[jboss-dev] Dependencies to JBoss as core libs

[Adrian]

On Wed, 2007-06-27 at 14:01 +0100, Tim Fox wrote:
> The JBoss Messaging Bridge MBean has dependencies on JMSProviderLoader 
> since it uses these to connect to its source and target destinations.
> 
> Are you suggesting we move the Bridge MBean into the AS project?

No, I'm suggesting you think about providing a clean api
which can be used by the AS to integrate with its configuration
mechanisms.

Trying to do integration in your project just leads
to JBAS-1796 style problems and bad api!

IOC 101

Why doesn't the bridge just take connection factories
and destinations as injections (javabean setters)?
That is a trivial "no dependency required"
configuration api.

public SimpleBridge
{
   setSourceConnectionFactory(XAConnectionFactory cf) {};
   setTargetConnectionFactory(XAConnectionFactory cf) {};
   setSourceDestination(Destination destination) {};
   setTargetDestination(Destination destination) {};

   ...
}

ANY FORM OF INTEGRATION IS NOW EASY

For standalone ease of use, you could subclass the simple bridge
with a version that does something like (psuedo code):

public JNDIBridge extends SimpleBridge
{

   public void setTargetDestinationJndiName(String targetJNDI) {}

   public void setJNDITargetProperties(Properties targetProperties) { }

   // Create lifecycle that does base setters from jndi configuration
   public void create() throws Exception
   {
      if (targetJNDI == null)
         throw new IllegalStateException("Target jndi name not set!");

      InitialContext context;
      if (targetProperties == null)
         context = new InitialContext();
      else
         context = new InitialContext(targetProperties);
      try
      {
          Destination d = (Destination) context.lookup(targetJNDI);
          setTargetDestination(d);

          etc....
      }
      finally
      {
         context.close();
      }

   }
}

Which is basically what the JMSProvider really does anyway!

JBOSS INTEGRATION IS ALSO TRIVIAL

In the appserver we could have a JNDIProvider based version
to integrate with the current way of configuring jms servers
in one place.

public JNDIProviderBridge extends SimpleBridge
{
   public void setSourceJNDIProviderName(String jndiName) {}
   public void setTargetJNDIProviderName(String jndiName) {}
   public void setSourceDestination(String jndiName) {}
   public void setTargetDestination(String jndiName) {}

   etc....
}

-- 
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Adrian Brock
Chief Scientist
JBoss, a division of Red Hat
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