We've been using WAS 6.1 so far to deploy our web apps. Now we need to migrate to an economics-savvy Tomcat + OpenEJB solution. The OpenEJB 3.1.2 container is plugged into Tomcat 6.18, no standalone OpenEJB server here.
So here I am, trying to deploy my EJB 2.1 objects into OpenEJB...
My problem is that the EJBs code requires external .jar libraries, and I don't know where to put them so that they are actually taken into account into the container's classpath. It works fine into catalina.home/lib, so it does into openejb.home/lib. But still I'd rather find out a way to package the EJBs so that they are easy deployed with their linked .jar dropped right into place to be used by the OpenEJB container.
It can include building up an .ear or a .jar with the right descriptor files... Any solution that works is good enough for me.
Can possibly anyone help?
Ear Approach
You can just drop it into the Tomcat webapps/ directory and it will be picked up.
Example ear (valid):
myapplication.ear
lib/
lib/libraryOne.jar
lib/libraryTwo.jar
redEjbs.jar
blueEjbs.jar
Common mistake (invalid):
myapplication.ear
libraryOne.jar (err. not a javaee module)
libraryTwo.jar (err. not a javaee module)
redEjbs.jar
blueEjbs.jar
Only Java EE modules are allowed at the root. These are EJB jars, .war files, Connector .rar files and Application Client jars. Prior to Java EE 5, libraries had to be explicitly listed in an application.xml file. Java EE 5 and forward they can be added to a lib/ directory and be understood to be just plain jars as opposed to a Java EE module.
Collapsed EAR approach
In OpenEJB/Tomcat you can put all your libraries into the war file and be free of the ear concept. This is now part of Java EE 6.
mywebapp.war
WEB-INF/lib/libraryOne.jar
WEB-INF/lib/libraryTwo.jar
WEB-INF/lib/redEjbs.jar
WEB-INF/lib/blueEjbs.jar
Common mistake, including specs:
mywebapp.war
WEB-INF/lib/javax.ejb.jar (err. clashes with the related system library)
WEB-INF/lib/libraryOne.jar
WEB-INF/lib/libraryTwo.jar
WEB-INF/lib/redEjbs.jar
WEB-INF/lib/blueEjbs.jar
Doesn't sound like that is the issue, but adding for completeness.
Common mistake, broken dependencies:
tomcat/lib/libraryTwo.jar
mywebapp.war
WEB-INF/lib/libraryOne.jar
WEB-INF/lib/redEjbs.jar
WEB-INF/lib/blueEjbs.jar
The above is not invalid from a spec perspective and is impossible for the server to detect, but still can lead to apps not loading correctly. If libraryTwo.jar needs classes in libraryOne.jar then this app will never work as the Tomcat "lib" classloader cannot see classes from the "webapp" classloader, so classes from libraryTwo.jar will never successfully load. Unfortunately, the vm will almost never say the actual class that was missing and instead will report the first class in the chain of events that lead to needing a class that was missing. This is almost always a bean or servlet class.
Thanks David.
I tried all of the above, but still no luck.
The Collapsed EAR approach wouldn't work for me I guess, as I far as I know Tomcat 6.0.18 doesn't comply to the J2EE 6 specs. Maybe I'm wrong , but I tried and it didn't work anyway. So back to the standard EAR approach.
My EAR is organized exactly as described in your very first example. One Ejb jar, two library jars in /lib, and that's it. Tomcat still can't instanciate my EJB because the EJB class relates to an unreachable class from Library Jar Two.
I simplified my application.xml file so that it only declares one single EJB:
<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE ...>
<application>
<display-name>ProxyaEAR</display-name>
<module id="EjbModule">
<ejb>ProxyaEJB.jar</ejb>
</module>
</application>
Any other thoughts??
Related
I have created and deployed one war for my application.
I wanted to use derby for integration testing so I created one module in Jboss.
At run time I am getting ClassCastException for same class, since the class is getting loaded twice: first from war, then from my module's jar.
To elaborate, my war, say application.war contains myderby.jar and under my module i have added myderby.jar .My class, say Custom.java, is present in myderby.jar.
If you want a jar to be accessible to multiple WARs, JARs, or an EAR and a WAR/JAR - or in fact any such combination, you can include it as a global module. Here's how it can be done.
This might also help.
As Suggested I followed the following link
https://access.redhat.com/documentation/en-US/JBoss_Enterprise_Application_Platform/6/html/Administration_and_Configuration_Guide/Add_a_module_to_all_deployments.html and it worked for me.
I have a problem when deploying two ear files in Jboss 7 and would be thankful for your help.
Following scenario:
EAR 1 contains EJBs which are looked up by EAR 2 (also) at server startup. Thus, EAR 1 has to be deployed before EAR 2 (via jboss-deployment-structure.xml dependency settings).
Right after being deployed, EAR 1 also needs access to classes contained in EAR 2 because of Hibernate and JNDI related class loading (among others).
But as EAR 2 isn't deployed at that time, there's a need for EAR 1 to contain a client-jar file of EAR 2.
Now, the problem is that in the course of EAR 1 and EAR 2 configuration (at server startup) ClassCastExceptions occur because...
(non-EJB) Java object obj1, whose class C was loaded by the classloader of EAR 1, is bound in JNDI
and after being looked up, supposed to be cast to object obj2 whose class C was loaded by the classloader of EAR 2
Now I wonder, if there's a possibility that these common classes of EAR 1 and EAR 2 are being loaded with the same classloader in JBoss 7. I already tried to put them in a server module, which didn't work out.
Thanks a lot for your help in advance!
PS: I'm aware of the poor design declared above. But due to restrictions, I have to follow up on it.
To avoid class cast exceptions, the common libraries need to be put in a classloader that is common to all applications in the two EARs, and no other copies of those libraries should exist in each application.
If it's an option to use only one EAR instead of two, put all the WARs inside a single EAR, remove the common classes from the WARs and put them on the EAR library folder.
This will associate the common classes to the EAR classloader, which is common to all the applications running inside a EAR, so that would solve the problem.
If you must use two EARS, then the common classes need to be put in a classloader at the level of the server shared by all applications.
JBoss 7 is an OSGI based container that allows to create an isolated module with a few jars and link it to an application. So if you try this:
create a module with the common library AND it's dependencies, see instructions here
link the module to all applications
remove the copies of those libraries from all applications and leave them only at the module
It will work fine, but don't forget to put the dependencies of the common library in the module as well otherwise it will not work, the dependencies need to be visible at the level of the module, and there can be no duplicate jars between module and applications (otherwise class cast exceptions might happen).
Another way far less recommendable but it would also work, is to put the common classes at the level of the common classloader, see this diagram. The common classloader folder is located at $CATALINA_HOME/lib (Jboss is based internally on Tomcat).
Specially if there are other applications running in that server don't try the second option. It could help to have a look at a tool I built for these type of issues, JHades.
I have coded a small Java EE project that consists only of EJBs, helper classes and their tests.
The project is a maven project and creates a jar.
Right now, all tests are happening with JUnit and JMockit.
Now I want to deploy my application to a local glassfish 4.
What do I have to do, to deploy the project? I know that normaly a root Project with a root-Pom is created, that holds a EAR Project with the ear-Pom and the EJB Project with the ejb-jar.
I checked out the jee-simple-archetype, which was - for my kind of project - much to sophisticated and not simple at all. Could somebody explain how I package and deploy my app correctly?
I know that normaly a root Project with a root-Pom is created, that holds a EAR Project with the ear-Pom and the EJB Project with the ejb-jar
This is not necessarily the "normal" way. You can deploy a .jar containing EJBs on its own. Typically you would do this if the EJB beans are either called remotely (via RMI/#Remote or via SOAP/#WebService) or if the application contains some job-like logic (#Singleton/#Startup, or maybe JSR 352 Batching).
Could somebody explain how I package and deploy my app correctly?
In your pom.xml you should use <packaging>ejb</packaging>, that's basically it (assuming you have an otherwise valid pom.xml). The resulting jar can be deployed on its own. For GlassFish you would use the asadmin deploy command for this.
I am developing a Java EE 6 bottom-up JAX-WS to expose an EJB3.1 stateless session bean. The web service in a WAR is failing to install on deployment because it references an external jar (or shared library) which one can assume is not loaded yet.
The common suggestion is to include the jars in the /lib folder, which does fix the issue, however the jars need to remain in this external shared library location and NOT in the ear file, because they amount to 30MB.
What are some techniques to get around this issue in a Websphere (WAS v.8) environment or any server environment.
Some suggestions I have found include:
1. define classpath in META-INF file.
2. define the resources in deployment.xml
3. alter class loading order
4. (from ibm) In the case where the jars are part of a Shared Library configured on WebSphere Application Server, then a User Library must be used to configure the project for development before generating the WebService.
However, I have been unsuccessful to find any help online in these areas. Is there another technique or does anyone know anything about accomplishing this? Thanks in advance.
EDIT: If I specify the libraries in the META-INF using class-path, they are loaded before extensions, shared libraries..etc, but they are still loaded after the WAR which is not good. Again, this isn't a runtime issue because the web services are created at deployment on the fly.
I submitted a ticket to IBM. The libraries referenced by the web service are needed during deployment and must be bundled into the Ear in some fashion. I threw them in the web-inf/lib folder. However, if the referenced libraries then depend on additional libraries, these can be placed in the Shared Libraries. Seems odd to me too, but let's all just admit "shared libraries" are a hack anyways.
If you still have issues, just make sure your class loading is set to parent_last.
I did ear deployment in weblogic 10.It conatins war, ejb jar, APP-INF, META-INF. Now When I am calling the service from war, I am getting classnot found exception.When I deploy the war file , without using ear file this service works absoulutely fine.
How to resolve this problem. How classloader will check for jars
It's impossible to solve your problem without more details but as you asked for documentation on how classloaders work in WebLogic, you will find information in Understanding WebLogic Server Application Classloading. Also have a look at Understanding J2EE Application Server Class Loading Architectures on TheServerSide.com (quite old but still perfectly valid).
In your particular case, I'd like to know if you are using Manifest Class-Path entries. More details on how your EAR is structure exactly would be also welcome. Please update your question accordingly.