Error while closing command context java.lang.NullPointerException

Camunda 7 Topics Discussion & Questions
1

Hi All,

I am facing the following error while deploying a process.

Error while closing command context java.lang.NullPointerException

I have uploaded the relevant files.Please advise.

Complete Stacktrace.txt (62.3 KB)
loanApproval.bpmn (3.5 KB)

I implemented same process with some changes i.e. putting the code for querying the process definition and process instances in a separate service task and I get the following error.

Spring Bean invoked now
18-Feb-2019 06:01:33.254 SEVERE [ContainerBackgroundProcessor[StandardEngine[Catalina]]] org.camunda.bpm.engine.impl.interceptor.CommandContext.close Error while closing command context
org.camunda.bpm.engine.ProcessEngineException: Delegate expression {allRunningProcessInstances} did neither resolve to an implementation of interface org.camunda.bpm.engine.impl.pvm.delegate.ActivityBehavior nor interface org.camunda.bpm.engine.delegate.JavaDelegate

I am uploading all the relevant files here.

applicationContext.xml (2.7 KB)
Complete stacktrace New.txt (59.2 KB)
loanApproval.bpmn (4.6 KB)
AllRunningProcessInstances.txt (1.8 KB)
CalculateInterestService.txt (1014 Bytes)
Starter.txt (1.1 KB)

2

Can you share the Code of your CalculateInterestService Class?

You have a nullPointer in this class apparently.

Error while closing command context
java.lang.NullPointerException
at org.camunda.bpm.getstarted.loanapproval.CalculateInterestService.execute(CalculateInterestService.java:40)

Also are you aware that you have a service task in the bpmn model that is not connected to anything?
“Get Processes and Instances”

best
Felix

3

I believe you are following this tutorial for this exercise.
https://docs.camunda.org/get-started/spring/service-task/

Did you follow the all the steps mentioned in the document.

4

Hi Felix,

Thanks for responding to my question.

PFB the code I used in the CalculateInterestService Class.Initially,the code underneath the statement “System.out.println(“Spring Bean invoked now”)” ,was part of a separate service task "Get Processes and Instances”(which i disconnected now) but it did not work so I put this code in a service task which is working but it throws NPE.

/*

  • Copyright © 2014 - 2018 camunda services GmbH and various authors (info@camunda.com)
  • Licensed under the Apache License, Version 2.0 (the “License”);
  • you may not use this file except in compliance with the License.
  • You may obtain a copy of the License at
  • http://www.apache.org/licenses/LICENSE-2.0
  • Unless required by applicable law or agreed to in writing, software
  • distributed under the License is distributed on an “AS IS” BASIS,
  • WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  • See the License for the specific language governing permissions and
  • limitations under the License.
    */
    package org.camunda.bpm.getstarted.loanapproval;

import java.util.List;

import org.camunda.bpm.BpmPlatform;
import org.camunda.bpm.engine.ProcessEngine;
import org.camunda.bpm.engine.RepositoryService;
import org.camunda.bpm.engine.RuntimeService;
import org.camunda.bpm.engine.delegate.DelegateExecution;
import org.camunda.bpm.engine.delegate.JavaDelegate;
import org.camunda.bpm.engine.repository.ProcessDefinition;
import org.camunda.bpm.engine.runtime.ProcessInstance;

public class CalculateInterestService implements JavaDelegate {

public void execute(DelegateExecution delegate) throws Exception {

System.out.println("Spring Bean invoked now");

// TODO Auto-generated method stub
// get process engine and services
ProcessEngine processEngine = BpmPlatform.getDefaultProcessEngine();
RuntimeService runtimeService = processEngine.getRuntimeService();
RepositoryService repositoryService = processEngine.getRepositoryService();

 // query for latest process definition with given name
 ProcessDefinition myProcessDefinition =
     repositoryService.createProcessDefinitionQuery()
         .processDefinitionName("loanApproval")
         .latestVersion()
         .singleResult();
 
 System.out.println("List of myProcessDefinition: "+ myProcessDefinition.toString());

 // list all running/unsuspended instances of the process
 List<ProcessInstance> processInstances =
     runtimeService.createProcessInstanceQuery()
         .processDefinitionId(myProcessDefinition.getId())
         .active() // we only want the unsuspended process instances
         .list();

 System.out.println("List of processInstances: "+ processInstances.toString());

}

}

5

Hi Techavidity,

I followed the same example but then I tried to do some experiments and included a code to query process definitions and process instances and it never worked after that.

I updated my post with the 2 different approaches I followed and both did not work.

Approach 1 : I put my code to query process definitions and process instances in a working system task but it gave me NPE.

Approach 2 : I created a separate system task having that code and it gave me the following error.

Spring Bean invoked now
18-Feb-2019 06:01:33.254 SEVERE [ContainerBackgroundProcessor[StandardEngine[Catalina]]] org.camunda.bpm.engine.impl.interceptor.CommandContext.close Error while closing command context
org.camunda.bpm.engine.ProcessEngineException: Delegate expression {allRunningProcessInstances} did neither resolve to an implementation of interface org.camunda.bpm.engine.impl.pvm.delegate.ActivityBehavior nor interface org.camunda.bpm.engine.delegate.JavaDelegate

Please advise.

Thanks in advance.

6

@felix-mueller any thoughts on my issue?

7

HI @harish2624

one issue that you have is that your second service task “Get Processes and Instances” is missing a $ before the {allRunningProcessInstances} in the DelegateExpression in the BPMN model.

Best
Felix

1 Like
8

@felix-mueller Thanks a lot Felix.in fact,the missing ‘$’ was the culprit. My process is running absolutely fine now.I know,it was a rookie mistake. :slight_smile:

9

Very glad that you were able to solve your problem :slight_smile: :muscle:

10