UML boundary classes, control classes, entity classes

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There are three main types of classes in UML: Boundary classes, control classes, and entity classes. The concept of introducing boundary classes, control classes, and entity classes helps analysis and designers determine the classes in the system.

Boundary classes are located at the junction of the system with the outside world, forms, reports, and classes that represent communication protocols, classes that interact directly with external devices, classes that interact directly with external systems, and so on are boundary classes. The use case diagram allows you to determine the required boundary classes, each of which must have at least one boundary class, but not each actor/use case pair to be unique to the boundary class Actor/use.

The entity class holds the information to be put into the persistent storage body. Persistent storage is a medium in which data can be stored permanently, such as databases, files, and so on. Entity classes can be found through event streams and interaction graphs. Typically, each entity class has a corresponding table in the database, and the attributes in the entity class correspond to the fields in the database table.

A control class is a class that controls the work of other classes. Each use case typically has a control class that controls the order of events in the use case, and the control class can be shared among multiple use cases. The other class does not send many messages to the control class, but rather a lot of messages from the control class.

For example, in the examination system, when the student is in the examination, the student interacts with the examination paper so that the student and the test paper are the entity class, and the examination time, the rule, the score are the boundary class; When the test is over, the test paper is submitted to the keeper of the test paper, then the paper becomes the boundary class.

UML boundary classes, control classes, entity classes