3 Replies Latest reply on Sep 2, 2007 10:53 PM by Marc de kwant

    Hibernate/spring and do I really need value objects

    jlawmi
      I have an existing spring/hibernate application which uses struts that I would like to convert to flex. I can call my remote services ok, but the flex serializer seems to want to traverse all objects returned. Since our service layer returns native hibernate objects that are disconnected, flex causes lazyinitializationexception as it traverses every getSomeCollection on our objects. Is there some way to tell the serializer to NOT do this? I am trying to avoid making wrappers or VO objects for these
      existing services.

      Thanks!
        • 1. Re: Hibernate/spring and do I really need value objects
          Marc de kwant
          Hi,

          i have as of yet not seen the possibility to restrict the flex serializer to do what you want. But i would not advice you to propagate your domain objects beyond the sevicelayer. This will only add more complexity in your presentation layer (you might want to combine multiple domain objects to a single presentation), furthermore this exposure of your domain objects can lead to weird behaviour in your domain when you, by mistake, alter the objects along the way.

          kind regards,

          Marc
          • 2. Re: Hibernate/spring and do I really need value objects
            jus74
            quote:

            Originally posted by: jlawmi
            I have an existing spring/hibernate application which uses struts that I would like to convert to flex. I can call my remote services ok, but the flex serializer seems to want to traverse all objects returned. Since our service layer returns native hibernate objects that are disconnected, flex causes lazyinitializationexception as it traverses every getSomeCollection on our objects. Is there some way to tell the serializer to NOT do this? I am trying to avoid making wrappers or VO objects for these
            existing services.

            Thanks!


            this is a common hibernate issue. i use DTO's to get around this.
            • 3. Re: Hibernate/spring and do I really need value objects
              Marc de kwant Level 1
              hi,

              As jus74 said it is common behaviour, but not only for hibernate, but also for all similar techniques (JDO, EJB3, Toplink etc). In my opinion you should model your VO/DTO objects according to the needs of your interface (i.e. the fields you need in your interface should be present in your Vo/DTO).
              Then you can choose to code custom classes to convert your VO's to your domain objects, or you can make a sightly bigger effort and create a small framework that does the translation from VO to domainobjects for your. i can verify for you that the latter will save you much time in your current project and in your future projects.

              kind regards,

              Marc