|
Replies:
12
-
Last Post:
Jul 9, 2009 11:14 AM
by: ming_chan
|
|
|
|
|
|
|
Customizing marshalling
Posted:
May 22, 2006 1:23 PM
|
|
|
I'm trying to use developer-annotated classes with JAXB in conjunction with Hibernate 3. The problem I'm running into is an org.hibernate.LazyInitializationException when JAXB tries to marshal a bean contained as a reference inside another bean. Hibernate causes the reference to be to a proxy, which throws LazyInitializationException if the bean wasn't loaded from the database.
Basically, I need to call org.hibernate.Hibernate.isInitialized(obj) when marshalling and not marshal anything if isInitialized returns false. Is there a way to do this?
|
|
|
|
|
|
|
Re: Customizing marshalling
Posted:
May 30, 2006 9:31 AM
in response to: gadams00
|
|
|
This is an interesting use case. But I'm not very familiar with Hibernate, so I need your help.
I'd like you to first experiment with a local modification to JAXB runtime. If you think it works good enough, then we can talk about incorporating into the RI, then eventually to the spec if possible.
Check XMLSerializer.childAsSoleContent. This methd is called most of the time to marshal a child object. You see that it does:
if(child==null) {
handleMissingObjectError(fieldName);
} else {
Can you change it to:
if(child==null) {
handleMissingObjectError(fieldName);
} else if(!Hibernate.isInitialized(child)) {
// skip this child
} else {
and see if that achieves what you'd like to do?
|
|
|
|
|
|
|
|
|
Re: Customizing marshalling
Posted:
Jun 1, 2006 10:29 PM
in response to: kohsuke
|
|
|
I'm putting this on my todo list. I've got a large project to work on for now, but in a few days, I should be able to test this.
Adding this to the RI and/or spec would create an artificial dependency on the Hibernate API, which I think would be bad. Maybe there's some way to create a customization hook that would serve this purpose?
Greg
|
|
|
|
|
|
|
|
|
Re: Customizing marshalling
Posted:
Jun 5, 2006 10:26 PM
in response to: gadams00
|
|
|
Yes, the first thing is to find out if this can be made to work.
Then we can figure out the right way to do it. It shouldn't be difficult to define abstractions to avoid dependency.
|
|
|
|
|
|
|
|
|
Re: Customizing marshalling
Posted:
Jun 8, 2006 2:34 PM
in response to: kohsuke
|
|
|
Okay, I tried the suggested fix out and it did not work. What I needed to change was com.sun.xml.bind.v2.runtime.property.SingleElementNodeProperty.serializeBody
there's a line:
if(v!=null) {
Class vtype = v.getClass();
TagAndType tt=typeNames.get(vtype); // quick way that usually works
...
that I changed to:
if(v!=null && org.hibernate.Hibernate.isInitialized(v)) {
Class vtype = v.getClass();
TagAndType tt=typeNames.get(vtype); // quick way that usually works
...
Now the lazy-loaded proxied properties are handled as though they were null, which was what I needed.
|
|
|
|
|
|
|
|
|
Re: Customizing marshalling
Posted:
Jun 9, 2006 4:53 PM
in response to: gadams00
|
|
|
Thanks!!
If you modify serializeBody, I suspect you'd also have to change other properties for the completeness. So it's a lot of places to make changes.
What if we write a filter Accessor that does the check? Would that work?
Would it be possible for you to share this prototype work with us? I'd like to do a few experiments, too, if possible, and I have a feeling that others might chime in.
|
|
|
|
|
|
|
|
|
Re: Customizing marshalling
Posted:
Jun 12, 2006 9:19 AM
in response to: kohsuke
|
|
|
Sure, I've got the test program all zipped up. Where can I send it?
I'm not familiar with the 'filter Accessor' that you mentioned. How does that work?
|
|
|
|
|
|
|
|
|
Re: Customizing marshalling
Posted:
Jun 12, 2006 8:06 PM
in response to: gadams00
|
|
|
You can send it to me: kohsuke.kawaguchi at sun dot com
If you search the source code for the class called "Accessor", you'll find the class that the JAXB RI uses to access values from fields.
The idea is to write an Accessor that mostly delegates to another "real" Accessor. That would let you check for uninitialzed objects and return null instead, causing the JAXB marshaller to believe that there was no such value in the first place.
|
|
|
|
|
|
|
|
|
Re: Customizing marshalling
Posted:
Nov 14, 2006 2:54 PM
in response to: kohsuke
|
|
|
I could really use this functionality as well! I'm hitting the same problems, also with lazy Collections.
I don't see a way to plug in custom "Accessor" implementations in 2.1 EA? Has any work been done on this in the nightly builds?
|
|
|
|
|
|
|
|
|
Re: Customizing marshalling
Posted:
Nov 15, 2006 7:32 AM
in response to: lpurvis
|
|
|
No. We do need to add some hooks to the RI to make this happen, but that shouldn't be difficult.
Could you file an RFE for this? So that we can keep track of it?
|
|
|
|
|
|
|
|
|
Re: Customizing marshalling
Posted:
Nov 15, 2006 9:48 PM
in response to: lpurvis
|
|
|
Thanks. I saw your e-mail in the dev alias, too.
I couldn't get to it today because of releases, but will get back to you soon.
|
|
|
|
|
|
|
|
|
Re: Customizing marshalling
Posted:
Jul 9, 2009 11:14 AM
in response to: gadams00
|
|
|
Hello,
I am using Hibernate 3 in glassfish v2.1 and I ran into this same problem. In my project there are stateless session beans exposing SOAP web service interface. These SLSBs access Hibernate entities and in many cases, returns one or Collection of these entities in the web service response.
During JAXB marshaling when constructing the web service response, if a entity (the one to be returned) has related entities via a lazy load association then it throws:
org.hibernate.LazyInitializationException: could not initialize proxy - no Session
Just like the problem described here. Another twist is that the same problem was NOT there when the same project was deployed to glassfish v2.0.
Since this thread is more than 2 years old, do we have a more or less standard solution to tell JAXB how to handle the situation ?
Does anyone have any explanation on why glassfish v2.0 and v2.1 behaves so differently in this aspect ?
Thanks
|
|
|
|
|
java.net RSS
