Tips for Developing JMS Client for WebSphere Application Server

Following are some tips for developing a JMS client for WAS.

* First, we need to put the right jar files on the client’s classpath. Following jars are required: com.ibm.ws.sib.client.thin.jms_<WAS version>.jar, com.ibm.ws.ejb.thinclient_<WAS version>.jar. If you’re using Oracle/Sun JDK, you’ll also need com.ibm.ws.orb_<WAS version>.jar as IBM libraries rely on IBM ORB implementation. IBM JDK has it built-in but Oracle’s obviously does not. These jars are available from the “runtimes” directory of your WAS installation. It is a good idea to make sure that the version of your client jars matches the version of your target WAS installation, including the fixpack level. You may want to update your client jars every time a new fixpack is installed.

* If you’re not using DNS, you’ll need to add the host name of the WAS server to the host file on your client machine, otherwise you’re bound to get a cryptic ORB error message. You can find WAS host name by going to Server/Server types/ WebSphere Application Servers in admin console.
By the way, most ORB error messages are cryptic; it is very rare to see the root cause of the problem in the message. The way to deal with it is to enable ORB tracing. Add -Dcom.ibm.CORBA.Debug=true to your JDK parameters; other debug/tracing parameters are explained here.

* Another frequent source of errors is a missing bootstrap property in the connection factory configuration. It is specified in the “provider endpoint” field and has a form of <host>:<SIB_Port>:BootstrapBasicMessaging. If this is not provided, WAS will attempt to bootstrap the messaging engine using localhost.

* Most JMS examples use JNDI lookup in order to get a queue object. It is more efficient to use session.crerateQueue() method. Note that in this case you need to provide the name of the JMS destination as opposed to the queue JNDI name. This is the “Queue name” parameter on the queue configuration screen in WAS admin console.

* Finally, not all developers are aware that WAS admin console has a built-in JMS queue/topic browser. It takes a few steps to get to it from the console: Buses/Your bus name/Destinations/Your destination/Queue points/Your queue point/Runtime/Messages.

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