A simple introduction to UML modeling Learning 1:UML Unified Modeling Language

what is UML?

Unified Modeling Language (UML, also known as the Unified Modeling Language or standard modeling language) is an international object management organization OMG

and visual modeling language standards. can be used to describe narrative (specify), visualization (visualize), structuring (construct) and documenting (document) software-intensive

the various workpieces of the type system (artifacts, also translated into products) .

UML is a graphical language supporting modelling and software system development, providing modeling and visualization support for all phases of software development, including

Requirements analysis to specifications, to construction and configuration.

UML is a standard modeling language for object-oriented software. UML because of its simple, unified characteristics, and can express the software design in the dynamic and static letter

has become the industry standard for visual modeling languages. In the development of software radio system, unified Modeling language can be in the whole design cycle

Use, help designers shorten the design time, reduce the cost of improvement, so that the best hardware and software cutting.

UML is a visual modeling language used to design software blueprints. It supports the analysis, design, implementation, and delivery of object-oriented systems. Can

For system understanding, design, browsing, maintenance and information control.

UML is not a programming language, more than a formal language.

UML is a visual object-oriented modeling language. This paper describes the static structure and dynamic behavior of a system, and graphically presents a typical orientation

like the entire structure of the system. model the system from different angles and form different views of the system. These diagrams contain: Class diagrams, which are inherited structures, associations, groups

Sing Woo aggregation , timing diagrams, collaboration diagrams, and state diagrams.

UML is a modeling language, in the actual team project, and detailed software development process to combine ability to play a better role.

Two What are the features of UML?

The "universality" of UML means not only to describe the narrative software, but also to describe the business process of the general enterprise or organization and the

Hardware, software-based complex systems (so-called software-intensive systems), and even non-software systems.

The "visibility" of UML refers to a series of graphical symbols that can be passed through UML. Compose multiple Views (view) to visualize and articulate system analysis designs

Many complex concepts in every aspect. UML is mainly designed for people's reading and use, so it uses semi-formal. Easy for people to reason

The form of solution and communication.

UML is an analytic design-specific modeling language, which is not a programming (programming) language, and is not intended to be used directly to generate operational software.

UML is a higher level of abstraction than C, C + +, Java, VB, Delphi and other high-level language of the graphic language, through which we can abstract to express

The logical structure and behavior of a text program written in a high-level programming language. Compared to traditional advanced programming languages. UML can be more efficient and accurate to reflect the software design

The program and ideas that are really used in the "Design programs" language.

In this sense, it is best to call UML the "very advanced" program

The language is counted.

UML basically does not count as a new invention. It is not the research results of scholar professors and research institutes. It comes directly from the industry, project

Summary, is the product of theoretical sublimation on the basis of induction, its core content reflects the more than 30 years of global software industry leader in software design structure collar

The best practices and successful experiences of the domain, thus having very high useful value.

The practice proves that the OO analysis design (OOAD) method can describe the real world more accurately and comprehensively than the traditional method. UML is used to express the OO concept

A language tool, and very singular, it itself as a product is the same as the Oo method to design, which makes the UML with the traditional modeling language does not have

Very strong semantic expression and very flexible scalability.

Three What's the use of UML?

UML is widely used, can be summed up as "descriptive narration, visualization, construction, record" 4 basic functions, in business modeling, demand analysis, System design

and testing, data modeling, project management and other phases of the task can be based on the need to use.

UML modeling is an effective means to establish software development documents, and through UML, it can be used to describe the requirements of the system visually and record the software composition.

The quality and readability of the document reduces the effort required to write documents.

UML is essentially a special language for system analysis and design, which can help business/system analysis by visualizing graphical symbols combined with text descriptions or tags.

Programmers, software architects/designers, program apes, and other modelers effectively describe the static and dynamic behavior of complex software (or business), including workflows (data

Flow and control flow), functional requirements, structural elements and relationships, architectural composition, design patterns, object collaboration, incident response and state changes, and more.

Four What is the goal of UML?

1) to provide users with an easy-to-use, visual modeling capabilities of the language. So that users can use the language for system development and make meaningful

Model Interchange.

2) Provide extensibility and protocol mechanisms for the core concepts of object-oriented modeling language.

3) Provide specification support, which is independent of a random programming language and development process.

4) provide a formal basis for understanding the modeling language.

5) Encourage the growth and prosperity of the object tool market.

6) Support advanced development concepts. such as artifacts, collaborations, frameworks, and patterns.

7) Integration of existing good practice results and experience.

Five what can UML do?

UML is not a highly formalized language. Generally not used in theorem proving.

UML is a general modeling language based on Oo method, not suitable for user graphical interface design, VLSI design, rule-based people

Professional fields such as work intelligence.

UML is a discrete modeling language that is suitable for modeling discrete systems consisting of software, firmware, or digital logic, and is not suitable for the field of project and physics

Modeling of continuous systems in the

itself as language. UML is a form of expression, not a modeling method. Mastering a standard set of graphic characters in real software project development

Number is far from enough.

Using good UML first need to master the basic principles and methods of ooad, and in certain software development process (such as Up/rup, XP, etc.)

Under the guidance of the use of a choice.

Six why learn and master UML?

First, UML is indispensable or necessary for most of the software development teams that currently want to further improve quality.

Why do you say that? Because

For. C + +, Java and other source code does not directly and easily reflect the design of complex programs: internal logical structure, various implied dependencies, execution

state change and special behavior, and so on. Well written code, however, is a way of realizing that it is very difficult to reflect the true nature behind the phenomenon -design, so

For most projects that are slightly more complex, the code alone is not enough.

Visual modeling has historically been a successful project practice, not unique to the software industry. The design of the software is implemented in C + +, Java

Often hidden in the minds of people, and the design is correct or not is the key to determine the quality of software, a prerequisite is to use the appropriate way to express it

come on. Programming code to express, discuss, evaluate , and select complex software is often very clumsy. The emptiness of this expression is only through a similar

Modeling of UML language to fill.

Secondly, the Oo method is the mainstream of modern software development technology. The world's most advanced software teams and individuals have long been freed from the use of detailed platform APIs,

The entanglement of individual programming language features, while placing a lot of other energies on the core elements that have a significant impact on software quality, such as requirements, architectures, design mechanisms, and patterns

--Analysis and design. UML, as the fact standard and basic expression medium of OO modeling language, can play a key role in these occasions. So.

Mastering and using UML is a basic skill required by software project engineers such as system analysts, architects/designers, and program apes.

Seven What are the elements of UML?

UML consists of 3 elements: the basic building blocks of UML, the rules governing how these building blocks are placed together, and the common machine used throughout the language.

System.

1) UML basic building blocks

UML has 3 main building blocks: things, relationships, and graphs.

(1) Things

Some of the basic graphic symbols that make up the model diagram, which represent some basic object-oriented concepts.

Things are abstractions of the most representative components of a model, including structural things, behavioral things, grouping things, and gazing at things.

Structured things: such as class, Interface (Interface), collaboration (collaboration), use Case (usecase), active Class (Activeclass), component

(Component) and nodes (node);

Behavioral things: such as interaction (Interaction), state Machine (StateMachine).

Group things: Packages (package);

Stare at something: note.

(2) Relationship

Represents the relationship between basic diagram symbols.

Relationships are used to combine things together, including dependencies, associations, generalizations, and implementation relationships.

(3) Figure

The graph gathers the related things and their relationships, and is the projection of the software system at different angles.

Graphs are connected graphs that represent the vertices of things and the relationships that represent them.

Said.

An abstract description of the system made by a particular perspective.

UML is based on the different perspectives of the system. Defines the use case diagram, Class diagram, object graph, state diagram, activity diagram, sequence diagram, collaboration diagram, Component Diagram,

9 diagrams such as deployment diagrams. These graphs are described from different side-facing systems. The system model synthesizes these different sides into a consistent population. Easy to System

Analysis and construction. Although UML and other development tools also design a number of derived views, these diagrams and other supporting documents are software development

The most important structure that is seen.

2) UML rules

It is not easy to put the building blocks of UML together in random parties. Like any language, UML has a set of rules that describe a structure

What a good model should look like.

UML is used to describe the semantic rules that describe things such as the following:

(1) naming-naming: naming things, relationships, and graphs.

(2) scope-Range: A context that gives a name to a particular meaning.

(3) visibility-Visibility : How visibility enables other people to use or see names.

(4) integrity-Integrity : How integrity things relate to each other correctly and consistently.

(5) excuse-Run : What is the meaning of running a run or simulating a dynamic model.

3) UML public mechanism

There are 4 common mechanisms in UML that are uniformly applied throughout the language.

(1)Specification-Specifications

UML is more than just a graphical language. In fact, there is a specification behind every part of its graphical notation. This specification provides a description of the configuration

A textual description of the grammar and semantics of the building blocks.

That means. UML diagrams are used to visualize the system. The specification of UML is used to describe the fine section of the narrative system .

The UML specification provides a semantic backplane. It includes all the parts of a system's models, and the parts are interconnected and maintain a

Induced by. Therefore, the UML diagram is just a simple visual projection of the backplane. Each diagram shows a specific aspect of the system.

(2)adornment-retouching

Each element in the UML notation has a basic symbol. The ability to add various cosmetic details to this symbol. For example: + on behalf of public,-generation

Table Private, #代表protect等.

Examples:

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(3) General division-Universal Division

Class A/object dichotomy method

A class is an abstraction: An object is a detailed form of this abstraction. Almost every building block of UML has the dichotomy of like class/object.

Example Examples are: Use cases and use case instances (scenarios), artifacts, and artifact instances. Nodes, node instances, and so on.

B-interface/implementation of the dichotomy method

An interface declaration can be a contract, and the implementation represents a detailed implementation of the contract, which is responsible for faithfully implementing the full semantics of the interface. Almost every

The building blocks of UML have like interfaces/implementations of this dichotomy.

Examples are: Use cases and ways to implement their collaboration, operations, and implementation.

(4)extension mechanism-extension mechanism

An extension to the UML diagram symbol. Include: stereotypes, callout values, and constraints.

Examples:

A simple introduction to UML modeling Learning 1:UML Unified Modeling Language