD Game with mobile hones: Add server and mobile hones as locations s are located on hones For laying the game, the current room is moved to the hone with the layer s and s are mobile objects Phone Server PersonalObject inventory Proerty-driven develoment as before: Refactor and extend Class Diagram Develo Sequence Diagrams and tests Derive OCL Proerties Develo UML Activity Diagram and generate and test imlementation Refactor, if necessary Secial connecteds Start Develo SDM: set current room Unit Test with JUnit hone server: Server <<create>> moveto(hone) current(sr) sr <<clone>> sr {Start sr located at server} JUnit is an Oen Source Framework for automatising Unit-Tests for Java. Develoed by Kent Beck and Erich Gamma Test Case Design: Generate test temlate from Sequence Diagram Add assertions for the checking the current state {current room located at hone} {current room is a clone of sr} JUnit Test for set Current Proerties: Additional Invariant for ublic void testgamelocation() throws Excetion { Server server = new Server(); Phone hone = new Phone(); layer = new ("Hubert"); layer.moveto(hone); Phone Server inv: current!= null imlies current.locatedat().location() game = server.game(); asserttrue(game.start().locatedat(server)); layer.current(game.start()); Constructs clone of Start at hone connectedto current } asserttrue(layer.current().locatedat(hone)); asserttrue(layer.current().cloneof(game.start())); asserttrue(game.start().locatedat(server)); Secial Start

8 Translation to JML Activity Diagram (LC): MoveTo Method Additional Invariant of the :Phone {r2 = current} [!(r.connectedto->includes(r2))] throw InvalidMoveExcetion [r.connectedto->includes(r2)] ublic instance invariant current()!= null ==> current().locatedat(location()); :Server r2: remove from the layers of r <<clone>> Create a local coy of r2 r3: current := r3 add to the layers of r3 JUnit Test Run Story Handle Objects Story Personal objects like bananas or ales can be in a room A layer can see the objects in the current room, he can use, take or ut down an object All tests are successful! Class Diagram for Handle Object All Use Cases MUD look room exits Phone PersonalObject inventory look look objects Server look inventory look other layers connecteds move advance to next level move to room Secial Start handle object use object take object ut down object

9 Activity Diagram: TakeObjectFrom Activity Diagram (LC): TakeObjectFrom [current room contains object] add object to inventory [current room does not contain object] throw InvalidAction Excetion hone:phone hone2:phone server:server [current room does not contain object] throw InvalidAction Excetion [current room contains object] add object to inventory Remove object from Current, server, all clones of the original room current room original room [has other layer] other layer current room [all other layers notified] other layer current room [has other layer] current room [all other layers notified] original room Remove object from all clones of the original room, Current, server, MUD Game with Physical Distribution Imlement MUD Game over Platform which suorts mobility (e.g. Jade) or Use RMI and serialization of Java Problem: RMI sends remote object with all its associated objects; Remedy: Use exlicit object names to searate objects from associated objects in order to send only the actual object Summary Lecture : UML extension with mobility First aroach for exlicit modeling of mobility in UML Simle solution Used already in industry and for teaching (DEGAS-Project, SWE-Praktikum) Lecture 2: Refinement Simle syntactic refinement calculi for activity and sequence diagrams for mobility MTLA as a formal basis for a UML notion of refinement: Refinement is imlication (with ossible hiding of variables or locations)! Summary Lecture 3: Proerty-Driven Design Executable models Immediate feedback Allows to exeriment with the system Joint develoment of formal roerties and model Tests Formal secification Tests + Refactoring = "Soft"ware Future Work Test- / Verification Tool for State Charts Better Integration of Formal Methods Executable UML Model-Driven Architecture (MDA) Problems: defined translations