Hibernate 配置错误 - 使用注释的一对多关系

Question

我浏览了许多视频和教程，解释了如何使用注释机制在休眠中配置一对多关系。我仍然收到此错误。

错误是： org.hibernate.AnnotationException：使用@OneToMany 或@ManyToMany 定位未映射的类：bean.Professor.coursesAssigned[bean.Course] 使用@OneToMany 或@ManyToMany 定位未映射的类：bean.Professor.coursesAssigned[bean.Course]

我的课是：

教授.java

    package bean;

    import java.util.Set;

    import javax.persistence.CascadeType;
    import javax.persistence.Entity;
    import javax.persistence.FetchType;
    import javax.persistence.OneToMany;

    @Entity
    public class Professor extends User{

        @OneToMany(targetEntity = Course.class, mappedBy = "assignedProfessor", 
                cascade = CascadeType.ALL , fetch = FetchType.LAZY)
        private Set<Course> coursesAssigned;
    }

而 course.java 是：

    package bean;

    import javax.persistence.JoinColumn;
    import javax.persistence.ManyToOne;

    public class Course {

        private Integer courseId;
        private String courseName;

        @ManyToOne(targetEntity = Professor.class)
        @JoinColumn(name = "professor_join")
        private Professor assignedProfessor;
    }

Answer 1

org.hibernate.AnnotationException: 
Use of @OneToMany or @ManyToMany targeting an unmapped class: bean.Professor.coursesAssigned[bean.Course] 
Use of @OneToMany or @ManyToMany targeting an unmapped class: bean.Professor.coursesAssigned[bean.Course]

异常已经解释了原因。 @OneToMany 和 @ManyToMany 只能在其类是映射类的属性上进行注释。如果一个类被 @Entity 注释并包含在配置文件中的 <mapping class> 或 programmatically included in the Configuration 实例中，则该类被视为已映射。

所以，我相信在Course 类上标记@Entity 后异常会消失。