[jboss-user] [jBPM] - Re: In memory TaskClient without Mina or JMS

Mon Jun 20 02:43:08 EDT 2011

Daniele Ulrich [http://community.jboss.org/people/daniele.ulrich] created the discussion

"Re: In memory TaskClient without Mina or JMS"

To view the discussion, visit: http://community.jboss.org/message/610954#610954

--------------------------------------------------------------
I did it this way (although it is possible to work directly with the locally instantiated TaskService, see at the end):

This has, however, some drawbacks: all events from the task service can only be recevied by a client that registers locally (in jvm) to the task service. And I'm working on a good solution for a proper JTA integration (injected EntityManager)  to support an integration within an appserver. 

/*
$Id: LocalHumanTaskHandler.java 234 2011-06-20 06:24:39Z Daniele $
*/
**package
**ch.niceneasy.process.handler;

**import
**org.jbpm.process.workitem.wsht.WSHumanTaskHandler;
**import
**org.jbpm.task.service.TaskClient;
**import
**org.jbpm.task.service.TaskService;

/**
* The class LocalHumanTaskHandler allows to use Human Tasks on a local
* connection to the task service.
*/
**public
****class** LocalHumanTaskHandler **extends**WSHumanTaskHandler {

/**

* Instantiates a new local human task handler.
* 
* 
**@param**taskService

* the task service (locally instantiated, singleton)
*/

**public**LocalHumanTaskHandler(TaskService taskService) {
InJVMConnector inJVMConnector = 
**new**InJVMConnector(taskService);
TaskClient taskClient = 
**new**TaskClient(inJVMConnector);
inJVMConnector.setTaskClient(taskClient);
setClient(taskClient);
}
}

/*
$Id: InJVMConnector.java 234 2011-06-20 06:24:39Z Daniele $
*/
**package
**ch.niceneasy.process.handler;

**import
**java.io.IOException;
**import
**java.util.HashMap;
**import
**java.util.Map;
**import
**java.util.concurrent.atomic.AtomicInteger;

**import
**org.drools.SystemEventListenerFactory;
**import
**org.drools.task.service.ResponseHandler;
**import
**org.jbpm.task.service.BaseHandler;
**import
**org.jbpm.task.service.SessionWriter;
**import
**org.jbpm.task.service.TaskClient;
**import
**org.jbpm.task.service.TaskClientConnector;
**import
**org.jbpm.task.service.TaskClientHandler;
**import
**org.jbpm.task.service.TaskServerHandler;
**import
**org.jbpm.task.service.TaskService;

/**
* The class InJVMConnector is a replacement for the mina orhornetq
* TaskClientConnectors. It allows an in
-JVM connection by implementing the

* TaskClientConnector interface. Although it is also possible to use
* TaskService and TaskServiceSession directly, this approach staysstricly
* compatible to the jbpm
-human-task framework.

* 
* Tested on JBoss AS 6.1 with multiple datasources, I had to remove the persistence.xml and
* orm.xml from the jpb
-human-task.jar and replace it as follows:

* 
* 
<pre>

* ...
* &lt;persistence
-unit name="org.jbpm.task" transaction-type="RESOURCE_LOCAL"&gt;

* &lt;non
-jta-data-source&gt;java:/org.jbpm.task&lt;/non-jta-data-source&gt;

* &lt;mapping
-file&gt;META-INF/orm-jbpm.xml&lt;/mapping-file&gt;

* ...
* 
</pre>

* 
* As the persistence layer of jbpm
-human-task performs local transactions (explicit commits), 

* the datasource has to be defined as follows:
* 
* 
<pre>

* ...
* &lt;no
-tx-datasource&gt;

* &lt;jndi-name&gt;org.jbpm.task&lt;/jndi-name&gt;

* ...
*</pre>

* 
*/
**public
****class** InJVMConnector **implements**TaskClientConnector {

/** The task client. */

**private**TaskClient taskClient;

/** The task server handler. */

**private**TaskServerHandler taskServerHandler;

/** The counter. */

**private** AtomicInteger counter = **new**AtomicInteger();

/** The local handler. */

**private** LocalHandler localHandler = **new**LocalHandler();

/**

* Instantiates a new in jvm connector.
* 
* 
**@param**taskService

* the task service
*/

**public**InJVMConnector(TaskService taskService) {
taskServerHandler = 
**new**TaskServerHandler(taskService,
SystemEventListenerFactory.getSystemEventListener());
}

/*

* (non-Javadoc)
* 
* @see org.jbpm.task.service.TaskClientConnector#connect()
*/

@Override

**public** **boolean**connect() {

**return** **true**;
}

/*

* (non-Javadoc)
* 
* @see org.jbpm.task.service.TaskClientConnector#connect(java.lang.String,
* int)
*/

@Override

**public** **boolean** connect(String address, **int**port) {

**return**connect();
}

/*

* (non-Javadoc)
* 
* @see org.jbpm.task.service.TaskClientConnector#disconnect()
*/

@Override

**public** **void** disconnect() **throws**Exception {
}

/*

* (non-Javadoc)
* 
* @see org.jbpm.task.service.TaskClientConnector#write(java.lang.Object)
*/

@Override

**public** **void**write(Object message) {

**try**{
taskServerHandler
.messageReceived(
**new**LocalSessionWriter(), message);
} 
**catch**(Exception e) {

// **TODO**Auto-generated catch block

e.printStackTrace();
}

}

/*

* (non-Javadoc)
* 
* @see org.jbpm.task.service.TaskClientConnector#getHandler()
*/

@Override

**public**BaseHandler getHandler() {

**return**localHandler;
}

/*

* (non-Javadoc)
* 
* @see org.jbpm.task.service.TaskClientConnector#getName()
*/

@Override

**public**String getName() {

**return** "localConnection";
}

/*

* (non-Javadoc)
* 
* @see org.jbpm.task.service.TaskClientConnector#getCounter()
*/

@Override

**public**AtomicInteger getCounter() {

**return**counter;
}

/**

* Gets the task client.
* 
* 
**@return**the task client

*/

**public**TaskClient getTaskClient() {

**return**taskClient;
}

/**

* Sets the task client.
* 
* 
**@param**taskClient

* the new task client
*/

**public** **void**setTaskClient(TaskClient taskClient) {

**this**.taskClient = taskClient;
localHandler.setClient(taskClient);
}

/**

* The Class LocalSessionWriter.
*/

**public** **class** LocalSessionWriter **implements**SessionWriter {

/*

* (non-Javadoc)
* 
* @see org.jbpm.task.service.SessionWriter#write(java.lang.Object)
*/

@Override

**public** **void** write(Object message) **throws**IOException {

**try**{
localHandler.messageReceived(
**null**, message);
} 
**catch**(Exception e) {

**throw** **new**IOException(e);
}
}
}

/**

* The Class LocalHandler.
*/

**public** **class** LocalHandler **implements**BaseHandler {

/** The handler. */

**private**TaskClientHandler handler;

/** The response handlers. */

**protected** Map<Integer, ResponseHandler> responseHandlers = **new**HashMap<Integer, ResponseHandler>();

/**

* Instantiates a new local handler.
*/

**public**LocalHandler() {
handler = 
**new**TaskClientHandler(responseHandlers,
SystemEventListenerFactory.getSystemEventListener());
}

/*

* (non-Javadoc)
* 
* @see org.jbpm.task.service.BaseHandler#addResponseHandler(int,
* org.drools.task.service.ResponseHandler)
*/

**public** **void** addResponseHandler(**int**id, ResponseHandler responseHandler) {
responseHandlers.put(id, responseHandler);
}

/**

* Gets the client.
* 
* 
**@return**the client

*/

**public**TaskClient getClient() {

**return**handler.getClient();
}

/**

* Sets the client.
* 
* 
**@param**client

* the new client
*/

**public** **void**setClient(TaskClient client) {
handler.setClient(client);
}

/**

* Exception caught.
* 
* 
**@param**writer

* the writer
* 
**@param**cause

* the cause
* 
**@throws**Exception

* the exception
*/

**public** **void**exceptionCaught(SessionWriter writer, Throwable cause)

**throws**Exception {
handler.exceptionCaught(writer, cause);
}

/**

* Message received.
* 
* 
**@param**writer

* the writer
* 
**@param**message

* the message
* 
**@throws**Exception

* the exception
*/

**public** **void**messageReceived(SessionWriter writer, Object message)

**throws**Exception {
handler.messageReceived(writer, message);
}

}

}

Get user task locally:

/* @Singleton @Startup KnowledgeBaseBean { @Postconstruct ....*/

KnowledgeBaseBean 
knowledgeBaseBean ;   

##

**public** List<TaskSummary> getOpenTasks() {TaskServiceSession session = 

**null**;

**try** {session = 

knowledgeBaseBean.getTaskServiceSession();

**return** session.getTasksAssignedAsPotentialOwner("mary", "en-UK");} 

**finally** {

**if** (session != **null**) {session.dispose();
}
}

}

Cheers, Daniele 

 @Inject
--------------------------------------------------------------

Reply to this message by going to Community
[http://community.jboss.org/message/610954#610954]

Start a new discussion in jBPM at Community
[http://community.jboss.org/choose-container!input.jspa?contentType=1&containerType=14&container=2034]

-------------- next part --------------
An HTML attachment was scrubbed...
URL: http://lists.jboss.org/pipermail/jboss-user/attachments/20110620/0a8801b8/attachment-0001.html 