STUDY OF UML

DESCRIPTION:

                       

The heart of object oriented problems solving is the construction of a model. The model abstracts the essential details of the underlying problem from its usually complicated real world. Several modeling tools are wrapped under the heading of the UML, which stands for unified modeling languages. The purpose of this course is to important highlights of the UML.

            At the center of the UML are its nine kinds of modeling’s diagrams, which we described here:

§  Use case diagram

§  Class diagram

§  Sequence diagram

§  Collaborations diagram        

§  Activity diagram

§  Component diagram

Some of the sections of this course contain links to pages with more detailed information. And every section has short question. Use them to test your understanding of the section topic.

WHY IS UML IMPORTANT?

                  

 Let’s look at this question from the point of view of the constructor trade. Architects design buildings. Builders use the design to create buildings the more critical the communication between the builders and architect. Blueprints are the standard graphics languages the both builder and architect must learn as part of their trade.

            Writing software is not unlike constructing a buildings .The more complicated the underlying system, the more critical the communication among everyone involved in created and developing the software .In the past decade, the UML has emerged as the software blueprint languages for analysis, designers. And programmers a like. It is now part of the software trade. The UML gives everyone from business analysts to designer to programmers, a common vocabulary to talk about software design.

               The UML is applicable to object to object oriented problems solving. Anyone interesting in learning UML must be familiar with the underlying of object oriented problem solving it all begins with construction of a model .A model is an abstraction of the underlying problem.

         The domain is the actual word from which the problem comes. Models consist of objects that interact by sending each other message. Think of an object as alive object have thing they know (attributes) and things they can do (behaviors or operation).  

 The values of an objects attributes determines its states.

           Classes are the blueprint for object. A class wraps attributes (data) and behaviors (methods of function) into a single distinct entity objects are instances of classes.

USECASE DIAGRAM:

                

Start->programs->rational software ->rational rose enterprise edition->use case view->new->use case diagram.

            Use case diagram describes what a system does from the standpoint of a external observer. The emphasis is and a system does rather than now.

           Use case diagram are closely connected to a scenarios. A scenario is an example of what happens for a medicals clinic.

               A patient calls the clinic to make an appointment for a yearly checkup. The receptionist finds the nearest empty time slot in the appointment back and schedules the appointment for the timeslot.

         A use case is a summary of scenarios for a single task or goal .An actor is who or what initiates the events involved in that task. Actors are simply roles that people or object pay. The picture below is a make appointment use case for the medical clinic. The actor is a patient. The connection between actor and use case is a communication association.

                   Actor is stick figure .Use cases communication are lines that link actors to the use case.

                     A use case diagram is a collector of actors, use cases and their communication. We have put make appointment as the part of the diagram with four actors, use case diagram are helpful in three areas.

DETERMINING FEATURES:

          New use case of the generate new requirements as the system analyzed and the design takes place.

COMMUNICATION WITH CLIENTS:

          Their rational simplicity makes use case diagram a good way for developers to communicate with each other.

GENERATING TEST CASES:

          The collection of scenario for a use case may suggest a suit of list case for those scenarios.

CLASS DIAGRAMS:

         

            Start à Program àRational S/W àRational Rose enterprise editionàUse case View àNew à Class Diagram.

            A Class diagram gives an overview of a System by showing its classes and the relationships among display what interact but not what happens when they do interacts.

           

The class diagram below models is a customer order from a retail catalog.

            UML Class notations is a Rectangle divided into three parts

                                                * Class name

                                                * Attributes

                                                * Operation

            Names of abstracts classes such as a payment are in italics. Relationship b/w the classes are the connecting links.

            Our class diagram has three kinds of relationship.

            Association relationship b/w instances of the two classes must know about the other in order to perform its work in a diagram an association is a link connecting two classes.

            Aggregation an association in one classes belongs to the past containing the whole. In our diagram, order has a collection of order details.

            Generalization an inheritance link indicating one class in a super class of the other. A generalization has a triangle pointing to the super class payment is a super class check and credit.

            An order details can be about its item, but not the other way around the arrow also lets you know who “owns” the association’s details has an item. Association with no navigability arrows are bidirectional.

            The multiplicity of an association end is the number of possible instance of the class associated with the single instance of the other end.

SEQUENCE DIAGRAM:

       

          Start àProgram àRational S/W àRational Rose enterprise edition à Use case view àNew à Sequence diagram.

            Class and objects diagram are static model views interaction.

            Each vertical dotted line is a life link, representing the line that an object exists.

            Each arrow is a message call. An arrow goes from the sender to the top of the activation has of message on the lifeline.

            The activation bar represent the duration of the messages.

COLLABARATION DIAGRAM:

         

          Collaboration diagram are also interaction diagram. They convey the same information as a sequence diagram, they rows on object rules instead of the times that message are sent in a sequence diagram, object roles are the vertices and message are the connecting links.

ACTIVITY DIAGRAM:

          Start à Program à Rational S/W à Rational Rose enterprise edition à Use case view à new à activity diagram.

            An activity diagram is essentially a fancy flowchart. Activity diagram and state chart diagram focuses on an object undergoing, on the flow of activities involved in a single process. The activity diagram shows the how those activities depends on the another for our example are used the following process.

            The three involved classes of the activity are customer. ATM and bank. The process begins at the block state at the top and end at the concentric stop circles at the bottom. The activities are rounded rectangle.

COMPONENT AND DEPLOYMENT DIAGRAM:

          Start à Program à Rational S/W à Rational Rose enterprise edition à component.

            A component is code module component diagrams are physical of class diagram.

           

            Start à Program à Rational Rose enterprise edition à deployment view.

            Deployment diagram shows that the physical configuration of s/w and h/w. the following deployment diagram and component diagram shows the relationship among s/w and h/w components involved in library.

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