Question

我正在编写看起来像Google Latitude的代码（找到用户）。我在tomcat 6.0.33下，使用jpa / hibernate和easybeans 1.1

他们独立工作，但当我尝试链接他们时，它失败了：

Caused by: javax.persistence.PersistenceException: [PersistenceUnit: entity] Unable to build EntityManagerFactory
Caused by: org.hibernate.HibernateException: Unable to instantiate default tuplizer [org.hibernate.tuple.entity.PojoEntityTuplizer]

以下是代码：

public class Personne{
 @ManyToOne(fetch=FetchType.EAGER, cascade={ CascadeType.PERSIST,CascadeType.MERGE })
 public Personne getOwner() {
   return owner;
  }
}

public class MaPosition{
 @OneToMany
 public List<Personne> getFriends() {
   return friends;
  }
}

感谢您的帮助;）

Answer 1

如果将mappedBy添加到OneToMany，它是否有效？

public class MaPosition{
    @OneToMany(mappedBy="owner")
    public List<Personne> getFriends() {
        return friends;
    }
}

Answer 2

JPA / Hibernate OneToMany＆amp; ManyToOne为班级人员和人员地址注释。所以一个人可以有很多地址.....我用过它就有用......

一对多......

public class Person{
@OneToMany(mappedBy="person", targetEntity=Address.class, cascade=CascadeType.MERGE)
private Set<Address> addressList = HashSet<Address>();
//Getters and Setters.....
}

多对一......

public class Address{
@ManyToOne
@JoinColumn(name="PERSON_ID")
private Person person;
//Getters and Setters.....
}

JPA / Hibernate OneToMany＆amp; ManyToOne注释

2 个答案: