Mysterious exception while running a process definition

[malekobaid]

Hallo There,

I newly set up Activiti and designed a process definition. While its running, it hangs without any error on the web interface but I found the following exception trace in catalina log file.
I hope somebody can help.


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Mai 26, 2014 2:03:13 PM org.restlet.resource.ServerResource doCatch
Warnung: Exception or error caught in server resource
Internal Server Error (500) - The server encountered an unexpected condition which prevented it from fulfilling the request
   at org.restlet.resource.ServerResource.doHandle(ServerResource.java:517)
   at org.restlet.resource.ServerResource.get(ServerResource.java:707)
   at org.restlet.resource.ServerResource.doHandle(ServerResource.java:589)
   at org.restlet.resource.ServerResource.doNegotiatedHandle(ServerResource.java:649)
   at org.restlet.resource.ServerResource.doConditionalHandle(ServerResource.java:348)
   at org.restlet.resource.ServerResource.handle(ServerResource.java:952)
   at org.restlet.resource.Finder.handle(Finder.java:246)
   at org.restlet.routing.Filter.doHandle(Filter.java:159)
   at org.restlet.routing.Filter.handle(Filter.java:206)
   at org.restlet.routing.Router.doHandle(Router.java:431)
   at org.restlet.routing.Router.handle(Router.java:648)
   at org.restlet.routing.Filter.doHandle(Filter.java:159)
   at org.restlet.routing.Filter.handle(Filter.java:206)
   at org.restlet.routing.Filter.doHandle(Filter.java:159)
   at org.restlet.routing.Filter.handle(Filter.java:206)
   at org.restlet.routing.Filter.doHandle(Filter.java:159)
   at org.restlet.routing.Filter.handle(Filter.java:206)
   at org.restlet.routing.Filter.doHandle(Filter.java:159)
   at org.restlet.engine.application.StatusFilter.doHandle(StatusFilter.java:155)
   at org.restlet.routing.Filter.handle(Filter.java:206)
   at org.restlet.routing.Filter.doHandle(Filter.java:159)
   at org.restlet.routing.Filter.handle(Filter.java:206)
   at org.restlet.engine.CompositeHelper.handle(CompositeHelper.java:211)
   at org.restlet.engine.application.ApplicationHelper.handle(ApplicationHelper.java:84)
   at org.restlet.Application.handle(Application.java:381)
   at org.restlet.routing.Filter.doHandle(Filter.java:159)
   at org.restlet.routing.Filter.handle(Filter.java:206)
   at org.restlet.routing.Router.doHandle(Router.java:431)
   at org.restlet.routing.Router.handle(Router.java:648)
   at org.restlet.routing.Filter.doHandle(Filter.java:159)
   at org.restlet.routing.Filter.handle(Filter.java:206)
   at org.restlet.routing.Router.doHandle(Router.java:431)
   at org.restlet.routing.Router.handle(Router.java:648)
   at org.restlet.routing.Filter.doHandle(Filter.java:159)
   at org.restlet.routing.Filter.handle(Filter.java:206)
   at org.restlet.engine.CompositeHelper.handle(CompositeHelper.java:211)
   at org.restlet.Component.handle(Component.java:392)
   at org.restlet.Server.handle(Server.java:516)
   at org.restlet.engine.ServerHelper.handle(ServerHelper.java:72)
   at org.restlet.engine.adapter.HttpServerHelper.handle(HttpServerHelper.java:152)
   at org.restlet.ext.servlet.ServerServlet.service(ServerServlet.java:1089)
   at javax.servlet.http.HttpServlet.service(HttpServlet.java:728)
   at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:305)
   at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:210)
   at org.activiti.explorer.filter.ExplorerFilter.doFilter(ExplorerFilter.java:44)
   at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:243)
   at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:210)
   at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:222)
   at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:123)
   at org.apache.catalina.authenticator.AuthenticatorBase.invoke(AuthenticatorBase.java:502)
   at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:171)
   at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:99)
   at org.apache.catalina.valves.AccessLogValve.invoke(AccessLogValve.java:953)
   at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:118)
   at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:408)
   at org.apache.coyote.http11.AbstractHttp11Processor.process(AbstractHttp11Processor.java:1023)
   at org.apache.coyote.AbstractProtocol$AbstractConnectionHandler.process(AbstractProtocol.java:589)
   at org.apache.tomcat.util.net.AprEndpoint$SocketProcessor.run(AprEndpoint.java:1852)
   at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1145)
   at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:615)
   at java.lang.Thread.run(Thread.java:744)
Caused by: java.lang.NullPointerException
   at org.activiti.rest.diagram.services.ProcessDefinitionDiagramLayoutResource.getActivity(ProcessDefinitionDiagramLayoutResource.java:440)
   at org.activiti.rest.diagram.services.ProcessDefinitionDiagramLayoutResource.getDiagram(ProcessDefinitionDiagramLayoutResource.java:203)
   at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
   at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:57)
   at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
   at java.lang.reflect.Method.invoke(Method.java:606)
   at org.restlet.resource.ServerResource.doHandle(ServerResource.java:506)
   … 60 more


I suspect it has something to do when an activity is trying to call something in the java classes. Although the jar is added.
It is kind of a complex process definition, so can somebody have/get an idea what the previous exception could ever mean?

thanks in advance

[martin_grofcik]

Hi

What I have found in the source:

          // TODO: unuseful fields there are processDefinitionName,
          // processDefinitionKey
          ObjectNode processInstanceJSON = new ObjectMapper().createObjectNode();
          processInstanceJSON.put("processDefinitionId", lastProcessDefinition.getId());
          processInstanceJSON.put("processDefinitionKey", lastProcessDefinition.getKey());
        processInstanceJSON.put("processDefinitionId", lastProcessDefinition.getId());
null could be processInstanceJSON, lastProcessDefinition.
THe esiest way how to reproduce this error is to create jUnit test. (Or you can debug it too)

Regards
Martin