franco80 [https://community.jboss.org/people/franco80] created the discussion "Could not commit session: java.lang.NullPointerException after start process, start task and complete task in one method" To view the discussion, visit: https://community.jboss.org/message/787295#787295 -------------------------------------------------------------- Hello all, (Jbpm 5.3, JPA2, Jboss 7.1.1) sometimes I get an exception when create a process, start a task, and the task is completed. The whole is carried out in a single method. Any ideas what is wrong  ? Code with null pointer:                public Process getProcess() {                        if (this.process == null) { line 67 -->                this.process = kruntime.getKnowledgeBase().getProcess(processId);                        }                        return this.process;               } 11:03:22,889 ERROR [org.drools.persistence.SingleSessionCommandService] (NioProcessor-4) Could not commit session: java.lang.NullPointerException     at org.jbpm.process.instance.impl.ProcessInstanceImpl.getProcess(ProcessInstanceImpl.java:67) [jbpm-flow-5.3.0.Final.jar:5.3.0.Final]     at org.jbpm.workflow.instance.impl.WorkflowProcessInstanceImpl.getWorkflowProcess(WorkflowProcessInstanceImpl.java:181) [jbpm-flow-5.3.0.Final.jar:5.3.0.Final]     at org.jbpm.workflow.instance.impl.WorkflowProcessInstanceImpl.getNodeContainer(WorkflowProcessInstanceImpl.java:69) [jbpm-flow-5.3.0.Final.jar:5.3.0.Final]     at org.jbpm.workflow.instance.impl.NodeInstanceImpl.getNode(NodeInstanceImpl.java:101) [jbpm-flow-5.3.0.Final.jar:5.3.0.Final]     at org.jbpm.workflow.instance.impl.NodeInstanceImpl.resolveContext(NodeInstanceImpl.java:217) [jbpm-flow-5.3.0.Final.jar:5.3.0.Final]     at org.jbpm.workflow.instance.impl.NodeInstanceImpl.resolveContextInstance(NodeInstanceImpl.java:221) [jbpm-flow-5.3.0.Final.jar:5.3.0.Final]     at org.jbpm.workflow.instance.node.WorkItemNodeInstance.triggerCompleted(WorkItemNodeInstance.java:206) [jbpm-flow-5.3.0.Final.jar:5.3.0.Final]     at org.jbpm.workflow.instance.node.HumanTaskNodeInstance.triggerCompleted(HumanTaskNodeInstance.java:90) [jbpm-flow-5.3.0.Final.jar:5.3.0.Final]     at org.jbpm.workflow.instance.node.WorkItemNodeInstance.workItemCompleted(WorkItemNodeInstance.java:301) [jbpm-flow-5.3.0.Final.jar:5.3.0.Final]     at org.jbpm.workflow.instance.node.WorkItemNodeInstance.signalEvent(WorkItemNodeInstance.java:277) [jbpm-flow-5.3.0.Final.jar:5.3.0.Final]     at org.jbpm.workflow.instance.impl.WorkflowProcessInstanceImpl.signalEvent(WorkflowProcessInstanceImpl.java:326) [jbpm-flow-5.3.0.Final.jar:5.3.0.Final]     at org.drools.persistence.jpa.processinstance.JPAWorkItemManager.completeWorkItem(JPAWorkItemManager.java:121) [drools-persistence-jpa-5.4.0.Final.jar:5.4.0.Final]     at org.drools.command.runtime.process.CompleteWorkItemCommand.execute(CompleteWorkItemCommand.java:69) [drools-core-5.4.0.Final.jar:5.4.0.Final]     at org.drools.command.runtime.process.CompleteWorkItemCommand.execute(CompleteWorkItemCommand.java:32) [drools-core-5.4.0.Final.jar:5.4.0.Final]     at org.drools.command.impl.DefaultCommandService.execute(DefaultCommandService.java:36) [drools-core-5.4.0.Final.jar:5.4.0.Final]     at org.drools.persistence.SingleSessionCommandService.execute(SingleSessionCommandService.java:367) [drools-persistence-jpa-5.4.0.Final.jar:5.4.0.Final]     at org.drools.command.impl.CommandBasedStatefulKnowledgeSession$1.completeWorkItem(CommandBasedStatefulKnowledgeSession.java:150) [drools-core-5.4.0.Final.jar:5.4.0.Final]     at org.jbpm.process.workitem.wsht.CommandBasedWSHumanTaskHandler$GetResultContentResponseHandler.execute(CommandBasedWSHumanTaskHandler.java:364) [jbpm-human-task-mina-5.3.0.Final.jar:5.3.0.Final]     at org.jbpm.task.service.TaskClientHandler.messageReceived(TaskClientHandler.java:153) [jbpm-human-task-core-5.3.0.Final.jar:5.3.0.Final]     at org.jbpm.task.service.mina.MinaTaskClientHandler.messageReceived(MinaTaskClientHandler.java:47) [jbpm-human-task-mina-5.3.0.Final.jar:5.3.0.Final]     at org.apache.mina.core.filterchain.DefaultIoFilterChain$TailFilter.messageReceived(DefaultIoFilterChain.java:713) [mina-core-2.0.0-RC1.jar:]     at org.apache.mina.core.filterchain.DefaultIoFilterChain.callNextMessageReceived(DefaultIoFilterChain.java:434) [mina-core-2.0.0-RC1.jar:]     at org.apache.mina.core.filterchain.DefaultIoFilterChain.access$1200(DefaultIoFilterChain.java:46) [mina-core-2.0.0-RC1.jar:]     at org.apache.mina.core.filterchain.DefaultIoFilterChain$EntryImpl$1.messageReceived(DefaultIoFilterChain.java:793) [mina-core-2.0.0-RC1.jar:]     at org.apache.mina.filter.codec.ProtocolCodecFilter$ProtocolDecoderOutputImpl.flush(ProtocolCodecFilter.java:375) [mina-core-2.0.0-RC1.jar:]     at org.apache.mina.filter.codec.ProtocolCodecFilter.messageReceived(ProtocolCodecFilter.java:229) [mina-core-2.0.0-RC1.jar:]     at org.apache.mina.core.filterchain.DefaultIoFilterChain.callNextMessageReceived(DefaultIoFilterChain.java:434) [mina-core-2.0.0-RC1.jar:]     at org.apache.mina.core.filterchain.DefaultIoFilterChain.access$1200(DefaultIoFilterChain.java:46) [mina-core-2.0.0-RC1.jar:]     at org.apache.mina.core.filterchain.DefaultIoFilterChain$EntryImpl$1.messageReceived(DefaultIoFilterChain.java:793) [mina-core-2.0.0-RC1.jar:]     at org.apache.mina.core.filterchain.IoFilterAdapter.messageReceived(IoFilterAdapter.java:119) [mina-core-2.0.0-RC1.jar:]     at org.apache.mina.core.filterchain.DefaultIoFilterChain.callNextMessageReceived(DefaultIoFilterChain.java:434) [mina-core-2.0.0-RC1.jar:]     at org.apache.mina.core.filterchain.DefaultIoFilterChain.fireMessageReceived(DefaultIoFilterChain.java:426) [mina-core-2.0.0-RC1.jar:]     at org.apache.mina.core.polling.AbstractPollingIoProcessor.read(AbstractPollingIoProcessor.java:638) [mina-core-2.0.0-RC1.jar:]     at org.apache.mina.core.polling.AbstractPollingIoProcessor.process(AbstractPollingIoProcessor.java:598) [mina-core-2.0.0-RC1.jar:]     at org.apache.mina.core.polling.AbstractPollingIoProcessor.process(AbstractPollingIoProcessor.java:587) [mina-core-2.0.0-RC1.jar:]     at org.apache.mina.core.polling.AbstractPollingIoProcessor.access$400(AbstractPollingIoProcessor.java:61) [mina-core-2.0.0-RC1.jar:]     at org.apache.mina.core.polling.AbstractPollingIoProcessor$Processor.run(AbstractPollingIoProcessor.java:969) [mina-core-2.0.0-RC1.jar:]     at org.apache.mina.util.NamePreservingRunnable.run(NamePreservingRunnable.java:64) [mina-core-2.0.0-RC1.jar:]     at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1110) [rt.jar:1.7.0_09]     at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:603) [rt.jar:1.7.0_09]     at java.lang.Thread.run(Thread.java:722) [rt.jar:1.7.0_09] 11:03:23,254 ERROR [stderr] (NioProcessor-4) java.lang.NullPointerException 11:03:23,255 ERROR [stderr] (NioProcessor-4)     at org.jbpm.process.instance.impl.ProcessInstanceImpl.getProcess(ProcessInstanceImpl.java:67) 11:03:23,256 ERROR [stderr] (NioProcessor-4)     at org.jbpm.workflow.instance.impl.WorkflowProcessInstanceImpl.getWorkflowProcess(WorkflowProcessInstanceImpl.java:181) 11:03:23,257 ERROR [stderr] (NioProcessor-4)     at org.jbpm.workflow.instance.impl.WorkflowProcessInstanceImpl.getNodeContainer(WorkflowProcessInstanceImpl.java:69) 11:03:23,257 ERROR [stderr] (NioProcessor-4)     at org.jbpm.workflow.instance.impl.NodeInstanceImpl.getNode(NodeInstanceImpl.java:101) 11:03:23,258 ERROR [stderr] (NioProcessor-4)     at org.jbpm.workflow.instance.impl.NodeInstanceImpl.resolveContext(NodeInstanceImpl.java:217) 11:03:23,259 ERROR [stderr] (NioProcessor-4)     at org.jbpm.workflow.instance.impl.NodeInstanceImpl.resolveContextInstance(NodeInstanceImpl.java:221) 11:03:23,260 ERROR [stderr] (NioProcessor-4)     at org.jbpm.workflow.instance.node.WorkItemNodeInstance.triggerCompleted(WorkItemNodeInstance.java:206) 11:03:23,261 ERROR [stderr] (NioProcessor-4)     at org.jbpm.workflow.instance.node.HumanTaskNodeInstance.triggerCompleted(HumanTaskNodeInstance.java:90) 11:03:23,262 ERROR [stderr] (NioProcessor-4)     at org.jbpm.workflow.instance.node.WorkItemNodeInstance.workItemCompleted(WorkItemNodeInstance.java:301) 11:03:23,263 ERROR [stderr] (NioProcessor-4)     at org.jbpm.workflow.instance.node.WorkItemNodeInstance.signalEvent(WorkItemNodeInstance.java:277) 11:03:23,264 ERROR [stderr] (NioProcessor-4)     at org.jbpm.workflow.instance.impl.WorkflowProcessInstanceImpl.signalEvent(WorkflowProcessInstanceImpl.java:326) 11:03:23,265 ERROR [stderr] (NioProcessor-4)     at org.drools.persistence.jpa.processinstance.JPAWorkItemManager.completeWorkItem(JPAWorkItemManager.java:121) 11:03:23,266 ERROR [stderr] (NioProcessor-4)     at org.drools.command.runtime.process.CompleteWorkItemCommand.execute(CompleteWorkItemCommand.java:69) 11:03:23,267 ERROR [stderr] (NioProcessor-4)     at org.drools.command.runtime.process.CompleteWorkItemCommand.execute(CompleteWorkItemCommand.java:32) 11:03:23,267 ERROR [stderr] (NioProcessor-4)     at org.drools.command.impl.DefaultCommandService.execute(DefaultCommandService.java:36) 11:03:23,268 ERROR [stderr] (NioProcessor-4)     at org.drools.persistence.SingleSessionCommandService.execute(SingleSessionCommandService.java:367) 11:03:23,269 ERROR [stderr] (NioProcessor-4)     at org.drools.command.impl.CommandBasedStatefulKnowledgeSession$1.completeWorkItem(CommandBasedStatefulKnowledgeSession.java:150) 11:03:23,270 ERROR [stderr] (NioProcessor-4)     at org.jbpm.process.workitem.wsht.CommandBasedWSHumanTaskHandler$GetResultContentResponseHandler.execute(CommandBasedWSHumanTaskHandler.java:364) 11:03:23,271 ERROR [stderr] (NioProcessor-4)     at org.jbpm.task.service.TaskClientHandler.messageReceived(TaskClientHandler.java:153) 11:03:23,272 ERROR [stderr] (NioProcessor-4)     at org.jbpm.task.service.mina.MinaTaskClientHandler.messageReceived(MinaTaskClientHandler.java:47) 11:03:23,273 ERROR [stderr] (NioProcessor-4)     at org.apache.mina.core.filterchain.DefaultIoFilterChain$TailFilter.messageReceived(DefaultIoFilterChain.java:713) 11:03:23,274 ERROR [stderr] (NioProcessor-4)     at org.apache.mina.core.filterchain.DefaultIoFilterChain.callNextMessageReceived(DefaultIoFilterChain.java:434) 11:03:23,275 ERROR [stderr] (NioProcessor-4)     at org.apache.mina.core.filterchain.DefaultIoFilterChain.access$1200(DefaultIoFilterChain.java:46) 11:03:23,276 ERROR [stderr] (NioProcessor-4)     at org.apache.mina.core.filterchain.DefaultIoFilterChain$EntryImpl$1.messageReceived(DefaultIoFilterChain.java:793) 11:03:23,277 ERROR [stderr] (NioProcessor-4)     at org.apache.mina.filter.codec.ProtocolCodecFilter$ProtocolDecoderOutputImpl.flush(ProtocolCodecFilter.java:375) 11:03:23,278 ERROR [stderr] (NioProcessor-4)     at org.apache.mina.filter.codec.ProtocolCodecFilter.messageReceived(ProtocolCodecFilter.java:229) 11:03:23,279 ERROR [stderr] (NioProcessor-4)     at org.apache.mina.core.filterchain.DefaultIoFilterChain.callNextMessageReceived(DefaultIoFilterChain.java:434) 11:03:23,280 ERROR [stderr] (NioProcessor-4)     at org.apache.mina.core.filterchain.DefaultIoFilterChain.access$1200(DefaultIoFilterChain.java:46) 11:03:23,281 ERROR [stderr] (NioProcessor-4)     at org.apache.mina.core.filterchain.DefaultIoFilterChain$EntryImpl$1.messageReceived(DefaultIoFilterChain.java:793) 11:03:23,282 ERROR [stderr] (NioProcessor-4)     at org.apache.mina.core.filterchain.IoFilterAdapter.messageReceived(IoFilterAdapter.java:119) 11:03:23,283 ERROR [stderr] (NioProcessor-4)     at org.apache.mina.core.filterchain.DefaultIoFilterChain.callNextMessageReceived(DefaultIoFilterChain.java:434) 11:03:23,284 ERROR [stderr] (NioProcessor-4)     at org.apache.mina.core.filterchain.DefaultIoFilterChain.fireMessageReceived(DefaultIoFilterChain.java:426) 11:03:23,285 ERROR [stderr] (NioProcessor-4)     at org.apache.mina.core.polling.AbstractPollingIoProcessor.read(AbstractPollingIoProcessor.java:638) 11:03:23,285 ERROR [stderr] (NioProcessor-4)     at org.apache.mina.core.polling.AbstractPollingIoProcessor.process(AbstractPollingIoProcessor.java:598) 11:03:23,286 ERROR [stderr] (NioProcessor-4)     at org.apache.mina.core.polling.AbstractPollingIoProcessor.process(AbstractPollingIoProcessor.java:587) 11:03:23,287 ERROR [stderr] (NioProcessor-4)     at org.apache.mina.core.polling.AbstractPollingIoProcessor.access$400(AbstractPollingIoProcessor.java:61) 11:03:23,288 ERROR [stderr] (NioProcessor-4)     at org.apache.mina.core.polling.AbstractPollingIoProcessor$Processor.run(AbstractPollingIoProcessor.java:969) 11:03:23,289 ERROR [stderr] (NioProcessor-4)     at org.apache.mina.util.NamePreservingRunnable.run(NamePreservingRunnable.java:64) 11:03:23,290 ERROR [stderr] (NioProcessor-4)     at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1110) 11:03:23,290 ERROR [stderr] (NioProcessor-4)     at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:603) 11:03:23,291 ERROR [stderr] (NioProcessor-4)     at java.lang.Thread.run(Thread.java:722) -------------------------------------------------------------- Reply to this message by going to Community [https://community.jboss.org/message/787295#787295] Start a new discussion in jBPM at Community [https://community.jboss.org/choose-container!input.jspa?contentType=1&...]