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Posted to users@jackrabbit.apache.org by Gonzalo Aguilar Delgado <ga...@aguilardelgado.com> on 2010/07/09 21:07:55 UTC
Why lazy initialization of collections only works second time it's
accessed?
Hi there!
This one is good! ;D
I have nodetypes as follows:
Hierarchy:
CMSObject
Hierarchy
Page
Fragment
We only create nodes of type Page and Fragment and a page can contain
several fragments because hierarchy node specifies that one or more
CMSObjects can be children of nodes of it. And of course nodes that
extends it.
Well I can save a page with it's fragments. That works well. just adding
them as childrens. That's great!
And I can retrieve the page also! Normal eh? But not! This piece of code
fails:
Page page = pageManager.getPage("/test002.psml");
System.out.println("This is page " + page.getId());
// Temp test
JetspeedPageImpl jspage = (JetspeedPageImpl) page;
---->>> Here it fails: Because proxy inside the collection
for(Iterator<JetspeedCMSObject> it = jspage.getChildren().iterator();
it.hasNext(); )
{
JetspeedFragmentImpl child = (JetspeedFragmentImpl) it.next();
if(child instanceof JetspeedFragmentImpl)
{
System.out.println("Is Fragment: " + child.getId());
}
}
And it fails because the proxy fails to load childrens on first try.
Don't know why because of log problem I have (I have open another
thread).
SEE DEBUG BELOW
Curious thing is that it tries to load two times the fragment inside the
page. One as page and one as fragment. (Check last two lines of first
try).
When I stop to debug before that point I can use the watch window in
eclipse and click on the proxy that fills the collection. This causes it
to try loading. It shows same error. But if I try a second time it
shows. Last line with:
"Target loaded".
So it works! But only the second time.
Mmmmmmmmm. Strange...
Any help on this?
Thank you in advance.
========================= NOTICE (UPDATE)===================
I added a try like this before the sentence that fails:
List<JetspeedCMSObject> child = jspage.getChildren();
try
{
child.iterator();
}catch(Exception ex)
{
log.debug("Exception occurred: " + ex.getMessage());
}
And found a error like this one:
DEBUG
org.apache.jetspeed.page.TestJackrabbitPageManager.testBasicGetPage(TestJackrabbitPageManager.java:216): Exception occurred: Cannot set the field parentFolder in the class : org.apache.jetspeed.om.model.JetspeedFragmentImpl; nested exception is java.lang.IllegalArgumentException: Cannot invoke org.apache.jetspeed.om.model.JetspeedCMSObjectImpl.setParentFolder on bean class 'class org.apache.jetspeed.om.model.JetspeedFragmentImpl' - argument type mismatch - had objects of type "org.apache.jetspeed.om.model.JetspeedPageImpl" but expected signature "org.apache.jetspeed.om.model.interfaces.JetspeedFolder"
But why the second time it works?! With this try and catch everything
works well...
===========================================================
============================================ LOG =================
DEBUG
org.apache.jackrabbit.ocm.manager.objectconverter.impl.SimpleFieldsHelper.retrieveSimpleField(SimpleFieldsHelper.java:184): retrieveSimpleField: Use default value from property definition for missing mapped property j2:name of class 'org.apache.jetspeed.om.model.JetspeedPageImpl'
DEBUG
org.apache.jackrabbit.ocm.manager.collectionconverter.impl.NTCollectionConverterImpl.doGetCollection(NTCollectionConverterImpl.java:230): Collection node found : /test002.psml/P-129b887435c-10000
DEBUG
org.apache.jackrabbit.ocm.manager.objectconverter.impl.SimpleFieldsHelper.retrieveSimpleField(SimpleFieldsHelper.java:184): retrieveSimpleField: Use default value from property definition for missing mapped property j2:title of class 'org.apache.jetspeed.om.model.JetspeedFragmentImpl'
DEBUG
org.apache.jackrabbit.ocm.manager.objectconverter.impl.SimpleFieldsHelper.retrieveSimpleField(SimpleFieldsHelper.java:184): retrieveSimpleField: Use default value from property definition for missing mapped property j2:name of class 'org.apache.jetspeed.om.model.JetspeedFragmentImpl'
DEBUG
org.apache.jackrabbit.ocm.manager.objectconverter.impl.SimpleFieldsHelper.retrieveSimpleField(SimpleFieldsHelper.java:184): retrieveSimpleField: Use default value from property definition for missing mapped property j2:name of class 'org.apache.jetspeed.om.model.JetspeedPageImpl'
============= SECOND TRY WITH eclipse debugging after this it works.
DEBUG
org.apache.jackrabbit.ocm.manager.collectionconverter.impl.NTCollectionConverterImpl.doGetCollection(NTCollectionConverterImpl.java:230): Collection node found : /test002.psml/P-129b887435c-10000
DEBUG
org.apache.jackrabbit.ocm.manager.objectconverter.impl.AbstractLazyLoader.getTarget(AbstractLazyLoader.java:59): Target loaded
Re: Why lazy initialization of collections only works second time
it's accessed?
Posted by Gonzalo Aguilar Delgado <ga...@aguilardelgado.com>.
Really curious...
Changing the line
@Bean(converter=ParentBeanConverterImpl.class) protected
JetspeedFolder parentFolder;
to
@Bean(converter=ParentBeanConverterImpl.class) protected
JetspeedCMSObject parentFolder;
Worked well because all parent objects will be of type
JetspeedCMSObject. This is not really what I want but I have to move on
and later set constraints...
But as I said. I'm still curious. Why second time trying loading worked?
El vie, 09-07-2010 a las 21:07 +0200, Gonzalo Aguilar Delgado escribió:
> Hi there!
>
> This one is good! ;D
> I have nodetypes as follows:
>
> Hierarchy:
>
> CMSObject
> Hierarchy
> Page
> Fragment
>
> We only create nodes of type Page and Fragment and a page can contain
> several fragments because hierarchy node specifies that one or more
> CMSObjects can be children of nodes of it. And of course nodes that
> extends it.
>
> Well I can save a page with it's fragments. That works well. just adding
> them as childrens. That's great!
>
> And I can retrieve the page also! Normal eh? But not! This piece of code
> fails:
> Page page = pageManager.getPage("/test002.psml");
> System.out.println("This is page " + page.getId());
>
> // Temp test
> JetspeedPageImpl jspage = (JetspeedPageImpl) page;
>
> ---->>> Here it fails: Because proxy inside the collection
> for(Iterator<JetspeedCMSObject> it = jspage.getChildren().iterator();
> it.hasNext(); )
> {
> JetspeedFragmentImpl child = (JetspeedFragmentImpl) it.next();
> if(child instanceof JetspeedFragmentImpl)
> {
> System.out.println("Is Fragment: " + child.getId());
> }
> }
>
> And it fails because the proxy fails to load childrens on first try.
> Don't know why because of log problem I have (I have open another
> thread).
> SEE DEBUG BELOW
>
> Curious thing is that it tries to load two times the fragment inside the
> page. One as page and one as fragment. (Check last two lines of first
> try).
>
> When I stop to debug before that point I can use the watch window in
> eclipse and click on the proxy that fills the collection. This causes it
> to try loading. It shows same error. But if I try a second time it
> shows. Last line with:
> "Target loaded".
>
> So it works! But only the second time.
>
> Mmmmmmmmm. Strange...
>
> Any help on this?
>
> Thank you in advance.
> ========================= NOTICE (UPDATE)===================
> I added a try like this before the sentence that fails:
> List<JetspeedCMSObject> child = jspage.getChildren();
> try
> {
> child.iterator();
> }catch(Exception ex)
> {
> log.debug("Exception occurred: " + ex.getMessage());
> }
>
> And found a error like this one:
>
> DEBUG
> org.apache.jetspeed.page.TestJackrabbitPageManager.testBasicGetPage(TestJackrabbitPageManager.java:216): Exception occurred: Cannot set the field parentFolder in the class : org.apache.jetspeed.om.model.JetspeedFragmentImpl; nested exception is java.lang.IllegalArgumentException: Cannot invoke org.apache.jetspeed.om.model.JetspeedCMSObjectImpl.setParentFolder on bean class 'class org.apache.jetspeed.om.model.JetspeedFragmentImpl' - argument type mismatch - had objects of type "org.apache.jetspeed.om.model.JetspeedPageImpl" but expected signature "org.apache.jetspeed.om.model.interfaces.JetspeedFolder"
>
> But why the second time it works?! With this try and catch everything
> works well...
>
> ===========================================================
>
>
> ============================================ LOG =================
>
>
> DEBUG
> org.apache.jackrabbit.ocm.manager.objectconverter.impl.SimpleFieldsHelper.retrieveSimpleField(SimpleFieldsHelper.java:184): retrieveSimpleField: Use default value from property definition for missing mapped property j2:name of class 'org.apache.jetspeed.om.model.JetspeedPageImpl'
> DEBUG
> org.apache.jackrabbit.ocm.manager.collectionconverter.impl.NTCollectionConverterImpl.doGetCollection(NTCollectionConverterImpl.java:230): Collection node found : /test002.psml/P-129b887435c-10000
> DEBUG
> org.apache.jackrabbit.ocm.manager.objectconverter.impl.SimpleFieldsHelper.retrieveSimpleField(SimpleFieldsHelper.java:184): retrieveSimpleField: Use default value from property definition for missing mapped property j2:title of class 'org.apache.jetspeed.om.model.JetspeedFragmentImpl'
> DEBUG
> org.apache.jackrabbit.ocm.manager.objectconverter.impl.SimpleFieldsHelper.retrieveSimpleField(SimpleFieldsHelper.java:184): retrieveSimpleField: Use default value from property definition for missing mapped property j2:name of class 'org.apache.jetspeed.om.model.JetspeedFragmentImpl'
> DEBUG
> org.apache.jackrabbit.ocm.manager.objectconverter.impl.SimpleFieldsHelper.retrieveSimpleField(SimpleFieldsHelper.java:184): retrieveSimpleField: Use default value from property definition for missing mapped property j2:name of class 'org.apache.jetspeed.om.model.JetspeedPageImpl'
>
> ============= SECOND TRY WITH eclipse debugging after this it works.
> DEBUG
> org.apache.jackrabbit.ocm.manager.collectionconverter.impl.NTCollectionConverterImpl.doGetCollection(NTCollectionConverterImpl.java:230): Collection node found : /test002.psml/P-129b887435c-10000
> DEBUG
> org.apache.jackrabbit.ocm.manager.objectconverter.impl.AbstractLazyLoader.getTarget(AbstractLazyLoader.java:59): Target loaded
>
>
>
>
>
>
>
>