taskService.deleteTaskAttachment inside multi-instance fails in 7.20

Camunda 7 Topics
1

In 7.17 inside a multi-instance block I have a UserTask in which I upload a file. Then, I use the code in the attached image to remove the file.

In Camunda 7.20 the same doesn’t work, due to this:

org.camunda.bpm.engine.ScriptEvaluationException: Unable to evaluate script while executing activity ‘Remove_attachments’ in the process definition with id ‘file-removal:7:5eab991a-cccd-11ee-b858-02a0d249c658’: java.lang.NullPointerException: Cannot invoke “org.camunda.bpm.engine.impl.persistence.entity.TaskEntity.triggerUpdateEvent()” because “task” is null

Screenshot 2024-02-16 160931
Screenshot 2024-02-16 1609311210×486 28.9 KB

2

The file removal works if the multi-instance exclusivity is left out. But the exclusivity is needed in the process. But it causes the above described problem.

3

Hi @xqats,

Could you please share the compete stacktrace of the exception?
Is it possible to share a minimal example that reproduces the issue? (You can use this project as a template: GitHub - camunda/camunda-engine-unittest: Unit test template project for camunda engine)

Best regards,
Yana

1 Like
4

Hi @Yana, thanks a lot for the reply. This is easily re-producable.
Simply have a multi-instance block looping over an array. See attached image. Turn on async continuations on the MI-block, the UserTask and the ScriptTask.

Inside the block, upload an attachment to the UserTask. In next step, remove the attachment, with the groovy code of my first message in this thread.

That is the need we have. In our real process, we upload a file from disk to a 3rd system. As the file passes by Camunda on its way, we wish to later remove it from Camunda. Not to have the db fill up, and simply because the file doesn’t belong in Camunda.

image
image880×294 8.18 KB

5

@Yana stacktrace here:

org.camunda.bpm.engine.ScriptEvaluationException: Unable to evaluate script while executing activity ‘Remove_attachments’ in the process definition with id ‘file-removal:7:5eab991a-cccd-11ee-b858-02a0d249c658’: java.lang.NullPointerException: Cannot invoke “org.camunda.bpm.engine.impl.persistence.entity.TaskEntity.triggerUpdateEvent()” because “task” is null

at org.camunda.bpm.engine.impl.scripting.CompiledExecutableScript.evaluate(CompiledExecutableScript.java:61)

at org.camunda.bpm.engine.impl.scripting.SourceExecutableScript.evaluate(SourceExecutableScript.java:61)

at org.camunda.bpm.engine.impl.scripting.ResourceExecutableScript.evaluate(ResourceExecutableScript.java:46)

at org.camunda.bpm.engine.impl.scripting.ExecutableScript.execute(ExecutableScript.java:63)

at org.camunda.bpm.engine.impl.scripting.env.ScriptingEnvironment.execute(ScriptingEnvironment.java:99)

at org.camunda.bpm.engine.impl.scripting.env.ScriptingEnvironment.execute(ScriptingEnvironment.java:87)

at org.camunda.bpm.engine.impl.delegate.ScriptInvocation.invoke(ScriptInvocation.java:47)

at org.camunda.bpm.engine.impl.delegate.DelegateInvocation.proceed(DelegateInvocation.java:58)

at org.camunda.bpm.engine.impl.delegate.DefaultDelegateInterceptor.handleInvocationInContext(DefaultDelegateInterceptor.java:92)

at org.camunda.bpm.engine.impl.delegate.DefaultDelegateInterceptor.handleInvocation(DefaultDelegateInterceptor.java:63)

at org.camunda.bpm.engine.impl.bpmn.behavior.ScriptTaskActivityBehavior$1.call(ScriptTaskActivityBehavior.java:55)

at org.camunda.bpm.engine.impl.bpmn.behavior.ScriptTaskActivityBehavior$1.call(ScriptTaskActivityBehavior.java:51)

at org.camunda.bpm.engine.impl.bpmn.behavior.AbstractBpmnActivityBehavior.executeWithErrorPropagation(AbstractBpmnActivityBehavior.java:90)

at org.camunda.bpm.engine.impl.bpmn.behavior.ScriptTaskActivityBehavior.performExecution(ScriptTaskActivityBehavior.java:51)

at org.camunda.bpm.engine.impl.bpmn.behavior.TaskActivityBehavior.execute(TaskActivityBehavior.java:69)

at org.camunda.bpm.engine.impl.pvm.runtime.operation.PvmAtomicOperationActivityExecute$2.callback(PvmAtomicOperationActivityExecute.java:61)

at org.camunda.bpm.engine.impl.pvm.runtime.operation.PvmAtomicOperationActivityExecute$2.callback(PvmAtomicOperationActivityExecute.java:50)

at org.camunda.bpm.engine.impl.pvm.runtime.PvmExecutionImpl.continueIfExecutionDoesNotAffectNextOperation(PvmExecutionImpl.java:2082)

at org.camunda.bpm.engine.impl.pvm.runtime.operation.PvmAtomicOperationActivityExecute.execute(PvmAtomicOperationActivityExecute.java:42)

at org.camunda.bpm.engine.impl.pvm.runtime.operation.PvmAtomicOperationActivityExecute.execute(PvmAtomicOperationActivityExecute.java:31)

at org.camunda.bpm.engine.impl.interceptor.AtomicOperationInvocation.execute(AtomicOperationInvocation.java:99)

at org.camunda.bpm.engine.impl.interceptor.CommandInvocationContext.invokeNext(CommandInvocationContext.java:130)

at org.camunda.bpm.engine.impl.interceptor.CommandInvocationContext.performNext(CommandInvocationContext.java:110)

at org.camunda.bpm.engine.impl.interceptor.CommandInvocationContext.performOperation(CommandInvocationContext.java:85)

at org.camunda.bpm.engine.impl.persistence.entity.ExecutionEntity.performOperation(ExecutionEntity.java:622)

at org.camunda.bpm.engine.impl.persistence.entity.ExecutionEntity.performOperation(ExecutionEntity.java:596)

at org.camunda.bpm.engine.impl.pvm.runtime.PvmExecutionImpl$6.callback(PvmExecutionImpl.java:2021)

at org.camunda.bpm.engine.impl.pvm.runtime.PvmExecutionImpl$6.callback(PvmExecutionImpl.java:2018)

at org.camunda.bpm.engine.impl.pvm.runtime.PvmExecutionImpl.continueExecutionIfNotCanceled(PvmExecutionImpl.java:2088)

at org.camunda.bpm.engine.impl.pvm.runtime.PvmExecutionImpl.dispatchDelayedEventsAndPerformOperation(PvmExecutionImpl.java:2037)

at org.camunda.bpm.engine.impl.pvm.runtime.PvmExecutionImpl.dispatchDelayedEventsAndPerformOperation(PvmExecutionImpl.java:2018)

at org.camunda.bpm.engine.impl.pvm.runtime.operation.PvmAtomicOperationTransitionNotifyListenerStart.eventNotificationsCompleted(PvmAtomicOperationTransitionNotifyListenerStart.java:61)

at org.camunda.bpm.engine.impl.pvm.runtime.operation.PvmAtomicOperationTransitionNotifyListenerStart.eventNotificationsCompleted(PvmAtomicOperationTransitionNotifyListenerStart.java:30)

at org.camunda.bpm.engine.impl.core.operation.AbstractEventAtomicOperation.execute(AbstractEventAtomicOperation.java:70)

at org.camunda.bpm.engine.impl.interceptor.AtomicOperationInvocation.execute(AtomicOperationInvocation.java:99)

at org.camunda.bpm.engine.impl.interceptor.CommandInvocationContext.invokeNext(CommandInvocationContext.java:130)

at org.camunda.bpm.engine.impl.interceptor.CommandInvocationContext.performNext(CommandInvocationContext.java:110)

at org.camunda.bpm.engine.impl.interceptor.CommandInvocationContext.performOperation(CommandInvocationContext.java:85)

at org.camunda.bpm.engine.impl.interceptor.CommandInvocationContext.performOperation(CommandInvocationContext.java:75)

at org.camunda.bpm.engine.impl.persistence.entity.ExecutionEntity.performOperationSync(ExecutionEntity.java:631)

at org.camunda.bpm.engine.impl.persistence.entity.ExecutionEntity.performOperationSync(ExecutionEntity.java:606)

at org.camunda.bpm.engine.impl.core.operation.AbstractEventAtomicOperation.execute(AbstractEventAtomicOperation.java:66)

at org.camunda.bpm.engine.impl.interceptor.AtomicOperationInvocation.execute(AtomicOperationInvocation.java:99)

at org.camunda.bpm.engine.impl.interceptor.CommandInvocationContext.invokeNext(CommandInvocationContext.java:130)

at org.camunda.bpm.engine.impl.interceptor.CommandInvocationContext.performNext(CommandInvocationContext.java:110)

at org.camunda.bpm.engine.impl.interceptor.CommandInvocationContext.performOperation(CommandInvocationContext.java:85)

at org.camunda.bpm.engine.impl.interceptor.CommandInvocationContext.performOperation(CommandInvocationContext.java:75)

at org.camunda.bpm.engine.impl.persistence.entity.ExecutionEntity.performOperationSync(ExecutionEntity.java:631)

at org.camunda.bpm.engine.impl.persistence.entity.ExecutionEntity.performOperationSync(ExecutionEntity.java:606)

at org.camunda.bpm.engine.impl.core.operation.AbstractEventAtomicOperation.execute(AbstractEventAtomicOperation.java:66)

at org.camunda.bpm.engine.impl.interceptor.AtomicOperationInvocation.execute(AtomicOperationInvocation.java:99)

at org.camunda.bpm.engine.impl.interceptor.CommandInvocationContext.invokeNext(CommandInvocationContext.java:130)

at org.camunda.bpm.engine.impl.interceptor.CommandInvocationContext.performNext(CommandInvocationContext.java:110)

at org.camunda.bpm.engine.impl.interceptor.CommandInvocationContext.performOperation(CommandInvocationContext.java:85)

at org.camunda.bpm.engine.impl.interceptor.CommandInvocationContext.performOperation(CommandInvocationContext.java:75)

at org.camunda.bpm.engine.impl.persistence.entity.ExecutionEntity.performOperationSync(ExecutionEntity.java:631)

at org.camunda.bpm.engine.impl.persistence.entity.ExecutionEntity.performOperationSync(ExecutionEntity.java:606)

at org.camunda.bpm.engine.impl.core.operation.AbstractEventAtomicOperation.execute(AbstractEventAtomicOperation.java:66)

at org.camunda.bpm.engine.impl.interceptor.AtomicOperationInvocation.execute(AtomicOperationInvocation.java:99)

at org.camunda.bpm.engine.impl.interceptor.CommandInvocationContext.invokeNext(CommandInvocationContext.java:130)

at org.camunda.bpm.engine.impl.interceptor.CommandInvocationContext.performNext(CommandInvocationContext.java:110)

at org.camunda.bpm.engine.impl.interceptor.CommandInvocationContext.performOperation(CommandInvocationContext.java:85)

at org.camunda.bpm.engine.impl.persistence.entity.ExecutionEntity.performOperation(ExecutionEntity.java:622)

at org.camunda.bpm.engine.impl.persistence.entity.ExecutionEntity.performOperation(ExecutionEntity.java:596)

at org.camunda.bpm.engine.impl.pvm.runtime.operation.PvmAtomicOperationTransitionCreateScope.scopeCreated(PvmAtomicOperationTransitionCreateScope.java:38)

at org.camunda.bpm.engine.impl.pvm.runtime.operation.PvmAtomicOperationCreateScope.execute(PvmAtomicOperationCreateScope.java:53)

at org.camunda.bpm.engine.impl.pvm.runtime.operation.PvmAtomicOperationCreateScope.execute(PvmAtomicOperationCreateScope.java:27)

at org.camunda.bpm.engine.impl.interceptor.AtomicOperationInvocation.execute(AtomicOperationInvocation.java:99)

at org.camunda.bpm.engine.impl.interceptor.CommandInvocationContext.invokeNext(CommandInvocationContext.java:130)

at org.camunda.bpm.engine.impl.interceptor.CommandInvocationContext.performNext(CommandInvocationContext.java:117)

at org.camunda.bpm.engine.impl.interceptor.CommandInvocationContext.performOperation(CommandInvocationContext.java:85)

at org.camunda.bpm.engine.impl.interceptor.CommandInvocationContext.performOperation(CommandInvocationContext.java:75)

at org.camunda.bpm.engine.impl.jobexecutor.AsyncContinuationJobHandler.execute(AsyncContinuationJobHandler.java:81)

at org.camunda.bpm.engine.impl.jobexecutor.AsyncContinuationJobHandler.execute(AsyncContinuationJobHandler.java:40)

at org.camunda.bpm.engine.impl.persistence.entity.JobEntity.execute(JobEntity.java:133)

at org.camunda.bpm.engine.impl.cmd.ExecuteJobsCmd.execute(ExecuteJobsCmd.java:110)

at org.camunda.bpm.engine.impl.cmd.ExecuteJobsCmd.execute(ExecuteJobsCmd.java:43)

at org.camunda.bpm.engine.impl.interceptor.CommandExecutorImpl.execute(CommandExecutorImpl.java:28)

at org.camunda.bpm.engine.impl.interceptor.CommandContextInterceptor.execute(CommandContextInterceptor.java:110)

at org.camunda.bpm.engine.spring.SpringTransactionInterceptor.lambda$execute$0(SpringTransactionInterceptor.java:71)

at org.springframework.transaction.support.TransactionTemplate.execute(TransactionTemplate.java:140)

at org.camunda.bpm.engine.spring.SpringTransactionInterceptor.execute(SpringTransactionInterceptor.java:71)

at org.camunda.bpm.engine.impl.interceptor.ProcessApplicationContextInterceptor.execute(ProcessApplicationContextInterceptor.java:70)

at org.camunda.bpm.engine.impl.interceptor.CommandCounterInterceptor.execute(CommandCounterInterceptor.java:35)

at org.camunda.bpm.engine.impl.interceptor.LogInterceptor.execute(LogInterceptor.java:33)

at org.camunda.bpm.engine.impl.interceptor.ExceptionCodeInterceptor.execute(ExceptionCodeInterceptor.java:55)

at org.camunda.bpm.engine.impl.jobexecutor.ExecuteJobHelper.executeJob(ExecuteJobHelper.java:57)

at org.camunda.bpm.engine.impl.jobexecutor.ExecuteJobsRunnable.executeJob(ExecuteJobsRunnable.java:110)

at org.camunda.bpm.engine.impl.jobexecutor.ExecuteJobsRunnable.run(ExecuteJobsRunnable.java:71)

at java.base/java.util.concurrent.ThreadPoolExecutor.runWorker(Unknown Source)

at java.base/java.util.concurrent.ThreadPoolExecutor$Worker.run(Unknown Source)

at java.base/java.lang.Thread.run(Unknown Source)
Caused by: javax.script.ScriptException: java.lang.NullPointerException: Cannot invoke “org.camunda.bpm.engine.impl.persistence.entity.TaskEntity.triggerUpdateEvent()” because “task” is null

at org.codehaus.groovy.jsr223.GroovyScriptEngineImpl.eval(GroovyScriptEngineImpl.java:334)

at org.codehaus.groovy.jsr223.GroovyCompiledScript.eval(GroovyCompiledScript.java:72)

at java.scripting/javax.script.CompiledScript.eval(Unknown Source)

at org.camunda.bpm.engine.impl.scripting.CompiledExecutableScript.evaluate(CompiledExecutableScript.java:55)

… 91 common frames omitted
Caused by: java.lang.NullPointerException: Cannot invoke “org.camunda.bpm.engine.impl.persistence.entity.TaskEntity.triggerUpdateEvent()” because “task” is null

at org.camunda.bpm.engine.impl.cmd.DeleteAttachmentCmd.execute(DeleteAttachmentCmd.java:84)

at org.camunda.bpm.engine.impl.interceptor.CommandExecutorImpl.execute(CommandExecutorImpl.java:28)

at org.camunda.bpm.engine.impl.interceptor.CommandContextInterceptor.execute(CommandContextInterceptor.java:110)

at org.camunda.bpm.engine.spring.SpringTransactionInterceptor.lambda$execute$0(SpringTransactionInterceptor.java:71)

at org.springframework.transaction.support.TransactionTemplate.execute(TransactionTemplate.java:140)

at org.camunda.bpm.engine.spring.SpringTransactionInterceptor.execute(SpringTransactionInterceptor.java:71)

at org.camunda.bpm.engine.impl.interceptor.ProcessApplicationContextInterceptor.execute(ProcessApplicationContextInterceptor.java:70)

at org.camunda.bpm.engine.impl.interceptor.CommandCounterInterceptor.execute(CommandCounterInterceptor.java:35)

at org.camunda.bpm.engine.impl.interceptor.LogInterceptor.execute(LogInterceptor.java:33)

at org.camunda.bpm.engine.impl.interceptor.ExceptionCodeInterceptor.execute(ExceptionCodeInterceptor.java:55)

at org.camunda.bpm.engine.impl.TaskServiceImpl.deleteTaskAttachment(TaskServiceImpl.java:420)

at org.codehaus.groovy.vmplugin.v8.IndyInterface.fromCache(IndyInterface.java:321)

at Script61.run(Script61.groovy:14)

at org.codehaus.groovy.jsr223.GroovyScriptEngineImpl.eval(GroovyScriptEngineImpl.java:331)

… 94 common frames omitted

6

Thank you for providing the details.
It’s on my TODO list to reproduce the issue and investigate the failure.

1 Like
7

Hi @xqats,

I was not able to reproduce the issue. I am missing context:

  • What does happen in the Set vars script? Is it relevant to reproduce the issue?
  • What does happen in the Service job task?
  • To which execution the document variable is set to? (retrieved in the Remove attachments)

In order to speed up the investigation, could you please share a minimum example that reproduces the problem?

8

Hi Yana,

here is the process, this is a very simple case and I’ll try to help you reproduce it, it should be fairly straight-forward.

file-removal.bpmn (6.4 KB)

9

…the deleteAttachment.groovy goes here:

import org.camunda.bpm.engine.TaskService;
import java.util.LinkedHashMap;

def document = execution.getVariable(“document”);

TaskService taskService = execution.getProcessEngineServices().getTaskService();
Object attachments = + (taskService.getTaskAttachments(document.prop(“uploadFileTaskId”).stringValue()) ?: );

println document.prop(“uploadFileTaskId”).stringValue()

for (Object attachment : attachments) {
//println attachment.getTaskId()
println attachment.taskId
println attachment
//taskService.deleteTaskAttachment(attachment.getTaskId(), attachment.getId());
taskService.deleteTaskAttachment(attachment.taskId, attachment.id);
}

10
  1. What does happen in the Set vars script? Is it relevant to reproduce the issue?
    see model file
  2. What does happen in the Service job task?

file is uploaded, see model file
3. To which execution the document variable is set to? (retrieved in the Remove attachments)
see model file

11

start - Copy.form (2.7 KB)
upload-software - Copy.form (5.5 KB)

12

@Yana I also uploaded the formio-files. Had to change extension to form to enable upload. Now you have everything needed to easily reproduce this. Thanks a lot, hope to hear from you soon! :slight_smile:

13

any luck? :slight_smile:

14

I was able to reproduce the issue. The relevant bug report can be found here:

In your case, a workaround will be to remove the asynchronous continuation of Remove attachments script task.

Please let me know if you are interested in working on bug fix for the issue.

15

Thank you @Yana!