[Cayenne-user] Usage in Axis2

On Jul 18, 2007, at 11:53 PM, Ajay H. Daptardar wrote:
Hello all,

I am trying to use Cayenne within Axis2. I copied the three
configuration XML files into the classes folder for Axis2:

/opt/apache-tomcat-6.0.13/webapps/axis2/WEB-INF/classes

I can create the data context object but during runtime, data
context's entity resolver cannot find the mapped class and I get the
following:

"Class is not mapped with Cayenne"

However when I run the same application as standalone, I have no
errors.

Any help much appreciated.

Best,
- Ajay

On 7/19/07, Andrus Adamchik wrote:
That is strange... I assume Cayenne jars are in "axis2/WEB-INF/lib",
and not in some shared location?

Andrus

// DataMaps can contain all kinds of garbage...
// TODO (Andrus, 10/18/2005) it would be nice
to log something
// here, but since EntityResolver is used on
the client, log4J is
// a no-go...

// TODO (Andrus, 10/18/2005) it would be nice
to log something
// here, but since EntityResolver is used on
the client, log4J is
// a no-go...

On Jul 20, 2007, at 9:15 PM, Ajay H. Daptardar wrote:

Hi Andrus,

The structure of the Axis2 archive (app.aar) is as follows:

META-INF/
META-INF/MANIFEST.MF
META-INF/services.xml
lib/
lib/bcel.jar
lib/cayenne.jar
lib/jibx-bind.jar
lib/jibx-extras.jar
lib/jibx-genbinding.jar
lib/jibx-genschema.jar
lib/jibx-run.jar
lib/mysql-connector-java-5.0.6-bin.jar
lib/qdox-1.6.1.jar
lib/stax-api.jar
lib/wstx-asl.jar
lib/xmlpull_1_1_4.jar
lib/xpp3.jar
app/<APPLICATION CLASSES>

Cayenne jar is in the application's lib folder not axis'. After
stepping through the debugger, I found out that even though the
application can load the Cayenne data context, the entity resolver,
when it PUTS object entities in the cache, it uses the name of the
entity and when it tries to GET the object entity, it tries to use the
oe.getJavaClass() which throws an exception. This is not logged and
the comment there is:

// DataMaps can contain all kinds of garbage...
// TODO (Andrus, 10/18/2005) it would be nice
to log something
// here, but since EntityResolver is used on
the client, log4J is
// a no-go...

the Util.getJavaClass() fails to load the (application) class it
seems.

Thanks,
Best,
- Ajay





--
The mind is everything; what you think, you become. -- Buddha

On 7/20/07, Andrus Adamchik wrote:
This felt like a nested ClassLoader issue from the beginning... I am
not familiar with the Axis2 archive details, but is it possible to
put Cayenne jar at the same level as the application classes?

Alternatively you can try upgrading to 3.0M1 (you can grab an
*unofficial* build from here: http://people.apache.org/~aadamchik/
release/3.0M1/). 3.0 uses String class names as keys and should
hopefully be free from this problem. Please let me know if that
worked - we will definitely need to fix it if it is still broken in 3.0.
Good catch. This is also obsolete in 3.0 - we can use commons
logging. Let me clean it up.

Andrus

On 7/20/07, Ajay H. Daptardar wrote:
Hi Andrus,

I tried the 3.0M1 build and am still getting the class not found
error
although manifest as a CayenneRuntimeException caused by
ClassNotFoundException.

Here is a trace:

Caused by: org.apache.cayenne.CayenneRuntimeException: [v.3.0M1
Jul 16
2007 22:17:38] Failed to load class com.app.AnnotationType:
com.app.AnnotationType
at org.apache.cayenne.map.ObjEntity.getJavaClass
(ObjEntity.java:238)
at
org.apache.cayenne.reflect.PersistentDescriptorFactory.getDescriptor(
PersistentDescriptorFactory.java:50)
at
org.apache.cayenne.reflect.ClassDescriptorMap.createDescriptor
(ClassDescriptorMap.java:122)
at
org.apache.cayenne.reflect.LazyClassDescriptorDecorator.checkDescript
orInitialized(LazyClassDescriptorDecorator.java:49)
at
org.apache.cayenne.reflect.LazyClassDescriptorDecorator.createObject(
LazyClassDescriptorDecorator.java:63)
at org.apache.cayenne.access.DataContext.newObject
(DataContext.java:752)
... 26 more
Caused by: java.lang.ClassNotFoundException: com.app.AnnotationType
at org.apache.catalina.loader.WebappClassLoader.loadClass
(WebappClassLoader.java:1359)
at org.apache.catalina.loader.WebappClassLoader.loadClass
(WebappClassLoader.java:1205)
at java.lang.ClassLoader.loadClassInternal
(ClassLoader.java:319)
at java.lang.Class.forName0(Native Method)
at java.lang.Class.forName(Class.java:242)
at org.apache.cayenne.util.Util.getJavaClass(Util.java:566)
at org.apache.cayenne.map.ObjEntity.getJavaClass
(ObjEntity.java:235)
... 31 more

The problem is not that Cayenne cannot be found, it occurs when
Cayenne tries to load the mapped classes using the web app class
loader. What I don't get is that why the web app class loader cannot
load the classes.

I am guessing that Axis2 creates a class loader for each web service,
loads the application classes and the jars in the lib folder (thats
why it finds Cayenne jars). But when Cayenne retrieves a class loader
(WebappClassLoader), this class loader is probably the one for the
Axis2 web service, not the one that Axis2 is using to load web
services.

Probably there is a way to get the class loader for the particular
web
service within the Axis2 (webapp) servlet.

Best,
- Ajay


in 3.0.
garbage...
be nice
used on
used on
resolver,
the
use the
logged and
garbage...
be nice
used on
INF/lib",
I get
have no

--
The mind is everything; what you think, you become. -- Buddha

On 7/21/07, Andrus Adamchik wrote:
Glad you solved the problem, but now it presents a challenge to us -
how do we support Axis class loading mechanism out of the box without
breaking everything else (thread class loader so far worked in all
environments I've tried...) I guess we need to do more research and
testing. Can I ask you a favor - could you please open a bug report
in Jira with a link to this discussion, so that it won't get
forgotten:

http://issues.apache.org/cayenne/

Thanks
Andrus