org.hibernate.MappingException：无法确定类型：

Question

我将Hibernate用于项目中的所有CRUD操作。它不适用于一对多和多对一关系。它给了我下面的错误。org.hibernate.MappingException: Could not determine type for: java.util.List, at table: College, for columns: [org.hibernate.mapping.Column(students)]然后我又看了这个视频教程。一开始对我来说很简单。但是，我不能使其工作。现在也说org.hibernate.MappingException: Could not determine type for: java.util.List, at table: College, for columns: [org.hibernate.mapping.Column(students)]我在互联网上进行了一些搜索，有人告诉它Hibernate中的错误，有人说，通过添加@GenereatedValue可以清除此错误，但对我不起作用。College.java@Entitypublic class College {@Id@GeneratedValue(strategy=GenerationType.AUTO)private int collegeId;private String collegeName;private List<Student> students;@OneToMany(targetEntity=Student.class, mappedBy="college", fetch=FetchType.EAGER)public List<Student> getStudents() {    return students;}public void setStudents(List<Student> students) {    this.students = students;}//Other gettters & setters omitted学生.java@Entitypublic class Student {@Id@GeneratedValue(strategy=GenerationType.AUTO)private int studentId;private String studentName;private College college;@ManyToOne@JoinColumn(name="collegeId")public College getCollege() {    return college;}public void setCollege(College college) {    this.college = college;}//Other gettters & setters omittedMain.java：public class Main {private static org.hibernate.SessionFactory sessionFactory;  public static SessionFactory getSessionFactory() {    if (sessionFactory == null) {      initSessionFactory();    }    return sessionFactory;  }  private static synchronized void initSessionFactory() {    sessionFactory = new AnnotationConfiguration().configure().buildSessionFactory();  }

Answer 1

您正在使用字段访问策略（由@Id注释确定）。将任何与JPA相关的注释放在每个字段的上方，而不是getter属性的上方

@OneToMany(targetEntity=Student.class, mappedBy="college", fetch=FetchType.EAGER)

private List<Student> students;