writer saves Map<String, CustomType> as Map<Object, Object>

[Extern-Till-Gehrke]

Steps to reproduce

• camunda-bpm-data version: 1.2.8
• Camunda BPM version: 7.19.0 with spring boot camunda starter
• JDK version: 11
• Operating system: Windows
• Complete executable reproducer: organization repo
• Steps: (what exactly are you doing with the above reproducer?)
  I have following:
  public static final VariableFactory<Map<String, StorageFile>> DOCUMENTS = mapVariable(DOCUMENTS_KEY, String.class, StorageFile.class);
  via Spring boot rest endpoint following get executed:

public ResponseEntity<String> addFileToRequest(@RequestHeader("X-Tenant-ID") String gp, @PathVariable String reqId, @RequestBody StorageFile storageFile) {
       var pi = runtimeService.createProcessInstanceQuery().processInstanceBusinessKey(reqId).singleResult();
       securityService.checkBusinessPartner(pi, gp);
       log.debug("Found " + pi.getId() + " ProcessInstance for BusinessKey " + reqId);

       VariableReader reader = CamundaBpmData.reader(runtimeService, pi.getId());
       var linkedfiles = reader.getOrDefault(ProcessVariables.DOCUMENTS, new HashMap<>());
       var status = reader.get(ProcessVariables.STATUS);

       ...

       linkedfiles.put(storageFile.getUuid(), storageFile);
       VariableWriter<?> writer = CamundaBpmData.writer(runtimeService, pi.getId());
       writer.set(ProcessVariables.DOCUMENTS, linkedfiles);

}

and the failing reader running as Spring @org.springframework.scheduling.annotation.Scheduled:

List<ProcessInstance> processInstances = runtimeService.createProcessInstanceQuery().processDefinitionKey("document-request").active().orderByProcessInstanceId().desc().list();
            log.debug("found {} active process-request instances", processInstances.size());
            for (ProcessInstance pi : processInstances) {

                VariableReader variableReader = reader(runtimeService, pi.getId());
...
                var documents = variableReader.getOrDefault(ProcessVariables.DOCUMENTS, new HashMap<>());

Expected behaviour

In Camunda should the value of documents from Map<String, StorageFile> type

Actual behaviour

In Camunda Cockpit the Type (Value) of documents is Map<Object, Object> with the saved StorageFIle data and the reader() will fail with
Error reading documents: Wrong map type detected, expected Map<java.lang.String,my.package.StorageFile, but was not found in {78c33e4d-351d-449e-9932-d752d964f2ab={filename=dummy.pdf, size=1, owner=Name, uuid=78c33e4d-351d-449e-9932-d752d964f2ab, status=UPLOAD}}

(In case of exceptions provide full stack trace)

io.holunda.camunda.bpm.data.adapter.WrongVariableTypeException: Error reading documents: Wrong map type detected, expected Map<java.lang.String,my.package.StorageFile, but was not found in {78c33e4d-351d-449e-9932-d752d964f2ab={filename=dummy.pdf, size=1, owner=Name, uuid=78c33e4d-351d-449e-9932-d752d964f2ab, status=UPLOAD}} at io.holunda.camunda.bpm.data.adapter.map.AbstractMapReadWriteAdapter.getOrNull(AbstractMapReadWriteAdapter.java:63) ~[camunda-bpm-data-1.2.8.jar:na] at io.holunda.camunda.bpm.data.adapter.map.MapReadWriteAdapterRuntimeService.getOptional(MapReadWriteAdapterRuntimeService.java:37) ~[camunda-bpm-data-1.2.8.jar:na] at io.holunda.camunda.bpm.data.reader.RuntimeServiceVariableReader.getOptional(RuntimeServiceVariableReader.java:32) ~[camunda-bpm-data-1.2.8.jar:na] at io.holunda.camunda.bpm.data.reader.VariableReader.getOrDefault(VariableReader.java:72) ~[camunda-bpm-data-1.2.8.jar:na] at my.package.DocumentsStatusUpdateService.updateDocumentsStatus(DocumentsStatusUpdateService.java:56) ~[classes/:na] at jdk.internal.reflect.GeneratedMethodAccessor117.invoke(Unknown Source) ~[na:na] at java.base/jdk.internal.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43) ~[na:na] at java.base/java.lang.reflect.Method.invoke(Method.java:566) ~[na:na] at org.springframework.scheduling.support.ScheduledMethodRunnable.run(ScheduledMethodRunnable.java:84) ~[spring-context-5.3.27.jar:5.3.27] at org.springframework.scheduling.support.DelegatingErrorHandlingRunnable.run(DelegatingErrorHandlingRunnable.java:54) ~[spring-context-5.3.27.jar:5.3.27] at java.base/java.util.concurrent.Executors$RunnableAdapter.call(Executors.java:515) ~[na:na] at java.base/java.util.concurrent.FutureTask.runAndReset(FutureTask.java:305) ~[na:na] at java.base/java.util.concurrent.ScheduledThreadPoolExecutor$ScheduledFutureTask.run(ScheduledThreadPoolExecutor.java:305) ~[na:na] at java.base/java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1128) ~[na:na] at java.base/java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:628) ~[na:na] at java.base/java.lang.Thread.run(Thread.java:834) ~[na:na]

[zambrovski]

Currently can't reproduce it using the example. Will still let it opened.