问即使在使用CascadeType.Persist之后，对象也会引用未保存的瞬态实例异常

EN

@Entity
@Table(name="instructor")
public class Instructor {

    @Id
    @Column(name="id")
    @GeneratedValue(strategy=GenerationType.IDENTITY)
    private int id;

    @Column(name="first_name")
    private String firstName;

    @Column(name="last_name")
    private String lastName;

    @Column(name="email")
    private String emailID;

    @OneToOne(cascade= {CascadeType.DETACH,CascadeType.MERGE,CascadeType.PERSIST,CascadeType.REFRESH})
    @JoinColumn(name="instructor_detail_id")
    private InstructorDetail instructorDetailID;


    @OneToMany(mappedBy="instructorId",cascade={CascadeType.DETACH,CascadeType.MERGE,CascadeType.PERSIST,CascadeType.REFRESH})
    private List<Courses> courses;

}

@Entity
@Table(name="instructor_detail")
public class InstructorDetail {

    @Id
    @Column(name="id")
    @GeneratedValue(strategy=GenerationType.IDENTITY)
    private int id;

    @Column(name="youtube_channel")
    private String youtubeChannel;

    @Column(name="hobby")
    private String hobby;


    @OneToOne(mappedBy="instructorDetailID", cascade={CascadeType.DETACH,CascadeType.MERGE,CascadeType.REFRESH,CascadeType.PERSIST})
    private Instructor instructor;
}

@Entity
@Table(name="course")
public class Courses {


    @Id
    @Column(name="id")
    @GeneratedValue(strategy=GenerationType.IDENTITY)
    private int id;

    @Column(name="title")
    private String title;

    @ManyToOne(cascade={CascadeType.DETACH, CascadeType.MERGE,CascadeType.PERSIST,CascadeType.REFRESH,})
    @JoinColumn(name="instructor_id")
    private Instructor instructorId;

public class createRecordDemo {

    public static void main(String[] args) {
        //Build Session Factory
        SessionFactory factory=new Configuration().configure("hibernate.cfg.xml").addAnnotatedClass(Instructor.class)
                .addAnnotatedClass(InstructorDetail.class).addAnnotatedClass(Courses.class).buildSessionFactory();
        //get current session
        Session session= factory.getCurrentSession();

        try {
            //begin transaction
            session.beginTransaction();

            Instructor instructor= new Instructor("Chad","Darby","chadDarby@luv2Code.com");
            Instructor instructor2= new Instructor("Bharath","Thippireddy","bharath@gmail.com");
            Instructor instructor3= new Instructor("Deepali","Srivastava","deepali@gmail.com");     

            InstructorDetail instructorDetail= new InstructorDetail("luv2Code","Teaching");
            InstructorDetail insDetail2=new InstructorDetail("DS&Algo","Problem Solving");
            InstructorDetail insDetail3= new InstructorDetail("webServices","communication");


            instructor.setInstructorDetailID(instructorDetail);
            instructor2.setInstructorDetailID(insDetail2);
            instructor3.setInstructorDetailID(insDetail3);


            Courses course1= new Courses("Spring");
            Courses course2= new Courses("Hibernate");
            Courses course3= new Courses("DataStructures and Algorithm");
            Courses course4= new Courses("Web services- SOAP & REST");

            course1.setInstructorId(instructor);
            course2.setInstructorId(instructor);
            course3.setInstructorId(instructor2);
            course4.setInstructorId(instructor3);
            session.save(course1);
            session.save(course2);
            session.save(course3);
            session.save(course4);


            session.getTransaction().commit();
        } catch (Exception e) {
            System.out.println("Exception Occured"+e);
            e.printStackTrace();
        }finally {
            session.close();
            factory.close();
        }



    }

}

error-INFO: HHH000400: Using dialect: org.hibernate.dialect.MySQLDialect
Hibernate: insert into course (instructor_id, title) values (?, ?)
Hibernate: insert into course (instructor_id, title) values (?, ?)
Hibernate: insert into course (instructor_id, title) values (?, ?)
Hibernate: insert into course (instructor_id, title) values (?, ?)
Exception Occuredjava.lang.IllegalStateException: org.hibernate.TransientObjectException: object references an unsaved transient instance - save the transient instance before flushing: entity.Instructor
java.lang.IllegalStateException: org.hibernate.TransientObjectException: object references an unsaved transient instance - save the transient instance before flushing: entity.Instructor