7 Replies Latest reply on Aug 19, 2005 11:03 AM by brittm

    How do I get a list of nodes?

    guillem
    guillem Aug 17, 2005 1:10 PM

      I've got the following process definition:

      <process-definition name="traspaso_propiedad">
 <start-state name="start">
 <transition to="s" />
 </start-state>
 <state name="s">
 <transition to="end" />
 </state>
 <end-state name="end">
 </end-state>
</process-definition>


      I'm trying to get a list of nodes to print out each name, my code is: 
      Iterator istates = myProcessDefinition.getNodes().iterator();
 while (istates.hasNext()){
 Node tempNode = (Node)istates.next();
 System.out.println("NODE NAME: " + tempNode.getName());
 }


      But it prints nothing, i've checked and the list of nodes is empty, any idea about what am I missing?

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        • 1. Re: How do I get a list of nodes?
          peterj
          peterj Aug 17, 2005 1:44 PM (in response to guillem)

          My code to pring out the node names looks almost like yours. I would guess that the myProcessDefinition valirable doesn't contain your process. Try printing out myProcessDefinition.getName() as see if you get "traspaso_propiedad".

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          • 2. Re: How do I get a list of nodes?
            guillem
            guillem Aug 18, 2005 3:12 AM (in response to guillem)

            I tried to print out the process definition name and i get "traspaso_propiedad". I've also checked in the database the table jbpm_node and the nodes are there with the correct process definition. Can't figure out what's wrong maybe something about beginTranscation() and commitTransaction()?

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            • 3. Re: How do I get a list of nodes?
              aguizar
              aguizar Aug 18, 2005 12:22 PM (in response to guillem)

              Is the call to ProcessDefinition.getNodes() placed before you close your JbpmSession? Almost everything from the jBPM database is lazily loaded, and an empty collection is a typical symptom of a closed session.

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              • 4. Re: How do I get a list of nodes?
                peterj
                peterj Aug 18, 2005 12:36 PM (in response to guillem)

                I looked at my code and I have a beginTransaction before doing anything, and a commitTransaction after printing out all the names.

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                • 5. Re: How do I get a list of nodes?
                  guillem
                  guillem Aug 19, 2005 4:14 AM (in response to guillem)

                  Now it works, i've looked in the jbpm_processdefinition table and checked that, actually there were two rows with the same version of the same processdefinition but in jpmb_node table all my nodes belonged to the second one, removing the first row has corrected the problem, now I must check why the "empty" :P thanks to everyone for the help ;)

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                  • 6. Re: How do I get a list of nodes?
                    guillem
                    guillem Aug 19, 2005 5:13 AM (in response to guillem)

                    Finally I've found out why there were two records for each process definition version, it was because my code to add one new process definition looked like:

                    ProcessDefinition myProcessDefinition = ProcessDefinition.parseXmlResource(myProcessDefinitionFile);
jbpmSession.beginTransaction();
jbpmSession.getGraphSession().saveProcessDefinition(myProcessDefinition);
jbpmSession.commitTransaction();


                    But GraphSession.saveProcessDefinition() saves it with its own transaction.
                    By removing my beginTransaction()/commitTransaction() the problem has been solved.

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                    • 7. Re: How do I get a list of nodes?
                      brittm
                      brittm Aug 19, 2005 11:03 AM (in response to guillem)

                      I can't see how nested transacitons should duplicate the entry. That sounds more to me like a bug. I had come to the conclusion that

                      jbpmSession.getGraphSession().saveProcessDefinition(myProcessDefinition);

                      simply does not properly support versioning of the process definition. I use the following code instead and never have any problems: 
                      jbpmSession.beginTransaction();
 ProcessArchiveDeployer pad = new ProcessArchiveDeployer(jbpmSessionFactory);

 String resource = request.getParameter("file");
 if(resource.toUpperCase().endsWith(".XML")) {
 FileInputStream fis = new FileInputStream(resource);
 ProcessDefinition pd = ProcessDefinition.parseXmlInputStream(fis);
 //jbpmSession.getGraphSession().saveProcessDefinition(pd); //does not handle versioning
 pad.deployProcessDefinition(pd);
 }else if(resource.toUpperCase().endsWith(".PAR")) {
 pad.deployResource(resource);
 }

jbpmSession.commitTransaction();


                      -Britt

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