java - Hibernate hql/criteria 结果包含集合

Question

我有两个实体:

public class Photo {
   Long id;
   String url;
   @ManyToOne
   @JoinColumn(name ="user_id")
   User user;
   // other fields and getters/setters
}

第二:

public class User {
   Long id;
   @OneToMany(mappedBy = "user")
   private Collection<Photo> photos;
   // other fields and getters/setters
}

我正在尝试获取此 DTO:

public class UserDTO {
    Long id;
    List<String> photosUrls;
}

但我找不到正确的解决方案。我写了下一个标准 - 通过登录查找带有照片的用户:

getCurrentSession().createCriteria(User.class, "user")
    .createAlias("user.photos", "photos")
    .setProjection(getUserProjection())
    .add(Restrictions.eq("user.login",login))
    .setResultTransformer(Transformers.aliasToBean(UserDTO.class))
    .list();
 // projection   
    getUserProjection() {
        return Projections.projectionList()
            .add(Projections.property("user.id"), "id")
            .add(Projections.property("photos"), "url");
    }

还尝试过 HQL:

getCurrentSession()
    .createQuery("select u.id, p.url " +
        " from User u inner join u.photos p " +
        " where u.login LIKE :login")
    .setString("login", login)
    .list();

但是返回的结果是List<Object[]>输入但我需要 List<UserDTO> .

<小时/>

更新:

HTTP Status 500 - Request processing failed; nested exception is org.springframework.orm.hibernate4.HibernateSystemException: IllegalArgumentException occurred while calling setter for property [com.memories.dto.UserDTO.photos(expected type = java.util.List)]; target = [com.memories.dto.UserDTO.photos@4e162869], property value = [https://i1.sndcdn.com/artworks-000031744302-0730nk-t500x500.jpg] setter of com.memories.dto.UserDTO.photos; nested exception is IllegalArgumentException occurred while calling setter for property [com.memories.dto.UserDTO.photos] (expected type = java.util.List)]; target = [com.memories.dto.UserDTO.photos@4e162869], property value = [https://i1.sndcdn.com/artworks-000031744302-0730nk-t500x500.jpg]

Answer 1

我认为使用上面的代码，您所要做的就是将结果直接分配给 List，它应该轻而易举地工作。像这样的东西。

List<User> userList = yourCriteria.list();