topic Re: Engine Configuration in Alfresco Archive

Engine Configuration

jom_santos — Tue, 16 Oct 2012 15:39:04 GMT

I've a app develop using Liferay in a Tomcat server. I configured Activiti engine using *.cfg.xml file, with the engine jar in the specific portlet lib folder. But now I need to run the engine in the Tomcat lib/ext folder and I can't get access to the *.cfg.xml and if I try to create a Standalone Pr

Re: Engine Configuration

frederikherema1 — Tue, 16 Oct 2012 15:42:21 GMT

Where are you creating your process-engine? Make sure the class loader that loads that specific part of code, has access to the activiti.cg.xml location on the class path.

Re: Engine Configuration

jom_santos — Tue, 16 Oct 2012 15:56:56 GMT

I create my ProcessEngine in a ServletContextListener and the activiti engine jar is in the Tomcat lib/ext folder. Where should I place the *cfg.xml file?

Re: Engine Configuration

frederikherema1 — Tue, 16 Oct 2012 15:58:49 GMT

Perhaps WEB-INF/classes, this is always on you're class path. Usually, the config is app-specific and is a logical place to be…

Re: Engine Configuration

jom_santos — Tue, 16 Oct 2012 16:06:30 GMT

Putting the file doesn't make difference, I still can't init the engine.

On other side, when I try to init the engine without the *cfg.xml file, my code stops here:
ProcessEngine processEngine = ProcessEngineConfiguration.createStandaloneProcessEngineConfiguration();

Is there something I need to do?

Re: Engine Configuration

iam — Tue, 16 Oct 2012 20:08:01 GMT

@jom: Why you don't use activiti-web plugin for Liferay?
http://www.emforge.net/web/activiti-liferay

Re: Engine Configuration

frederikherema1 — Wed, 17 Oct 2012 07:44:23 GMT

The createStandaloneProcess…. still requires you to set the JDBC-properties and call .buildProcessEngine() afterwards to actually build it. Alternatively, use createStandaloneInMemProcessEngineConfiguration() to have it initialize an in-memory H2.

Re: Engine Configuration

jom_santos — Wed, 17 Oct 2012 08:52:09 GMT

Putting the file doesn't make difference, I still can't init the engine.

On other side, when I try to init the engine without the *cfg.xml file, my code stops here:
ProcessEngine processEngine = ProcessEngineConfiguration.createStandaloneProcessEngineConfiguration();

Is there something I need to do?

Obviously i meant :
ProcessEngineConfiguration engineConf = ProcessEngineConfiguration.createStandaloneProcessEngineConfiguration();
My code doesn't work past that, which mean that I can't even create the ProcessEngineConfiguration object (after create the "engineConf" object I try to configure the JDBC properties,, call buildProcessEngine() and then register that engine). Using createStandaloneInMemProcessEngineConfiguration() does not solve my problem cause we need to use MySQL databases. Is there anymore advises you can give me?

Re: Engine Configuration

frederikherema1 — Wed, 17 Oct 2012 08:54:19 GMT

Can you be a bit more specific than "My code doesn't work past that"? Is the thread blocked? What exception do you see?

Re: Engine Configuration

jom_santos — Wed, 17 Oct 2012 09:11:04 GMT

I can't catch any exception. Since I run that code in a ServletContextListener, declared in the web.xml file, I got this error SEVERE: Error listenerStart.

Re: Engine Configuration

frederikherema1 — Wed, 17 Oct 2012 11:03:30 GMT

Nothing more specific? really hard to figure out what the problem is and where to start looking, off course…

Re: Engine Configuration

jom_santos — Thu, 18 Oct 2012 09:00:25 GMT

Maybe you can help me if you have a general look of the system I'm talking about.

I have a Liferay Portal application running on a Tomcat server.
Adding to it, I have several portlets running in Liferay Portal, which use a set of shared Liferay services.
Those services are reachable through a jar file.

I also have a servlet running in that Tomcat using the Liferay services, which cause access conflits if the services.jar file is in the portlet lib folder (in which it was originally).
In order to solve those conflits I put the jar file in the Tomcat lib/ext folder.

Then I tried to integrate the Activiti engine with the Liferay Portal application, building my own interface to manage processes.
I put the activiti-engine-5.10.jar in the portlet WEB-INF/lib folder and the activiti.cfg.xml file in the WEB-INF/src folder and all was working fine until I needed to develop new Liferay services using Activiti classes.
Then I realized that the activiti-engine-5.10.jar file needed to be in the Tomcat lib/ext folder, because of the dependencies with the Liferay services jar.

With the activiti-engine-5.10.jar in Tomcat lib/ext folder I tried several ways to initialize the engine:
(1) - using activiti.cfg.xml in the portlet WEB-INF/src folder - obs: I don't know, since I moved the activiti-engine-5.10.jar if this file is in the right folder or if there's anything else I need to do;
(2) - using the Java API's ( createStandaloneProcessEngine().buildProcessEngine() ), specifying the JDBC properties and ignoring any configuration file; this code is present in a ServletContextListener, which is declared in the portlet web.xml file.´

Both ways didn't work for me:
(1) - The method ProcessEngines.init() does not throw an exception, but I get a NullPointerException as soon as call the method ProcessEngines.getDefaultProcessEngine(), which mean that either that the application can't find the activiti.cfg.xml file (perhaps it needed to be elsewhere) or that there's another error preventing the engine to run as it should;
(2) - I don't get any kind of exception, on the log of Tomcat I get the message SEVERE: Error listenerStart, and with some debug I found that the code after the creation of the ProcessEngineConfiguration isn't executed.

If you have any doubt let me know.

Off-topic: from what I saw in your source code I suppose that the method createStandaloneProcessEngine() should throw an ActivitiException. I've noticed this does not happen in the BPMN XML parser. Is it possible that we are unable to catch any ActivitiException at all?

Re: Engine Configuration

frederikherema1 — Fri, 19 Oct 2012 12:21:25 GMT

1) The activiti.cfg.xml file should be on your class path… WEB-INF/classes is one of the locations that is part of the class path. WEB-INF/src IS NOT.
2) There must be an exception thrown in the ProcessEngineConfiguration.buildProcessEngine(). have you found out what exception yet?

Re: Engine Configuration

jom_santos — Fri, 19 Oct 2012 15:05:26 GMT

(1) - tried, no different result.
(2) - there's no exception, I only got printed in the log of the server SEVERE: Error listenerStart. so far I was not able to catch any ActivitiException, like I say about the XML parser.

Re: Engine Configuration

jbarrez — Mon, 22 Oct 2012 08:57:36 GMT

Did you also try WEB-INF/lib. I've found that /classes doesn't always work on some tomcats.