NPE on variables get from ProcessInstance loaded via ProcessInstanceQuery

[mmaker1234]

Hello Activiti developers,

While executing in Activiti 5.13<java start="488" fancy="6">  ProcessInstance process = runtimeService.createProcessInstanceQuery()
                                    .processInstanceId( "1234" )
                                    .includeProcessVariables()
                                    .singleResult();
  if( process != null ) {
    Map<String, Object> vars = process.getProcessVariables(); //Throws NPE in ByteArrayRef.java:94
    …
  }</java>I observe the following error

java.lang.NullPointerException
    at org.activiti.engine.impl.persistence.entity.ByteArrayRef.ensureInitialized(ByteArrayRef.java:94)
    at org.activiti.engine.impl.persistence.entity.ByteArrayRef.getBytes(ByteArrayRef.java:45)
    at org.activiti.engine.impl.persistence.entity.VariableInstanceEntity.getBytes(VariableInstanceEntity.java:138)
    at org.activiti.engine.impl.variable.ByteArrayType.getValue(ByteArrayType.java:32)
    at org.activiti.engine.impl.variable.SerializableType.getValue(SerializableType.java:51)
    at org.activiti.engine.impl.persistence.entity.VariableInstanceEntity.getValue(VariableInstanceEntity.java:165)
    at org.activiti.engine.impl.persistence.entity.ExecutionEntity.getProcessVariables(ExecutionEntity.java:1384)
    at org.activiti.engine.impl.ant.ShowProcessState.formatProcessInstance(ShowProcessState.java:493)
…‍‍‍‍‍‍‍‍‍‍

I tried to debug and found that

Context.getCommandContext()‍

returns

null‍

in

ByteArrayRef.java:94‍

.

A similar code that passes the same row (

ByteArrayRef.java:94‍

) runs fine:<java start="488" fancy="6">  List<Execution> executions = runtimeService.createExecutionQuery()
                                    .processInstanceId( "1234" )
                                    .list();
  if( executions != null ) {
    for (Execution execution : executions) {
      Map<String, Object> globalVars = runtimeService.getVariables( execution.getId() );
      if( globalVars != null ) {
        …
      }
    }
  }</java>

Am I doing something wrong?

[mmaker1234]

Hello,

Isn't there anyone to comment on the above?

[frederikherema1]

Thanks for reporting. Issue has just been fixed on master:

https://jira.codehaus.org/browse/ACT-1731 and https://github.com/Activiti/Activiti/commit/136859b6e4100d80c34bfc5c43964c8c8e4362de.

[erikwinlof]

In case someone wants to follow the github link above (it shouldn't have the trailing ".") click this link instead:
https://github.com/Activiti/Activiti/commit/136859b6e4100d80c34bfc5c43964c8c8e4362de

[mmaker1234]

Thank you, Frederik! 🙂

I'm glad I helped somehow.

[trond_nordli]

I have more or less the same bug in version 5.13 of the REST API, where you do not get the variables on the list of processes.

Works on list of task as expected:
/runtime/tasks?includeProcessVariables = true

Does not work on list of process:
/runtime/process-instances?includeProcessVariables = true

Where you only get blank values ​​"variables": []

Will this error be corrected with the other issue or should this issue be reported separately ?

[frederikherema1]

Should be reported separately, as it's not an exception that is occurring but rather something not working as expected…

[st1]

First of all sorry for my english .
We use version 5.13 and to get list of HistoricVariableInstance we wanted to use NativeHistoricVariableInstanceQuery.

<code>
public List<HistoricVariableInstance> listHistoricVariableInstances(String processInstanceId, Collection<String> variableNames) {
..
StringBuilder query = new StringBuilder();
  query.append("select * from ");
  query.append(managementService.getTableName(HistoricVariableInstance.class));
  query.append(" where  proc_inst_id_ = #{proc_inst_id} and name_ in (");
  query.append(ActivitiUtils.createInSet(variableNames));
  query.append(")");
  return historyService.createNativeHistoricVariableInstanceQuery().sql(query.toString()).parameter("proc_inst_id", processInstanceId).list();
}
</code>

But when we invoke "HistoricVariableInstance#getValue()",

<code>
private void mapVarList(List<HistoricVariableInstance> historicVariableInstances, Map<String, UserLoopResponses> varMap) {
  if (historicVariableInstances == null || historicVariableInstances.isEmpty()) {
   return;
  }
  for (HistoricVariableInstance hiVariable : historicVariableInstances) {
   Object value = hiVariable.getValue();//This line throws npe

   if (value == null || !(value instanceof UserLoopResponses)) {
    continue;
   }
   varMap.put(hiVariable.getVariableName(), (UserLoopResponses) value);
  }
}
</code>

we get :

<code>
java.lang.NullPointerException
at org.activiti.engine.impl.persistence.entity.ByteArrayRef.ensureInitialized(ByteArrayRef.java:94)
at org.activiti.engine.impl.persistence.entity.ByteArrayRef.getBytes(ByteArrayRef.java:45)
at org.activiti.engine.impl.persistence.entity.HistoricVariableInstanceEntity.getBytes(HistoricVariableInstanceEntity.java:119)
at org.activiti.engine.impl.variable.ByteArrayType.getValue(ByteArrayType.java:32)
at org.activiti.engine.impl.variable.SerializableType.getValue(SerializableType.java:51)
</code>
Historic value is serializable type. Now my question, is this is the same bug (i tried on version 5.14 but still that same) or i can't get serializable value by nativequery
(i'm beginer at activiti so i may have probably doing something silly )?

[trademak]

The query that you are performing can also be done via the standard Activiti API.
It was a bug in 5.13, but it should be working in 5.14. Could you create a JIRA issue with a unit test showing the issue?

Best regards,