A brief 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

Visual Modeling Language standards, can be used to describe (specify), visualize (visualize), construct (construct), and record (document) software-intensive

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

UML is a graphical language that supports modelling and software system development, providing modeling and visual 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, but also can express the software design of dynamic and static letter

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

Use, help designers shorten the design time, reduce the cost of improvement, so that hardware and software segmentation is optimal.

UML is a visual modeling language used to design software blueprints. It supports the analysis, design, implementation and delivery of object-oriented systems, and 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, describes the static structure and dynamic behavior of a system, graphic representation of a typical orientation pair

like the entire structure of the system, Model the system from different angles and form different views of the system. These graphs include the following: Class diagram, which is an inheritance structure, association, group

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

UML is a modeling language, in the actual team project, and the specific software development process can be combined to better play a role.

Two What are the features of UML?

The "generality" of UML means not only that it can be used to describe the software, but also it can be used 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 means that a series of graphical symbols can be used to form multiple views (view) to express the system analysis design intuitively and clearly.

Many complex concepts in every aspect. UML is designed primarily for human reading and use, so it is semi-formalized and easy for people to

The form of solution and communication.

UML is an analytical design-specific modeling language, which is not a programming (programming) language in itself and cannot be used directly to generate executable 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 be used to represent the abstract

The logical structure and behavior of a text program written in a high-level programming language. Compared with the traditional advanced programming language, UML can more efficiently and accurately reflect the software design

The program and ideas that are really used in the "Design programs" language. In this sense, it may be useful to call UML a "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 scientific research institutions, but directly from the industry, engineering

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, and thus has a high practical 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 it is wonderful, it itself as a product is also the Oo method to design, which makes the UML with the traditional modeling language does not have

Strong semantic expression and very flexible scalability.

Three What's the use of UML?

UML is widely used, can be summarized as "description, visualization, construction, record" 4 basic functions, in business modeling, demand analysis, System design

Implementation and testing, data modeling, project management, etc. can be used as needed.

UML modeling is an effective means of building software development documents, describing the system requirements visually and documenting the software structure, which can significantly

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 be used to help business/system analysis by combining text description or markup with visual graphical symbols.

Software Architects/designers, programmers, etc., to effectively describe the static structure 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) provides support for the specification, which is independent of any programming language and development process.

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

5) Encourage the growth and prosperity of the target tools market.

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

7) Integration of existing good practice results and experience.

Five what can UML do?

UML is not a highly formalized language, and is generally not used for 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 engineering and physics

Modeling of continuous systems in the

As a language, UML is only a form of expression, not a modeling method, in the actual development of software projects only a set of standard graphic characters

number is far from enough. Using good UML first need to master the basic principles and methods of Ooad, and in a 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 essential 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: such as internal logical structure, a variety of implicit dependencies, runtime

state change and special behavior, and so on. Written code is only an implementation, it is difficult to reflect the real nature behind the phenomenon - design, so for

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

Visual modeling has always been a successful engineering 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 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. The design of programming code to express, discuss, evaluate , and select complex software is often clumsy, and this expression is only available 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 specific platform APIs,

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

--Analysis and design. As the de facto standard and the main expression medium of OO modeling language, UML can play a key role in these occasions. So

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

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 basic building blocks: things, relationships, and graphs.

(1) Things

Things are abstractions of the most representative components of a model, including structural things, behavioral things, grouped things, and annotated 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);

Annotate things: Annotations (note).

(2) Relationship

Relationships are used to combine things, 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.

UML 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 describe the system from different sides. The system model combines these different aspects into a consistent whole, which facilitates the system's

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 basic structure seen.

2) UML rules

UML has semantic rules for describing things like:

(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 allows others to use or see the name.

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

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

3) UML public mechanism

(1) Specification-Specifications

UML is more than just a graphical language. In fact, there is a specification behind every part of its graphical representation, which provides a

A textual description of the syntax and semantics of the building block. In other words, UML diagrams are used to visualize the system, while the UML specification describes the system's fine

Section.

(2) Adornment-Retouching

Each element in the UML notation has a basic symbol that can be added to the symbol with a variety of cosmetic details.

(3) General division-Universal Division

Class A/Object dichotomy method

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

B-interface/implementation of the Dichotomy method

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

The building blocks of UML have binary methods like interface/implementation.

(4) extension mechanism-extension mechanism

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

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