Title: "[[Unified-Modeling-Language]]"
Author:
- AllenYGY
status: DONE
tags:
- NOTE
- Java
- Lec1
- Program
created: 2023-11-02T00:59
updated: 2024-05-31T01:02UML
- Class diagrams
- Sequence diagrams
- Use case diagrams
- Activity diagrams
Class Diagram
-
Describe the system in terms of classes and their relationships.
-
Natural ways of reflecting the real-world entities and their relationships.
Class Relationship
Association (directional + Multiplicity)
Association represents a general binary relationship that describes an activity between two classes.
A class is aware of and holds a reference to another class.
- Bidirectional or Unidirectional
- Unidirection
- Bidirectional
Aggregation
A special type of association, which represents a “Has-A” relationship 空心菱形
- They may have different life cycles.
Composition
Represents a “Part-of” relationship. 实心菱形
- Life cycle of the part is dependent on the whole’s life cycle
Inheritance
Often referred as a “is-a” relationship. 三角空心
E.g., a dog is an animal.
Realization/Implementation
For interface
- In Java, an interface is not a class but a set of requirements for classes that want to conform to the interface
