Issue using XStreamToObject

[tobysaville]

Hello,

I am trying to convert xml to an object using the XStreamToObject action. I use the SystemPrintln action to print the xml that is being passed in (which is generated from XStream originally):

12:27:29,337 INFO [STDOUT] [<com.easynet.ripe.model.AllocationRequest>
 <addressLine1>line1</addressLine1>
 <multiline>0</multiline>
 <ipSize>0</ipSize>
 <nat>false</nat>
 <smpf>false</smpf>
 <ripeUsername>toby.saville</ripeUsername>
 <ripePassword>letmein</ripePassword>
</com.easynet.ripe.model.AllocationRequest>].

And the stack trace that gets generated by the XStreamToObject action when it tries to convert it into an object:

12:27:42,524 WARN [ActionProcessingPipeline] Unexpected exception caught while processing the action pipeline
com.thoughtworks.xstream.converters.ConversionException: addressLine1 : No ClassLoaders found for: addressLine1
---- Debugging information ----
required-type : com.easynet.ripe.model.AllocationRequest
cause-message : addressLine1 : No ClassLoaders found for: addressLine1
class : com.easynet.ripe.model.AllocationRequest
message : addressLine1 : No ClassLoaders found for: addressLine1
path : /com.easynet.ripe.model.AllocationRequest/addressLine1
cause-exception : com.thoughtworks.xstream.alias.CannotResolveClassException
-------------------------------
 at com.thoughtworks.xstream.core.TreeUnmarshaller.convertAnother(TreeUnmarshaller.java:45)
 at com.thoughtworks.xstream.core.ReferenceByXPathUnmarshaller.convertAnother(ReferenceByXPathUnmarshaller.java:39)
 at com.thoughtworks.xstream.core.TreeUnmarshaller.start(TreeUnmarshaller.java:99)
 at com.thoughtworks.xstream.core.ReferenceByXPathMarshallingStrategy.unmarshal(ReferenceByXPathMarshallingStrategy.java:12)
 at com.thoughtworks.xstream.XStream.unmarshal(XStream.java:552)
 at com.thoughtworks.xstream.XStream.unmarshal(XStream.java:540)
 at org.jboss.soa.esb.actions.converters.XStreamToObject.fromXmlToObject(XStreamToObject.java:187)
 at org.jboss.soa.esb.actions.converters.XStreamToObject.process(XStreamToObject.java:106)
 at org.jboss.soa.esb.listeners.message.ActionProcessingPipeline.process(ActionProcessingPipeline.java:265)
 at org.jboss.soa.esb.listeners.message.MessageAwareListener$1.run(MessageAwareListener.java:297)
 at java.util.concurrent.ThreadPoolExecutor$Worker.runTask(ThreadPoolExecutor.java:650)
 at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:675)
 at java.lang.Thread.run(Thread.java:595)
Caused by: com.thoughtworks.xstream.alias.CannotResolveClassException: addressLine1 : No ClassLoaders found for: addressLine1
 at com.thoughtworks.xstream.mapper.DefaultMapper.realClass(DefaultMapper.java:35)
 at com.thoughtworks.xstream.mapper.MapperWrapper.realClass(MapperWrapper.java:18)
 at com.thoughtworks.xstream.mapper.XmlFriendlyMapper.realClass(XmlFriendlyMapper.java:44)
 at com.thoughtworks.xstream.mapper.MapperWrapper.realClass(MapperWrapper.java:18)
 at com.thoughtworks.xstream.mapper.ClassAliasingMapper.realClass(ClassAliasingMapper.java:49)
 at com.thoughtworks.xstream.mapper.MapperWrapper.realClass(MapperWrapper.java:18)
 at com.thoughtworks.xstream.mapper.MapperWrapper.realClass(MapperWrapper.java:18)
 at com.thoughtworks.xstream.mapper.MapperWrapper.realClass(MapperWrapper.java:18)
 at com.thoughtworks.xstream.mapper.DynamicProxyMapper.realClass(DynamicProxyMapper.java:46)
 at com.thoughtworks.xstream.mapper.MapperWrapper.realClass(MapperWrapper.java:18)
 at com.thoughtworks.xstream.mapper.MapperWrapper.realClass(MapperWrapper.java:18)
 at com.thoughtworks.xstream.mapper.MapperWrapper.realClass(MapperWrapper.java:18)
 at com.thoughtworks.xstream.mapper.ArrayMapper.realClass(ArrayMapper.java:70)
 at com.thoughtworks.xstream.mapper.MapperWrapper.realClass(MapperWrapper.java:18)
 at com.thoughtworks.xstream.mapper.MapperWrapper.realClass(MapperWrapper.java:18)
 at com.thoughtworks.xstream.mapper.MapperWrapper.realClass(MapperWrapper.java:18)
 at com.thoughtworks.xstream.mapper.CachingMapper.realClass(CachingMapper.java:27)
 at com.thoughtworks.xstream.converters.reflection.ReflectionConverter.determineType(ReflectionConverter.java:179)
 at com.thoughtworks.xstream.converters.reflection.ReflectionConverter.unmarshal(ReflectionConverter.java:102)
 at com.thoughtworks.xstream.core.TreeUnmarshaller.convertAnother(TreeUnmarshaller.java:38)
 ... 12 more

Could it be that the new line is confusing things somewhere?

I constructed a unit test to use this action outside of the ESB and it all works fine.

Any suggestions on why this might be?

cheers,
Toby

[beve]

Hi Toby,

could you post your action configuration from jboss-esb.xml?

Here's an example from one of our actions:

<action name="getVehicles" class="org.jboss.soa.esb.actions.converters.XStreamToObject">
 <property name="class-alias" value="rollingstock"/>
 <property name="incoming-type" value="se.xxx.Rollingstock"/>
 <property name="exclude-package" value="true"/>
 <property name="aliases">
 <alias name="vehicles" class="java.util.ArrayList"/>
 <alias name="vehicle" class="se.xxx.Vehicle"/>
 <alias name="serviceType" class="se.xxx.ServiceType"/>
 <alias name="phonenumbers" class="java.util.ArrayList"/>
 <alias name="phonenumber" class="se.xxx.PhoneNumber"/>
 <alias name="comments" class="java.util.ArrayList"/>
 <alias name="comment" class="se.xxx.Comment"/>
 </property>
</action>

What I'm thinking is that you might need to specify aliases for you classes, if you havn't done so already that is.

Regards,

Daniel

[tobysaville]

Hi Dave,

thanks for your help!

yeah, no aliases defined:

<action name="transform-from-stream"
 class="org.jboss.soa.esb.actions.converters.XStreamToObject">
 <property name="incoming-type"
 value="com.easynet.ripe.model.AllocationRequest" />
</action>

Can you provide hints on how aliases would work on this occasion? My understanding is that it is used to rename tags instead of using the class/attribute name, but i dont understand how this will help me in this case.

The part that really confuses me is that this action works in the unit test, outside of the ESB.

cheers,
toby

[beve]

Hi Toby,

Could you tell me, what is the type of "addressLine1" ? I looks as though XStream does not know about that type.
Could you try to add an alias for it and see if that helps?
Something like this:

<property name="aliases">
 <alias name="addressLine1" class="addressLine1s_Type"/>
</property>

/Daniel

[tobysaville]

Hi Daniel,

sorry for calling you Dave before, i was talking to my workmate Dave and got confused...

i should have elaborated - that field is simply a String. If i remove that field from the XML, the same problem arises but for the multiline field, which is an int. it seems that it is whatever tag is on the next line of the XML causes the problem.

thanks again,
tobes

[tfennelly]

Toby, would you be able to post details on the object graph you're trying to bind this xml data to.

Another option for you is to use the SmooksTransformer to populate the object graph from the XML. There are a number of quickstarts (e.g. transform_xml2pojo) on this, as well as some examples on the Smooks website.

[tfennelly]

"tobysaville" wrote:
Hi Daniel, sorry for calling you Dave before

His real name is Rodney ;-)

[beve]

sorry for calling you Dave before, i was talking to my workmate Dave and got confused...

No worries :)

Haven't seen this before. We had some trouble with Arraylist and things but not with String objects and primitives and this was the reason for adding the aliases.

/Daniel

[beve]

Hmm, can't understand why XStream cannot determine that addressLine1 is of type String. Is there anything fishy with the AllocationRequest class's getters?
Just a thought...

/Daniel

[tobysaville]

Hi Tom, Rodney :)

The object graph is as follows:

class RipeRequest {
 private String username, password

 // ... public getters & setters
}

class AllocationRequest extends RipeRequest {
 private String addressLine1, addressLine2 // etc
 private int multiline, ipSize //etc

 // ... public getters & setters
}

They are just standard POJOs with nothing special happening in the accessor methods. do you need any other info?

Thanks for the smooks suggestion, ill investigate that if i cant get anywhere with XStream.

Thanks again,
toby

[tobysaville]

i dont know if its important, but i forgot to mention that the RipeRequest class is abstract and implements Serializable:

public abstract class RipreRequest implements Serializable {
...
}

[beve]

Hey Toby,

I've tried with abstract classes and that works fine.

Could you try something for me?

Could your change your xml to this:

<AllocationRequest>
 <addressLine1>line1</addressLine1>
 <multiline>0</multiline>
 <ipSize>0</ipSize>
 <nat>false</nat>
 <smpf>false</smpf>
 <ripeUsername>toby.saville</ripeUsername>
 <ripePassword>letmein</ripePassword>
</AllocationRequest>

And then add the following property to the action :

<property name="class-alias" value="AllocationRequest"/>

Do you get the same error?

Thanks,

Daniel

[tobysaville]

Hi Daniel,

i tried your suggestions, and got an interesting result.

when using an alias, i can call the service once and it will work. if i call it again, i get the following error:

17:03:39,283 WARN [ActionProcessingPipeline] Unexpected exception caught while processing the action pipeline
com.thoughtworks.xstream.alias.CannotResolveClassException: AllocationRequest : No ClassLoaders found for: AllocationRequest
 at com.thoughtworks.xstream.mapper.DefaultMapper.realClass(DefaultMapper.java:35)
 at com.thoughtworks.xstream.mapper.MapperWrapper.realClass(MapperWrapper.java:18)
 at com.thoughtworks.xstream.mapper.XmlFriendlyMapper.realClass(XmlFriendlyMapper.java:44)
 at com.thoughtworks.xstream.mapper.MapperWrapper.realClass(MapperWrapper.java:18)
 at com.thoughtworks.xstream.mapper.ClassAliasingMapper.realClass(ClassAliasingMapper.java:49)
 at com.thoughtworks.xstream.mapper.MapperWrapper.realClass(MapperWrapper.java:18)
 at com.thoughtworks.xstream.mapper.MapperWrapper.realClass(MapperWrapper.java:18)
 at com.thoughtworks.xstream.mapper.MapperWrapper.realClass(MapperWrapper.java:18)
 at com.thoughtworks.xstream.mapper.DynamicProxyMapper.realClass(DynamicProxyMapper.java:46)
 at com.thoughtworks.xstream.mapper.MapperWrapper.realClass(MapperWrapper.java:18)
 at com.thoughtworks.xstream.mapper.MapperWrapper.realClass(MapperWrapper.java:18)
 at com.thoughtworks.xstream.mapper.MapperWrapper.realClass(MapperWrapper.java:18)
 at com.thoughtworks.xstream.mapper.ArrayMapper.realClass(ArrayMapper.java:70)
 at com.thoughtworks.xstream.mapper.MapperWrapper.realClass(MapperWrapper.java:18)
 at com.thoughtworks.xstream.mapper.MapperWrapper.realClass(MapperWrapper.java:18)
 at com.thoughtworks.xstream.mapper.MapperWrapper.realClass(MapperWrapper.java:18)
 at com.thoughtworks.xstream.mapper.CachingMapper.realClass(CachingMapper.java:27)
 at com.thoughtworks.xstream.core.TreeUnmarshaller.start(TreeUnmarshaller.java:95)
 at com.thoughtworks.xstream.core.ReferenceByXPathMarshallingStrategy.unmarshal(ReferenceByXPathMarshallingStrategy.java:12)
 at com.thoughtworks.xstream.XStream.unmarshal(XStream.java:552)
 at com.thoughtworks.xstream.XStream.unmarshal(XStream.java:540)
 at org.jboss.soa.esb.actions.converters.XStreamToObject.fromXmlToObject(XStreamToObject.java:187)
 at org.jboss.soa.esb.actions.converters.XStreamToObject.process(XStreamToObject.java:106)
 at org.jboss.soa.esb.listeners.message.ActionProcessingPipeline.process(ActionProcessingPipeline.java:265)
 at org.jboss.soa.esb.listeners.message.MessageAwareListener$1.run(MessageAwareListener.java:297)
 at java.util.concurrent.ThreadPoolExecutor$Worker.runTask(ThreadPoolExecutor.java:650)
 at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:675)
 at java.lang.Thread.run(Thread.java:595)

I can repeat this process over and over with the same result. seems like some type of caching issue perhaps?

thanks for your help!
- toby

[beve]

Hey Toby,

interesting...I'll try to reproduce this and see if we can figure out what's going on. Won't be until later today or tomorrow though.

Let me know if you find anything.

Thanks,

Daniel