UML是什么,包括哪些内容
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发布时间：2022-10-11 15:04
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时间：2023-10-13 10:33
1、 UML -----The Unified Modeling Language is a standard language for writing software blueprints.The UML may be used to visualize, specify, construct, and document the artifacts of a software-intensive system.
2、 Stereotype-----A stereotype is an extension of the vocabulary of the UML, allowing you to create new kinds of building blocks similar to existing ones but specific to your problem.
3、 Tagged value-------A taffed value is a property of a stereotype, allowing you to create new information in an element bearing that stereotype.
4、 Component--------A component is a replaceable part of a system that conforms to and provides the realization of a set of interfaces.
5、 Message-----A message is the specification of a communication among objects that conveys information with the expectation that activity will ensure
6、 Note-----A note is a graphical symbol for rendering constraints or comments attached to an element or a collection of elements.
7、 Constraints------A constraint is a textual specification of the semantics of a UML element, allowing you to add new rules or to midify existing ones.
8、 Interaction-----An interaction is a behavior that comprises a set of messages exchanged among objects in a set of roles within a context to accomplish a purpose.
9、 Action----An action is an executable computation that results in a change in state of the model or the return of a value.
简答
1， UML中描述软件体系结构的五种视图及其内容？architecture view
@The use case view of a system encompasses the use cases that describe the behavior of the system as seen by its end users,analysts,and testers.
@The design view of a system encompasses the classes,interfaces,and collaorations that from the vocabulary of the problem and its solution.
@The interaction view of a system shows the flow of control among its various parts,including possible concurrency and synchronization mechanisems.
@The implementation view of a system encompasses the artifacts that are used to assemble and release the physical system.
@The deployment view of a system encompasses the nodes that form the system`s hardware topology on which the system executes.
2， 建模的四项基本原则？principles of modeling
*The choice of what models to create has a profound influence on how a problem is attached and how a solution is shaped.
*Every model may be expressed at different levels of precision.
*The best models are connected to reality.
*No single model or view is sufficient.Every nontrivial system is best approached through a small set of nearly independent models with multipe viewpoints.
3，如何建模系统的接缝？modeling the seams in a system
To model the seams in a system:
!!Within the collection of classes and components in your system,draw a line around those that tend to be tightly coupled relative to other sets of classes and components.
!!Refine your grouping by considering the impact of change,
. Classes or components that tend to change together should be grouped together as collaborations.
!!Consider the operations and the signals that cross these boundaries, from instances of one set of classes or components to instances of other sets of classes and components.
!!Package logically related sets of these poerations and signals as interfaces.
!!For each such collabotation in your system,identify the interfaces it requires from(imports) and those it provides to others(exports).You model the importing of interfaces by dependency relationships,and you model the exporting of interfaces by realization relationships.
!!For each such interface in your system,document its dynamics by using pre-and postcongitions for each operation, and use cases and state machines for the interfaces as a whole.
4.如何建模系统的需求？modeling the requirements of a system
To model the requirements of a system:
//Establish the context of the system by identifying the actors that surround it;
//For each actor,consider the behavior that each expects or requires the system to privide;
//Name common behaviors as use cases.
//Factor common behavior into new use cases that are used by others;factor variant behavior into new use cases that extend more main line flows.
//Model these use cases,actors,and their relationships in a use case diagram;
//Adorn these use cases with notes or constraints that assert nonfunctional;you may have to attach some of these to the whole system.
5如何利用制品图建模物理数据库？modeling a physical database by artifact diagrams
1. For simple CRUD(create, read, update,delete) operations,implement them with standard SQL or ODBC calls;
2. For more-complex behavior(such as business rules), map them to triggers or stored proceres.
Guidelines:
&Identify the classes in your model that represent your logical database schema.
&Select a strategy for mapping these classes to tables.You will also want to consider the physical distribution or your databases.Your mapping strategy will be affected by the location in which you want yout data to live on your deployed system.
&To visualize,specify,construct,and document your mapping,create an artifact diagram that contains artifacts stereotyped as tables.
&Where possible,use tools to help you transform your logical design into a physical design.
6如何对注释建模？modeling comments
*Put your comments as text in a note and place it adjacent to the element to which it refers. You can show a more explicit relationship by connecting a note to its elements using a dependency relationship.
*Remember that you can hide or make visible the elements of your model as you see fit.This means that you don`t have to which it is attached are visible.Rather,expose your comments in your diagram only insofar as you need to communicate that information in that context.
*If your comment is lengthy or involes something richer than plain text,consider putting your comment in an external document and linking or embedding that document in a note attached to your model.
*As your model evolves,keep those comments that record significant decisions that cannot be inferred from the model itself,and-unless they are of historic interest-discardthe others.
7，如何建模逻辑数据库模式？modeling a logical database schema
The UML`s class diagrams are a superset of entity-relationship(E-R) diagrams, a common modeling tool for logical database design.
To model a schema:
$Identify those classes in your model whose state must transcend the lifetime of their applications.
$Create a class diagram that contains these classes.You can difine your own set of stereotypes and tagged values to address database-specific details.
$Expand the structural details of these classes.In general,this means spencifying the details of their attributes and focusing on the associations and their multiplicities that relate these classes.
$Watch for common patterns that complicate physical database design,such as cyclic association and one-to-one associations.Where necessary,create intermediate abstractions to simplify your logical structure.
$Consider also the behavior of these classes by expanding operations that are important for data access and data integrity.In general,to provide a better sepatration of concerns,business rules concerned with the manipulation of sets of these objects should be encapsulated in a layer above these persistent classes.
$Where possible,use tools to help you transform your logical design into a physical design.
8，给出顺序图的步骤？modeling flows of control by time ordering
To model a flow of control by time dodering:
+Set the context for the interaction,whether it is a system, subsystems,operations,or class,or one scenario of a use case or collabotation;
+Set the stage for the interantion by identifying which objects play a role in the interaction.Lay then out on the sequence diagram from left to right,placing the more important objects to the left and their neighboring objects to the right;
+Set the lifeline for each object.In most cases,objects will persist through the entire interaction. For those objects that are created and destroyed ring the interaction ,set their lifelines,as appropritate,and explicitly indicate their birth and death with appropriately stereotyped messages;
+Starting with the message that initiates this interaction, lay out each subsequent message from top to bottom between the lifelines,showing each message`s properties, as necessary to explain the semantics of the interaction;
+If you need to visualize the nesting of messages or the points in time when actual computation is taking place, adorn each object`s lifeline with its focus of control;
+If you need to specify this flow of control more formally, attach pre-and postconditions to each message.
9，如何利用制品图建模可执行程序的发布？modeling an executable release
To model an executable release:
#Identify the set of artifacts you`d like to model.Typically,this will involve some or all the artifacts that live on one node,or the distribution of these sets of artifacts across all the nodes in the system.
#Consider the stereotype of each artifact in this set.For most systems you`ll find a small number of different kinds of artifacts.You can use the UNL`s extensibility mechanisms to provide visual cues for these stereotypes.
#For each artifact in this set, consider its relationship to its neighbors.Most often,this will involve interfaces that are exported by certain artifacts and then imported by others.If you want to expose the seams in your system,model these interfaces explicity.If you want your model at a higher level of abstraction, elide these relationships by showing only dependencies among the artifacts.
