[dajevtic]

Sorry, forgot to mention that portlets accessing this Manager must run in the same JVM (on the same server)

[julien1]

Thanks for sharing the idea. It is part of the thing we would like to add in future release.

[dajevtic]

A good idea would be to use the session Id of the user as the key. That way, another portlet could retrieve the object by just passing the session id to the Manager class and retrieve the contents.

We mainly use this to store request parameters which are posted from one portlet and being retrieved by another one.

This can be implemented as a stack as well, pushing parameters from one portlet and popping the parameters from another portlet.

I'll be glad to help if anyone has problems/questions regarding this matter.

Regards!

[julien1]

would you work on implementing in JBoss Portal under a "tools" module that would contain various tools for inter portlet communication ?

[dajevtic]

Certainly, I would be glad to contribute any helpful tools required for interportlet communication.

[dajevtic]

I have developed a PortletForm class, which is similar to the above example. It can be configure to accept any form data posts from a user for a specific portlet and make the form data available to another registered portlet (for the same user). This may be a nice solution for Jboss Portal to handle forms inside portlets and communicate them to other portlets. What do you think?

[julien1]

could you give example for instance of how it can be used ?

[dajevtic]

Of course. Here is a small code snippet of how it can be used:

Portlet with form:

public void processAction(ActionRequest request, ActionResponse response) {
PortletFormManager.getInstance().setFormData(request);
}

places all request parameter names and parameter values into the PortletFormManager.

Portlet displaying the values:
Hashtable requestParameters = PortletFormManager.getInstance().getObject(request.getPortletSession().getId());
if (requestParameters != null) {
Iterator parameterValues = requestParameters.values().iterator();
while (parameterValues.hasNext()) {
System.out.println((String)parameterValues.next());
}
}

This is the easiest way. The PortletFormManager also has methods for retrieving the form data as a Map, Collection or Enumeration.

[sdhaliwal]

Will this approach for Interportlet communication work for communication across portlets deployed as part of separate webapps. What will be the behavior in a clustered environment. We have a requirement where portlets deployed as part of different webapps (part of the same portal) must exchange some information and change behavior accordingly. The portal will be deployed in a jboss cluster.

[julien1]

clustered env would need something more complicated

[sdhaliwal]

If you are using per webapp class loader (not using JbossWebLoader) which will be the default for the final release, even the portlets in different webapps within the same JVM could have a problem. We have been toying with the idea of using TreeCacheAop

[julien1]

unless you put the jar in the lib or deploy directory of JBoss and not in the war files, in that case the scope would be per VM

using tree cache replicated would be a good idea too but needs more work to put in place.

[dajevtic]

In order to make it work for portlets within seperate webapps, the PortletFormManager.jar should be deployed to the
"jboss-portal.sar\lib" directory. Then distributed webapp's portlets can use it without any problem.

I have to check the behavior in a distributed environment, but I doubt that it will work, unless I use one of the two possibilities:

1.) Implement persistence for form data
or
2.) Make the PortletFormManager a web service which receives and sends data via http

But I will check so that I can give a 100% educated answer

[dajevtic]

Sorry, the above articles were posted while I was editing my post, so I didn't see that other answers were already provided.
I agree that tree cache replicated would be a good solution.

[dajevtic]

Hello there, I'm back with some news regarding Interportlet Communication. I've tested the PortletFormManager with the per webapp class loader and it produces the same results as the JbossWebLoader. So there shouldn't be any problems, because the class is explicitly declared to be singleton. As expected, a disitributed environment does not work.
I therefore tested the 3 possible solutions: persistence, web service and TreeCacheAOP. They all work fine in a distributed environemt, however I'm still dealing with some security issues. I will run some further tests about performance, as well. If anoyone is interested I'll post the results in this forum?! Regards, dj