Custom findStudentByEmail function will fetch student information using student email address.

Application.java

/*          FIND SOMEONE WITH GIVEN EMAIL ADDRESS
             * ==========================================================================*/
            studentRepository
                    .findStudentByEmail("[email protected]")
                    .ifPresentOrElse(
                            System.out::println,
                            ()-> System.out.println("Student with email [email protected] not found"));

StudentRepository

public interface StudentRepository extends JpaRepository<Student, Long> {

    Optional<Student> findStudentByEmail(String email);
}