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@Entity
@Table(name = "classrooms")
public class Classroom {
    @Id
    @GeneratedValue(strategy = GenerationType.IDENTITY)
    private Long id;

    private String name;

    @ManyToMany(fetch = FetchType.LAZY, cascade = CascadeType.ALL)
    @JoinTable(name = "classroom_students",
            joinColumns = {@JoinColumn(name = "classroom_id")},
            inverseJoinColumns = {@JoinColumn(name = "student_id")})
    private List<Student> students;

    // Getters, Setters و سایر قسمت‌های مورد نیاز...
}


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@Entity
@Table(name = "students")
public class Student {
    @Id
    @GeneratedValue(strategy = GenerationType.IDENTITY)
    private Long id;

    private String name;

    @ManyToMany(mappedBy = "students")
    private List<Classroom> classrooms;

    // Getters, Setters و سایر قسمت‌های مورد نیاز...
}

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@Repository
public interface ClassroomRepository extends JpaRepository<Classroom, Long> {
}

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@Repository
public interface StudentRepository extends JpaRepository<Student, Long> {
}


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@Service
public class ClassroomService {
    private final ClassroomRepository classroomRepository;

    public ClassroomService(ClassroomRepository classroomRepository) {
        this.classroomRepository = classroomRepository;
    }

    public Classroom saveClassroom(Classroom classroom) {
        return classroomRepository.save(classroom);
    }

    public List<Classroom> getAllClassrooms() {
        return classroomRepository.findAll();
    }

    public Classroom getClassroomById(Long id) {
        return classroomRepository.findById(id)
                .orElseThrow(() -> new NotFoundException("Classroom not found with id: " + id));
    }

    public void deleteClassroom(Long id) {
        classroomRepository.deleteById(id);
    }
}


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@Service
public class StudentService {
    private final StudentRepository studentRepository;

    public StudentService(StudentRepository studentRepository) {
        this.studentRepository = studentRepository;
    }

    public Student saveStudent(Student student) {
        return studentRepository.save(student);
    }

    public List<Student> getAllStudents() {
        return studentRepository.findAll();
    }

    public Student getStudentById(Long id) {
        return studentRepository.findById(id)
                .orElseThrow(() -> new NotFoundException("Student not found with id: " + id));
    }

    public void deleteStudent(Long id) {
        studentRepository.deleteById(id);
    }
}

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