Ontologies Reasoning Components Agents Simulations Structural Modeling with UML2 Jacques Robin

Outline  UML2 x UML1  UML2 meta-model package structure  UML2 Diagrams  Classes  Associations  Objects and links  Interfaces  Ports and components  Packages  Templates  Active classes, objects and parts

UML2: What is new?  New purposes:  Model-driven development  Whole life-cycle component based development  Real-time systems engineering  Fully refined modeling with semi-formal notation (OCL)  New diagrams:  Component diagram  Composite structure diagram  Timing diagram  New design:  Separates:  Abstract syntax, a MOF meta-model  Visual syntax, the Diagram Interchange (DI) standard  Semantics  Decomposes each part for reuse in a hierarchy of MOF packages linked by embedding and merge relationships

UML2: New uses  UML2 is so comprehensive that it can be used for new purposes not initially envisioned by OMG  Agent-oriented software engineering and intelligent system development  Engineering semantic web ontologies and services  Teaching course in any field through modeling and meta-modeling the presented concepts to visually and precisely structure them

UML2: Internal Structure Over 30 Sub-packages defining: Classifiers (Classes, Interfaces, etc.) Types Associations Packages Properties Constraints UML2 Infrastructure Over 50 Sub-packages defining: Components Composite structures Deployments Common behaviors (Times, Durations, Events, Signals, etc.) Actions Activities Interactions State machines Use cases Profiles Templates UML2 Superstructure 6 Sub-packages defining: Types Expressions Type value semantic domains Expression evaluation semantic do mains Type value semantic mapping Expression value semantic mapping OCL2 Defines diagrams’ visual layout Diagram Interchange MOF2 EMOFCMOF merge UML2 merge

UML2: Internal Structure UML2 Superstructure Structure Classes CompositeStuctures Components Deployments Behavior CommonBehaviors Activities Actions InteractionsStateMachinesUseCases Supplement AuxiliaryConstructs Profiles

UML2 Diagrams RequirementsAnalysisDesignTestingDeployment Structural Modeling Class (OCL) Object Component (OCL) Class Object Composite structure Class Object Composite structure Component Class (OCL) Object Component (OCL) Deployment Behavioral Modeling Use-case Activity Protocol state machine Activity State machine  Behavioral  Protocol Interaction  Sequence  Communication  Interaction overview Timing Activity State machine  Behavioral  Protocol Interaction  Sequence  Communication  Interaction overview Timing Use-case Timing

Simplified MOF Meta-Model of itself InstanceSpecification Parameter * Generalization * Association Class AssociationClass DataType PrimitiveType Enumeration Interface * 1..* Relationship NamedElement Constraint * TypedElement TypeProperty ValueSpecification Classifier FeatureClassifierRedefinableElement * Element * NamedElement BehaviorallFeature StructuralFeature Operation *

Classes: Attributes  Common characteristics of the class members  Fields:  Base or derived (isDerived)  Visibility (public, protected, private, package)  Name  Type (Primitive Built-In or Used-Defined Enumerations)  Initial default value  Properties:  isReadOnly  Object attributes: different value for each object  Class attributes: same value for all objects  Attributes for MDA: as many fields as possible!

Classes: Operations  Common signature of services provided by the class members  Fields:  Visibility  Name  Return type  Properties: isQuery, isOrdered, isUnique  Input parameter  Direction  Name  Type  Multiplicity  Default value  Properties  Object operations: called on objects  Class operations: called to manipulate class attributes  Operations for MDA: as many fields as possible!

Associations  Association:  Generic relation between N classifiers  Fields:  One or two Names  Navigation direction  Two Ends, each with:  One Multiplicity Range (default = 1)  Zero to One role  Zero to one Qualifier  Qualifier: needed to distinguish different instances of a one-to- many or many-to-many association  Navigation:  Role if present  Otherwise destination class name  Associations for MDA: as many fields as possible!

Association Classes  Class connected to an association and not to any of its ends  Allows associating properties and behaviors to an association  One object of the association class for each link of the connected association  A one-to-many or many-to-many association class cannot be substituted by a simple class and a pair of simple associations  Example:  Ca has objects A1, A2, A3, A4  Cb has objects B1, B2, B3, B4  Extent of association class Cc between Ca and Cb with * multiplicity at both ends has necessarily 16 instances  Class Cc associated to Ca through association Aca and to Cb through association Acb could have only 4 instances Elevator control QueueElevator Difference with: ? 4

N-ary Associations  Single association between N classes  Different from N-1 binary associations  Example:  Ca has objects A1, A2  Cb has objects B1, B2  Cc has objects C1, C2  No link in the ternary association Ca-Cb-Cc corresponding to pair of links A1-B1, B2-C1

Aggregation Associations  Association with “part-whole” semantics  Associate composite class to its building blocks  Static, definitional characteristic of the “whole” class  In contrast to composite structure diagrams that model dynamic, configuration characteristic of the containing class  Shared aggregation:  Many-to-many aggregation

Composition Associations  Special case of one-to-one or one-to-many aggregation where part(s) cannot exist(s) without the unique whole  Deletion of the whole must therefore always be followed by automatic deletion of the parts

Class generalizations  Taxonomic relation between a class and one of its more general direct super-class  Special case of generalization between any two classifiers  Several generalizations form a taxonomic tree free of generalization cycles  Sub-classifier inherits the features from all its direct super-classifiers  Private attributes and operations not accessible from sub-classes  Protected attributes and operations accessible from sub-classes but not from associated classes  UML generalizations allow multiple inheritance and overriding  Instances of a sub-class must satisfy all the constraints on all its super-classes (principle of substituability)

Abstract Classes  Class that cannot be instantiated  Only purpose: factor gradual refinements of common and distinct structures and behaviors down a taxonomic hierarchy  Abstract operation: common signatures of distinct implementations specified in subclasses  Supports polymorphism: generic call signature to distinct operations, with automatic dispatch to the implementation appropriate to each specific call instance

Generalization Sets  Subclass set that can be labeled as:  complete or incomplete  overlapping or disjoint  Complete and disjoint generalization sets form a partition of the super-class  Sub-subclass can specialize members of two overlapping generalization sets

Power Types  Generalization set of a super-class defined in terms of a class associated to it  Subclasses of each power type inherits features from the associated class of the super-class that defines the power type  Allows separation of orthogonal concerns  Useful for MDA as a rich modeling element

Derived Attributes, Classes and Associations  Some class diagram elements can be entirely derived from other primitive ones  Derivation rules provided in { } near the derived element or as OCL constraint  Explicit derivable information key and rules for it are key for MDA

Constrained Associations  Properties and special graphical notation can express a limited set of constraints among associations  Other constraints expressed in OCL  Constraints key for MDA

Objects and Links  Object Diagram contains:  Specific (named) or generic (named after role, unnamed) instances of classes  Possibly several instances of the same class  Specific instances of associations (links) among objects  Possibly several instances of the same association  Illustrates specific instantiation patterns of associated class diagram

Interfaces  Classifier allowing to insulate classes, packages and components from one another for plug-and-play assembly and substitution  Concrete class: attributes + operation signatures + operation implementations + instantiation  Abstract class and Interface: attributes + operation signatures  But a concrete class realizes services specified in an interfaces, while it specializes the structure and behaviors whose signature they inherit from an abstract class  Other classifiers can use these services independently of how they are realized  Explicit, class-based notation more precise and thus preferred for MDA

UML 2.0 Component Meta-Model Class Component EncapsulatedClassifier StrcuturedClassifier part * required * * provided ConnectableElementConnectorEnd 2..* * Connector * Interface Classifier * Property Structural Feature Type Classifier TypedElement Association PackagableElementPort *

Ports  Feature of a classifier that links it to:  A provided interface which operations that the classifier realizes  A set of required interfaces to be provided by the deployment environment for the classifier to realize the provided interface  Fields:  Name  Multiplicity  Host classifier  Provided interface  Required interfaces

Composite Structures: Examples  Express dynamic, run-time whole-part relationships  Same class can be part of multiple wholes in multiple configurations  Different from unique, static composition aggregation

Packages  Group of elements creating a namespace  A pure design-time entity, that might not be reflected at run-time  Model element can only belong to a single package and is deleted whenever its package is deleted  Relations between packages:  Generalization  Dependencies: nesting (sub-package), import, access (private import) and merge

Packages

Package Merge  Integrate elements of two packages into a resulting “merged” package, collapsing common elements into a single one  Redundancy-free cut and paste

Templates  Partially specified class, refined by instantiation of parameters  Alternative way to define derived class  Key for parametric patterns

Active Classes, Objects and Parts  Active classes are associated to a thread  Active objects have pro- active behavior, executing an operation not invoked by any other object  Active objects execute concurrently  Active classes/objects can be composite structures, containing both active and passive classes/objects as parts  What is an agent?  An active object that is also a component instance!