web app packaging and classloading

[jboss_dev_16]

Hi All,

I have a question regarding deployment of a web app within JBoss AS 5.

What I would like is to have is the web app we are developing to not have to include all the 3rd party libraries in the web-inf/lib and to move them outside of the .war.

I know that you can place jar files into the server/{profile}/lib directory and they will be available to the web app.

Personally I don't like this idea of putting the jars here as could then cause issues if other apps are deployed.

What I would like is to package all the libraries up together say in an ear or a seperate war and then reference them from the web app.

In Weblogic we can do this by creating a shared-lib as an ear and then reference that ear from your app.

Is there an equivilant concept in JBoss?

I guess the scenario would be akin to having multiple .war/.ear files that have the same library dependencies and not wanting to have to copy the libraries into each of the war/ear files.

Many Thanks in advance,

[alesj]

Is there an equivilant concept in JBoss?

Sure.

You could bundle all the libs into .ear/lib, and put this .ear into new CL domain via jboss-classloading.xml.

Then have your initial .war reference the same new CL domain; either as a parent or its domain.

* http://java.dzone.com/articles/jboss-microcontainer-classloading

[jboss_dev_16]

Thanks, I will try this out. In initial investigation down this route I had problems though that may have been due to misconfiguration of the jboss-classloading.xml file. Are there example .ear and .war classloading XML files for a starting point?

[alesj]

Are there example .ear and .war classloading XML files for a starting point?

jboss-classloading.xml is the same for all deployment types:

* http://community.jboss.org/wiki/JBoss5custommetadatafiles

More examples can be found in JBCL and Deployers tests:

* http://anonsvn.jboss.org/repos/jbossas/projects/jboss-cl/trunk/

* http://anonsvn.jboss.org/repos/jbossas/projects/jboss-deployers/trunk/

[jboss_dev_16]

That should help, thanks.

One last question, will the ear get loaded first then by default once the war is referecing it in its jboss-classloding.xml?

[alesj]

will the ear get loaded first then by default once the war is referecing it in its jboss-classloding.xml?

No, as we configured it now it's only referencing the same CL domain, not the actual deployment.

For that you would either have to use:

* <requirements><module ...> ... --- in jboss-classloading.xml

* jboss-dependency.xml from custommetadatafiles link

Meaning you somehow need to state an explict dependency between deployments.

[jboss_dev_16]

This sounds like why I was having issues with geting the war to see the jars in the ear.

Thanks for the help.

[jboss_dev_16]

OK, I have tried the jboss-classloading.xml and jboss-dependency.xml route and I am still hitting a brick wall....

As mentioned before I have a .war file and a .ear file.

I want all library code (Spring, commons-* libs, etc) and java services we are writing to be contained in the .ear and only the web app code, jsp's, javascript, etc

to be contained in the .war.

It appears that I can only get the web app to look inside the web-inf lib foder for classes and not to inspect the .ear for libraries, services etc.

I have the foolowing jboss-classloading.xml in the .war file

<classloading xmlns="urn:jboss:classloading:1.0" 

    name="my_webapp" 

    domain="my_web_domain"

    version="0.0.0"

    parent-domain="parent_domain" 

    export-all="NON_EMPTY" 

    import-all="true" parent-first="true"> 

</classloading> 

And the jboss-dependency.xml is

<dependency xmlns="urn:jboss:dependency:1.0">

    <item whenRequired="Real" dependentState="Create">my_ear_file</item>

</dependency>

For the .ear I have to following jboss-classloading.xml

<classloading xmlns="urn:jboss:classloading:1.0" 

    name="my_shared_lib"

    version="0.0.0"

    parent-domain="DefaultDomain"   

    domain="parent_domain"

    export-all="NON_EMPTY" 

    import-all="true"

    parent-first="false"

    top-level-classloader="true"> 

</classloading> 

I had thought that the web app would attempt to load the classes from the web-inf/lib or classes directory first and then delegate to the parent

if they cannot be found, the parent being the ear in this case.

What I see is the web app not being able to find classes in the ear and thus throwing ClassNotFoundException.

So, I was moving jar files back into the .war but so that the ClassNotFoundException for Class X was resolved, but then Class Y, in the .ear, which

also relied on Class X was failing to get loaded. I suspect this was due to Class Y which is in the parent CL domain not being able to see the child?

If I can get the .war to see the jars etc in the .ear I think my problem is solved... I hope...

Any thoughts??

Cheers,

[alesj]

In that jboss-dependency.xml, dependentState should be of DeploymentStage not ControllerState.

Since it's deployments that need to be "wired", not deployment and a service.

Try putting "ClassLoader":

* http://anonsvn.jboss.org/repos/jbossas/projects/jboss-deployers/trunk/deployers-client-spi/src/main/java/org/jboss/deployers/spi/deployer/DeploymentStages.java

And I guess you have aliases.txt in .ear/META-INF?

Other things look OK.

[jboss_dev_16]

Ales Justin wrote:

In that jboss-dependency.xml, dependentState should be of DeploymentStage not ControllerState.

Since it's deployments that need to be "wired", not deployment and a service.

Try putting "ClassLoader":

* http://anonsvn.jboss.org/repos/jbossas/projects/jboss-deployers/trunk/deployers-client-spi/src/main/java/org/jboss/deployers/spi/deployer/DeploymentStages.java

And I guess you have aliases.txt in .ear/META-INF?

Other things look OK.

yes, I have aliases.txt in the correct location.

I'll try the change you suggest for jboss-dependency.xml.

Thanks again.