4 Replies Latest reply on Aug 5, 2013 8:41 PM by Senthil Sathiya

    Error starting process instance - getting  HTTP 500: Unknown error

    Senthil Sathiya Newbie

      Hi ,

       

      I have created a  simple bpmn job using jbpm 5.4 libraries "start --->  task -> and end event". I have attached a custom work item handler to the task ( CustomHandler.java) . I have been able to successfully commit the bpm file into guvnor and compile the package. The Jar file is copied into \jboss-as-7.1.1.Final\standalone\deployments\jbpm-gwt-console-server.war\WEB-INF\lib\ folder.

       

      When I open the  jbpm console (http://localhost:8080/jbpm-console/ ) i can see the process listed , but when I try to click start the process it errors out with the following msg :

       

      server/rs/process/definition/com.sample.bpmn.sampleHTformvariables/new_instance

      2013-07-31 16:23:37,610 [ERROR] <ul><li>URL: 'http://localhost:8080/gwt-console-server/rs/process/definition/com.sample.bpmn.sampleHTformvariables/new_instance'

      <li>Action: 'org.jboss.bpm.console.client.process.StartNewInstanceAction'

      <li>Exception: 'class com.google.gwt.http.client.RequestException'</ul>

       

      HTTP 500: Unknown error

      com.google.gwt.http.client.RequestException:

      HTTP 500: Unknown error

       

       

      When I replace the Task with a User Task , the process starts without any issues.

       

      I would appreciate some assistance on this , have been dealing with this issue for the past few days !

       

      Thanks in advance

       

      Senthil

        • 1. Re: Error starting process instance - getting  HTTP 500: Unknown error
          Maciej Swiderski Master

          you need to configure work item handler in console as it cannot register it on the session which is most likely the root cause of the error. Take a look at documentation for details on how to configure it.

           

          HTH

          • 2. Re: Error starting process instance - getting  HTTP 500: Unknown error
            Senthil Sathiya Newbie

            Hi Maciej,

             

            Thanks for your reply. I went through the documentation and followed the steps . First , created a sampleprocess.bpmn with - start --->  task (CustomHandler) -> and end event .

             

            2) Wrote a CustomHandler.java workItem handler class

             

            package com.sample.bpmn.project;

             

            import org.apache.log4j.Logger;

            import org.drools.runtime.process.WorkItemHandler;

            import org.drools.runtime.process.WorkItem;

            import org.drools.runtime.process.WorkItemManager;

             

             

             

            public class CustomHandler implements WorkItemHandler {

               static Logger log = Logger.getLogger(

                        CustomHandler.class.getName());

             

                //@Override

             

                public void abortWorkItem(WorkItem workItem, WorkItemManager manager) {       

                    // extract parameters       

                  System.out.println("aborting *****");

                }

             

             

                //@Override

             

                public void executeWorkItem(WorkItem workItem, WorkItemManager manager) {

             

                   System.out.println("The custom work handler is successfully invoked");     

                   log.info("The custom work handler is successfully invoked");

                   manager.completeWorkItem(workItem.getId(), null);

             

             

                }

             

             

            }

             

            and packaged it into a .jar and  copied it into ..\jboss-as-7.1.1.Final\standalone\deployments\jbpm-gwt-console-server.war\WEB-INF\lib\  and ..\jbpm-installer\jboss-as-7.1.1.Final\standalone\lib directories.

             

            3) In guvnor, created a workitem defintion CustomWorkItemHandler ( Not sure if this is required )

             

               

            import org.drools.process.core.datatype.impl.type.ObjectDataType;

            import org.drools.process.core.datatype.impl.type.StringDataType;

             

            [

             

              [

                "name" : "CustomHandler",

                "parameters" : [

                    "MyFirstParam" : new StringDataType(),

                    "MySecondParam" : new StringDataType(),

                    "MyThirdParam" : new ObjectDataType()

                ],

                "results" : [

                    "Result" : new ObjectDataType()

                ],

                "displayName" : "CustomHandler",

                "icon" : "",

              ]

                

            ]

             

            Successfully packaged and deployed the sampleprocess and wid into the GWT console server via guvnor.

             

             

            4) Modified the CustomWorkItemHandlers.conf file and added the following entry

             

            [

              "Log": new org.jbpm.process.instance.impl.demo.SystemOutWorkItemHandler(), 

            "CustomHandler": new com.sample.bpmn.project.CustomHandler(),

            ]

             

            5) Restarted the server . I was able to see the SampleProcess in the webconsole , but when I tried to start it , blew up again with the same error message .

             

            I am really frustrated , not sure what I am missing here. . Any help would be highly appreciated .

             

            Thanks

             

            Senthil

            • 3. Re: Error starting process instance - getting  HTTP 500: Unknown error
              Maciej Swiderski Master

              Step 2, it's enough to place it in jbpm-gwt-console-server.war\WEB-INF\lib

              Step 3 is not really needed for runtime.

               

              where is this file (CustomWorkItemHandlers.conf) located? If you look at 5.4 documentation and the link I placed previously you'll notice that there is something called session.template that can be used to configure handlers as well.

              In server.log you should see more details about the error.

               

              HTH

              1 of 1 people found this helpful
              • 4. Re: Error starting process instance - getting  HTTP 500: Unknown error
                Senthil Sathiya Newbie

                Thanks for your reply . The CustomWorkItemHandlers.conf file is located within the jboss-as-7.1.1.Final\standalone\deployments\jbpm-gwt-console-server.war\WEB-INF\classes\META-INF\ directory . Let me try modifying the session.template and see if that works . I will get back to you after making the changes .

                 

                Thanks again