java - JPA[Hibernate] 延迟加载与 GWT 问题

Question

我正在尝试将延迟加载 JPA[Hibernate] 与 GWT 前端结合使用

在实体中

 @ManyToOne(targetEntity = Item.class,fetch=FetchType.LAZY)
 private Item item;

在道中

 @Transactional
 public List<Purchase> findAllPurchases() {
   return jpaTemplate.execute(new JpaCallback<List<Purchase>>(){
   public List<Purchase> doInJpa(EntityManager em)
    throws PersistenceException {
    List<Purchase> list = em.createQuery("select o from Purchase o").getResultList();
    for(Purchase p:list){
     Item item = p.getItem();
     if(item!=null)
     item.getItemName();
    }
 return list;
}

}); }

我收到此错误。

com.google.gwt.user.client.rpc.SerializationException: Type 'com.hardwarestore.vo.Item_$$_javassist_0' was not included in the set of types which can be serialized by this SerializationPolicy or its Class object could not be loaded. For security purposes, this type will not be serialized.: instance = com.hardwarestore.vo.Item@a1eaf6

Purchase 类和 Item 类都实现了 Serialized 接口(interface)。任何形式的帮助表示赞赏。谢谢。

Answer 1

或者，您可以使用DTO(数据传输对象)。只需在服务器端转换持久化对象，然后将其发送到客户端即可。