Course
+ id: number+ name: string+ teacher: Teacher
+ constructor(): void
User
+ id: number+ name: string- password: string
+ constructor(): void+ logout(): boolean
CourseAdmin
Teacher
+ constructor(): Teacher+ logout(): boolean+ queryCourse(id: number): Course+ modifyInfo(info: Teacher): boolean+ queryStudents(): Student[]
SystemAdmin
StudentAdmin
Student
+ constructor(): void+ logout(): boolean+ selectCourse(id: number): boolean+ modifySelectedCourse(id: number): boolean+ queryCourse(id: number): Course+ modifyInfo(info: Student): boolean
