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Today, I will talk to you about UML modeling principles and UML composition. Many people may not know much about it. In order to let you know more, Xiaobian summarizes the following contents for you. I hope you can gain something according to this article.

1. UML modeling

1.1 Why Model

The difference between building a mansion and building a kennel is that building a kennel doesn't require design. To produce good software requires a specification of architecture, processes, and tools.

Definition of modeling: Modeling is a simplification of reality.

Goals of modeling:

1) Models help us visualize the system as it is or as we want it to be.

2) The model allows us to specify the structure and behavior of the system.

3) The model gives a template that knows how we construct the system.

4) Models document our decisions.

Modeling is to turn complex systems into small systems and solve them one by one using the principle of "break them one by one."

1.2 UML Modeling Principles

1) It's important to choose what model to create that reflects development problems that you're struggling with.

2) Models are represented at different levels of precision. You can choose the accuracy based on the role of the observation and the reason for the observation.

3) Build models to connect with reality.

4) Important systems require a separate set of models to deal with. In object-oriented software architecture, to understand the architecture of a system, you need several complementary and interlocking views: use case, design, process, implementation, and implementation views.

1.3 Object-Oriented UML Modeling

algorithmic modeling becomes difficult to maintain as requirements change or systems grow.

Object-oriented modeling uses objects and classes as its main building blocks. For example, in a three-tier structure, we can find the objects you want in the user interface layer, the middle tier, and the database layer.

2UML Introduction

2.1 overview

UML can visualize, detail, structure, and document artifacts of software-intensive systems. *** Use it for use-case driven, architecture-centric, iterative, and incremental processes.

UML is a language, it is a visual language, it is a set of graphical symbols. It can be used for detailed description. It is also a construction language that can generate code directly. Rational XDE enables bi-directional engineering from UML to C#, or C#to UML.

2.2 UML conceptual model

Learn the three elements of UML modeling: the basic building blocks of UML, the rules by which these building blocks are put together, and some common mechanisms that apply to UML as a whole.

UML consists of four things.

1) Structural things-classes, interfaces, collaboration (it is an interaction, a group of roles and other elements that work together to provide some collaborative behavior), Use cases, active classes (with at least one process or thread whose element behavior can be concurrent with the behavior of other elements), artifacts (such as COM+ and JavaBeans), nodes.

2) Behavioral Things-Interaction, State Machine (describes the sequence of states an object or interaction experiences in response to events over its lifetime).

3) Group things---package

4) Notes on things---Notes

Four relationships in UML

1) Dependency-semantic relationship between two things

2) Association---is a structural relationship, such as aggregation

3) Generalization--General/Special Relations

4) Implementation-Used in two places: between interfaces and classes and artifacts that implement them; and between use cases and collaborations that implement them.

Diagrams in UML Modeling

1) Class diagram---static state diagram of the system, class diagram containing active classes gives static process view of the system.

2) Object diagram

3) Use case diagram

4) Sequence diagram

5) Collaboration Chart

6) State diagram

7) Activity diagram---emphasize the control flow between objects

8) Component drawing

9) Implementation drawing

2.3 architecture

We describe the architecture of software-intensive systems in five interconnected views:

1) Use case diagram of the system

2) Design view of the system-static aspects are described by class diagrams and object diagrams, and dynamic aspects are described by interaction diagrams, state diagrams, and activity diagrams.

3) Process view of the system-contains threads and processes that form the concurrency and synchronization mechanisms of the system.

4) Implementation view of the system---mainly for configuration management of system release.

5) Implementation view of the system

2.4 software development lifecycle

use-case driven

Architecture-centric

Generation process---involves the management of a series of executable releases.

There are four phases in the software development lifecycle:

initial

refine

configured

Transfer.

After reading the above, do you have any further understanding of UML modeling principles and how UML is composed? If you still want to know more knowledge or related content, please pay attention to the industry information channel, thank you for your support.

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