Flashcards
Java Software Development Unit 3
Cards in this deck (33)
- 1abstract classA class which cannot be instantiated, i.e. one which has no instances
of its own but only instances of its child classes. An abstract class defines properties
which are common to its child classes. It should not be confused with a class
representing abstract entities. - 2abstract entityAn entity that has an existence, but does not correspond to a tangible
entity. For example, the film Citizen Kane is an abstract entity, while the DVD which
records the film is a tangible entity. - 3associationAn association represents the links that may exist between the objects of
two classes. These links have a common meaning, and represent a particular relationship
(connection) between these objects that is significant for the system domain. - 4attributeAn attribute is a property of an object. All objects of a class have the same
attributes. - 5candidate classA class that may be needed to model a category of real-world entities
from the system domain. - 6child classA class that is a specialisation of some other class, known as its parent
class; a subclass. - 7class (in the conceptual model)A class models a category of real-world entities from
the system domain. - 8class descriptionA formal description of a class within a conceptual model or a
structural model. - 9class diagramClass diagrams are used to show structural aspects of the system
domain and of a system at various stages in its development. As a model of the system
domain, a class diagram depicts conceptual classes and associations connecting
them. As a model of the system, a class diagram depicts the software classes that are
involved in the system and the associations connecting them. - 10conceptual modelThe model which represents the significant entities in the system
domain and the connections between them as a collection of classes and their
attributes, associations and invariants. The conceptual model of the system domain is
taken to be the initial structural model for the software system to be developed. It
consists of a class diagram, class descriptions and invariants. - 11concrete classA class that, unlike an abstract class, may have instances that are not
instances of any of its child classes. - 12constraint (on the system domain)A limitation on the entities in the system domain,
their properties and relationships. - 13derived associationAn association all of whose links can be derived using other
elements of the model. - 14derived attributeAn attribute all of whose values can be derived using other elements
of the model. - 15event (in the system domain)Any significant circumstance, episode, interaction,
happening or incident, e.g. deliveries, registrations, bookings, enrolments - 16generalisationA relationship between classes that captures the similarities and
differences between two related classes. Saying that class A is a generalisation of
class B means that the common (similar) structure and behaviour is defined by class A,
and the distinctive (different) structure and behaviour is defined by class B. It means that
an instance of class B is substitutable for an instance of class A. - 17inheritTake on the properties (attributes and associations) of a parent class.
- 18initial structural modelThe initial structural model is the conceptual model viewed as
the first model of the structure of the proposed software system. In other words, the
conceptual and initial structural models ‘look’ the same but have different perspectives:
one models the system domain; the other is taken as the first model of the software
system itself. - 19instanceRefers to a particular object of a class or a particular link of an association
- 20invariantAny condition on the objects of a conceptual model, their attribute values
and links that must hold for the requirements to be satisfied and the consistency of the
model to be guaranteed. - 21linkA link exists between two objects when there is a connection between the entities
they represent that is significant for the system domain. A link is an instance of an
association. - 22multiplicityThe multiplicity of an association with respect to one of the classes
involved defines how many objects of that class may be linked with a single object of the
other class involved in the association. - 23noun phraseA noun phrase is a phrase (a sequence of words like ‘number of copies’)
that functions as a noun and which can be used anywhere that a noun could be used. - 24object (in the conceptual model)An object models a real-world entity from the
system domain. - 25organisational unitAny part of an organisational structure to which people or things
in the system domain belong. - 26parent classA class that is a generalisation of one or more other classes known as its
child classes; a superclass. - 27roleThe particular responsibility or job that a person (thing) may perform in the system
domain, e.g. employee, student, lecturer, driver. - 28specialisationSaying that a class B is a specialisation of class A means that class A is
a generalisation of class B. - 29stereotypeA label providing additional information about some component of a UML
model. Stereotypes are enclosed in double chevrons, e.g. <>. - 30structural modelA representation of the system in terms of classes and the
relationships between them. - 31substitutable, substitutabilityObjects of a class B are substitutable for objects of a
class A if anywhere that an instance of class A is required, an instance of class B can be
used instead. For class A to be a generalisation of class B, instances of B must be
substitutable for instances of A. - 32tangible entityA physical ‘thing’ in the system domain such as an aeroplane, vehicle,
reactor or person, i.e. something that can be seen or touched. - 33value (of an attribute)Specific information that an object holds in respect of an
attribute.
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- Java Software Development Flashcards on Java Software Development Unit 3, created by nina.evangelou on 17/09/2013.
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- nina.evangelou · Sep 2013
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- Feb 19, 2016
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