Classification of UML diagrams

As a modeling language, the definition of UML consists of UML Semantics and UML notation.
(1) UML semantic description precise metadata model definition based on UML. The meta-model provides simple, consistent, and general definitions for all UML elements in terms of syntax and semantics, enabling developers to achieve semantic consistency, eliminate the impact of the best expressions that vary from person to person. In addition, UML also supports the extension definition of the metadata model.
(2) UML notation defines the notation of UML symbols, which provides a standard for System Modeling by developers or development tools using these graphical symbols and text syntax. These graphical symbols and texts express application-level models. In terms of semantics, they are examples of UML meta-models.
The important content of the standard modeling language UML can be defined by the following five types of diagrams (9 in total:
· The first type is the use case diagram, which describes the system functions from the user's perspective and points out the operators of each function.
· The second category is static digraphs, including class graphs, object graphs, and packet graphs. The class diagram describes the static structure of the class in the system. It defines not only the classes in the system, but also the relationships between classes, such as association, dependency, and aggregation. It also includes the internal structure of the class (attributes and operations of the class ). A class chart describes a static relationship that is valid throughout the lifecycle of the system. An object graph is an instance of a class graph. It uses almost the same ID as a class graph. Their difference is that the object graph shows multiple object instances of the class, rather than the actual class. An object graph is an instance of a class graph. Because the object has a lifecycle, the object graph can only exist in a certain period of time in the system. A package consists of packages or classes, indicating the relationship between the package and the package. A package chart is used to describe the layered structure of the system.
· The third type is the behavior diagram, which describes the dynamic model of the system and the interaction between the components. The status chart describes all possible states of the class object and the transfer conditions of the State when an event occurs. Generally, a status chart is a supplement to a class chart. In practice, you do not need to draw a state chart for all classes. You only need to draw a state chart for classes that have multiple states and their behaviors are affected by the external environment and change. The activity diagram describes the activities that meet the requirements of the use case and the constraints between the activities, which is conducive to identifying parallel activities.
· Interactive digraphs describes the interaction between objects. A sequence diagram shows the dynamic cooperative relationship between objects. It emphasizes the order in which messages are sent between objects and displays interactions between objects. A Sequence diagram describes the cooperative relationship between objects, the cooperation diagram is similar to the sequence diagram, indicating the dynamic cooperation relationship between objects. In addition to information exchange, the cooperation diagram also displays objects and their relationships. If time and order are emphasized, the sequence chart is used. If the relationship between upper and lower levels is emphasized, the cooperation chart is selected. These two types of graphs are called interaction graphs.
· The fifth type is the implementation graph (Implementation divisor ). Component diagram description Code The physical structure of the component and the dependency between the parts. A component may be a resource. Source code A widget, a binary widget, or an executable widget. It contains information about logical or implementation classes. A widget graph helps you analyze and understand the degree of interaction between widgets.
The configuration diagram defines the physical architecture of the software and hardware in the system. It can display the actual computers and devices (expressed by nodes) as well as the connection relationships between them, as well as the connection type and dependency between components. Place executable parts and objects inside the node to display the correspondence between the node and the executable software unit.
From the perspective of applications, when using object-oriented technology to design a system, the first is to describe the requirements; the second is to establish a static model of the system based on the requirements to construct the system structure; the third step is to describe the behavior of the system. The models created in step 1 and Step 2 are static, including the use case diagram, class diagram (including package), object diagram, component diagram, and configuration diagram, it is a static modeling mechanism of the standard modeling language UML. The model created in step 3 can be executed, or indicates the time sequence status or Interaction relationship during execution. It consists of four diagrams, including status chart, activity chart, sequence chart, and ing. It is a dynamic modeling mechanism of the standard Modeling Language (UML. Therefore, the main content of the standard modeling language UML can also be summarized into two categories: Static Modeling Mechanism and dynamic modeling mechanism.

 

Use case diagram

It consists of participants and use cases. Use Case Diagrams help capture functional requirements. This is always a good illustration for starting a project.

Component Diagram

It mainly consists of the main system components and their relationships. This means that it is an advanced Complex System View Graph. Whether in mind, on paper towels, or using UML tools, this graphic has been created for each project that has been processed.

Class Diagram

It mainly consists of classes, interfaces and their relationships. Classes and interfaces are easy to understand, but the relationship may be complicated. After you know which components are in the system, you can naturally draw a class diagram of the components.

Activity diagram

It mainly consists of activities and decisions. These charts are basically flowcharts and data flow charts, which are used to obtain regular code streams.

Collaboration Diagram

It consists of objects and messages. This graph focuses on communication between objects, similarProgramTable.

Deployment Diagram

It mainly consists of deployment elements such as servers and their relationships. This is a logical analysis of the system.

Sequence Chart

It consists of objects (with a lifeline) and call messages. The program diagram describes the sequence of calls in the system and the creation of different objects.
A Sequence Chart consists of participants, objects, object lifeline, and messages.

Status chart

It consists of status, transition, events, and actions. Status diagrams are rarely required unless the logic is very complex.