System Architect study note _ Chapter 6 (I) _ serialization

Source: Internet
Author: User

UML modeling and architecture docalization

The expansion of methods greatly hinders users' use and communication.

UML makes it easy for field experts, system analysts, developers, and users with different knowledge backgrounds to communicate with each other through a unified representation.

6.1.2 evolution of the UML Architecture

UML is described by the metadata model. The metadata model is one layer in the four-layer metadata model architecture model. The other layers are the metadata-metadata model, model layer, and user object. The meta-model layer is exported from the meta-model layer.

The schema of the meta-model can be used to define the precise definitions required by a complex model. Such a complex model usually needs to be reliably stored, shared, operated, and exchanged between tools. It has the following features:

1. Define the semantic structure recursively at each layer.
2. It can be used to define heavyweight and lightweight scaling mechanisms.
3. Unify the standards of other architectures in terms of the architecture.

The UML meta-model is decomposed into three logical sub-packages: Basic Package, behavior element package, and model management package.

6.2 UML Basics

UML uses a graphical representation mechanism to portray the system analysis and design model from multiple aspects.

10 views, four types:

1. use case diagram

2. Static graphs, including class graphs, object graphs, and packet graphs.

The edges of a class graph represent the relationships between classes, including inheritance, association, dependency, and aggregation.

An object graph describes the objects that are active in the system and their relationships in a certain state or period of time.

A package consists of sub-packages and classes.

3. A behavior diagram, including an interaction diagram, a state diagram, and an activity diagram, depicts the dynamic behavior of the system from different aspects.

The interaction diagram consists of a sequence diagram and a cooperation diagram. The sequence diagram emphasizes the time sequence of message sending between objects. The cooperation diagram emphasizes the dynamic collaboration between objects.

A status chart describes the dynamic behavior of an object.

The activity diagram describes the operation sequence, which can be concurrent and synchronized, including the control flow and information flow.

4. Implementation diagram, including component diagram and deployment diagram. Describes the composition and distribution.

The deployment graph node represents the actual computer and device, and the edge represents the physical connection between nodes. It also displays the connection type and dependency between nodes.

6.2.2 use case and use case diagram

The use case diagram is also translated into use cases and pressed. In UML, use cases are represented by an elliptic, and are often named using a dynamic object structure or a subject-predicate structure.

Optional action sequences and abnormal action sequences.

A use case is a contract between various persons in the system regarding system behaviors.

The demand phase use case is the basis for the tool project scale estimation that analysts communicate with customers;
In the design phase, use cases are the main inputs for system function design;
The implementation phase use case is a document with the check type being correct.

In essence, force analysis is a function decomposition technology.

1. The participant role is not actually part of the system.

2. Relationships between use cases, including generalization, inclusion, and expansion.

Contains special dependencies.

Extension, the basic use cases must declare several "extension points", and these extension cases can only add new behaviors and meanings to these extension points.

3. use case diagram

The Modeler can add fill colors to certain graphic operators on the way. In terms of semantics, the model that uses fill colors is the same as the model that does not use fill colors.

6.2.3 interaction Diagram

Describes the behavior order of objects in the collaboration process between objects and participants.

It usually describes the behavior of a use case and displays the message passing between the object objects involved in the use case.

Sequence and collaboration graphs can be converted to each other. A single use case requires multiple sequence or collaboration diagrams.

The interaction diagram can help analysts check the user requirements described in each use case and remind analysts to add missing classes or methods.

The horizontal direction is the object dimension. Generally, the primary participant is on the leftmost and the secondary participant is on the rightmost side.

The vertical direction is the time dimension.

6.2.4 class diagram and object Diagram

Generally, the class name is a noun.

The relationships between classes include association, aggregation, combination, generalization, and dependency.

1. links are associated instances. links represent the relationship between classes, and links represent the relationship between objects.

The Association is represented by a solid line, and the role has multiple features.

The Association class describes the attributes, operations, and other information associated with the Association.

The join class uses a dotted line to connect to the join class.

The relationship between two objects of the same class. Two associated terminals, each of which has different roles.

2. Aggregation and combination

Clustering is a special form of association, the relationship between the whole and the part of the class.

The overall and partial combination have the same survival period, which is a special form of aggregation.

3. General Relations: the relationship between general elements and special elements is what is commonly referred to as the inheritance relationship.

6.2.5 status chart and activity diagram

1. Status chart

Describes the dynamic behavior of an object during its survival, the sequence of states it has experienced, and events and actions that cause state transfer.

It is one of the five diagrams of UML dynamic behavior modeling. A state machine is used to model the lifecycle of an object. A state chart is used to display the state machine, focusing on the control flow between States.

In addition to the initial and final states, there are two States: Idle and Running. keyPress, finished, and shutDown are events.

2. activity diagram

It is one of the five diagrams of UML dynamic behavior modeling, which describe the workflow and concurrent behavior of the system. The special form of a status chart. After an activity ends, it will immediately enter the next activity.

Basic concepts: Activity, swimming track, branch, branch, confluence, object stream.

1. Activity, note that the action status and activity status are differentiated,

The action state is atomic, there is no internal transfer, there is no internal activity, the time occupied can be ignored, the purpose is to execute the action, and then turn to another State.

The activity status can be broken down, and it takes some time to complete the work.

2. The swimming track is the area division in the activity diagram. Each swimming track represents a responsibility area. The swimming paths and classes do not have a one-to-one relationship.

3. The same trigger event can be switched to different activities based on different alert conditions. Each possible transfer is a branch.

4. fork and confluence. To represent the concurrent behavior in the system or object, use fork and confluence join.

5. Object stream. An object can appear in the activity diagram. The object can be used as the input and output of the activity. The object stream in the activity diagram represents the relationship between the activity and the object.

6.2.6 component Diagram

A component is a physical and replaceable part of the system that follows a set of interfaces and provides its implementation.

The component diagram shows a group of components and their relationships, including the dependencies between the compilation, connection, and execution build.

A component is an actual file of the following types:

1. Deployment and Construction
2. Work product components
3. Execution Component

The component diagram can be modeled in the following aspects:

1. model the relationship between source code files.
2. model the relationships between executable files.

6.2.7 deployment Diagram

The deployment diagram is also called the configuration diagram and implementation diagram. It displays the topology, communication path, and software components running on the computing nodes in the system.

A system model has only one deployment diagram, which is commonly used to help you understand distributed systems.

The deployment diagram is described by the architecture designer, network engineer, and system engineer.

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