I write a remote EJB interface (3.0) and write the EJB implementation. Now I deploy the EJB as an ear on WAS. On a separate machine I write a Java client to call the EJB. In the classpath of the client, I just need to have the EJB stub?
Is there anything else required on client side? I understand as a redundancy mechanism I am supposed to put the ejb and the bean also on client but i am not considering that here.
To call EJB from remote client you will need client libraries from application server that hosts your EJB, and EJB remote interface.
WepSphere client library name depends on server version which you are using, for v8 it will be com.ibm.ws.ejb.thinclient_8.0.0.jar located in app_server_root\runtimes directory
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We have a requirement for one standalone Java application that can push JMS message to a JMS queue configured on Weblogic, Websphere and JBoss application server.
Is there any generic JMS client library available, that we can use in our application for pushing the messages to any or all of these servers?
As we understand, there is a specific JMS client for each server (for e.g. wljmsclient.jar required for Weblogic target server, as we would need weblogic.jndi.WLInitialContextFactory to be available as Initial Context factory class, similarly for Websphere and JBoss). And we would like to avoid having 3 different JMS client libraries (1 each for server) in the same application.
However, the catch here is, destination server is not known during compilation time. Only during runtime, it will be known whether the given message is to be pushed to Weblogic, Websphere or JBoss server or all of them. Hence, there is a need for a deployed application to support all 3 servers during runtime.
Is there any alternative generic JMS client library?
You can develop your own client that supports the 3 servers.
Basically you need to have for your standalone application :
The different JMS provider jar on the classpath
For example a jms_config.properties file which stores the configuration for each server (initial context factory, etc.)
Then from a generic code you can build the InitialContext, JMS Queues, etc. depending on the target server.
Need to call a EJB service from the servlet context listener's contextInitialized() method. Application is running on JBOSS, though the context listener works fine, I'm not able to access the EJB bean through JNDI look up.
Because the web deployment in JBOSS happens before EJB beans are bound with JNDI tree. How to overcome from this? Is there a way to configure JNDI bind early or start the web deployment later once EJB's are completely deployed?
I had put Thread.sleep() before the service call in the contextInitialized() method, it is working fine in my JBoss5.1.0 GA, and the same did not work in other machines JBoss of same version.
Applications needs this because, we want to load some master data from the DB and make it available in the web layer (kind of caching). Does JBOSS startupmbean suit this requirement? If yes how can I make the data available to web layer?
Also if any alternative ways are available, please suggest.
Poll for the EJBs in contextInitialized(). So instead of just sleeping for a certain time, try to connect to the EJB. If that fails, sleep, and retry, until the EJBs are available. In this case the context initialization is blocked.
Implement the cache as a lazy one: Fill the cache during the first query (and use the same polling procedure: connect to the EJB, retry until it becomes available). In this case the cache blocks.
You could split your deployment into two parts: One for the EJBs, one for the web application. Then deploy the first, and delay deployment of the web application until the EJBs are bound (either by watching the log file or by trying bind to the EJB from a command line app)
I am new to MDB, so my questions may sound simple.
I implemented an MDB( serving as a Consumer ) using JDeveloper 11.1.7 and built a JAR file using deployment functionality. Now I need to deploy it to WebLogic 10.3 app server. I have several questions:
1) Should I deploy it as a library or as an application?
2) After I successfully deploy and it's in the "RUNNING" mode I assume it should be listening to the particular Queue I specified as a Resource in my MDB implementation. Is that correct?
3) When implementing an MDB all the examples only specify the "destination" but not the "ConnectionFactory". How does it know where to connect to?
Should I deploy it as a library or as an application?
Deploy as an application since the MDB will likely contain business logic specific to the app.
After I successfully deploy and it's in the "RUNNING" mode I assume it
should be listening to the particular Queue I specified as a Resource
in my MDB implementation. Is that correct?
Yes, if your JMS provider is local, specify the name bound in the local JNDI tree for the destination using destination-jndi-name.
When implementing an MDB all the examples only specify the
"destination" but not the "ConnectionFactory". How does it know where
to connect to?
If the MDB is consuming messages from the local WebLogic JMS provider, the container manages configuration for the connections and sessions automatically, so don't set provider-url, initial-context-factory, or connection-factory-jndi-name, unless you have a custom factory to use.
Refer to WebLogic 10.3 documentation for details:
We have modularised our application in clustered architecture like multiple servlet context with different datasource using hibernate and packaging in muliple war files. For eg: moldule1->hibernate sessionfactrory ->datasource 1(module1.war), moldule2->hibernate sessionfactrory ->datasource 2(module2.war)....
Spring RMI is used to integrate module1 and module2 services.
Here my question is, how to propagate the transaction between these modules, so that when module 2 fails to insert then module1 should roll back?
You can't without using EJB, per the Spring documentation:
Spring's support for RMI, you can transparently expose your services through the RMI infrastructure. After having this set up, you basically have a configuration similar to remote EJBs, except for the fact that there is no standard support for security context propagation or remote transaction propagation.
...and:
Last but not least, EJB has an advantage over RMI in that it supports standard role-based authentication and authorization and remote transaction propagation.
My j2EE app is currently running on ServiceMix. Now i want to add JMS to my app. The application should able to send/receive the JMS message to/from the queue that stays on MQSeries.
mq.hostname=10.3.6.19
mq.channel=CHANNEL
mq.queueManager=QManager
mq.port=1422
What i would like to do is:
1. Create a jndi.xml file and do configuration for jms stuff.
2. my app will initialize the context, look up jndi name, and create a connection, queueManager, queue. .etc
3. Develop send and receive methods.
My question is:
Can you tell me how to do 1st and 2nd steps.
(the script inside ServiceMix's jndi is diffrent with tomcat's
jndi and others.
ServiceMix using Spring based JNDI provider.
http://servicemix.apache.org/jndi-configuration.html)
I just ran into something similar with Weblogic. The following link uses spring-dm to integrate with websphere. It also takes it to the next logical step and adds camel to the mix.
http://lowry-techie.blogspot.com/2010/11/camel-integration-with-websphere-mq.html
Without using Spring-dm, you may run into classloader issues when trying to load the InitialContextFactory from the websphere jar (this is an issue I had with the Weblogic jar)