Java common variable across the objects for a request

I using Kafka to get a message and update its corresponding data if already present in the DB. There lot of complex objects involved for the synchronization.

I wanted to print at the end of synchronization, all the objects that has got updated. Flow starts like below,

public class Consumer {
  @KafkaListener(topics = "${kafka.topics.test}")
  public void synchroData(FinTechData finTechData) {
    finService.update(finTechData);
  }
}

public class FinServiceImpl {
   public void updateMetrics(FinTechData finTechData) {
     if (finTechData != null) {
       //update finTechData data ....
       revolverService.updateRevolver(finTechData.getRevolver());
     }
   } 
}

public class RevolverServiceImpl {
   public void updateRevolver(Revolver revolver) {
     if (revolver != null) {
       //update revolver data ....
       utilizationService.updateUtilization(revolver.getUtilization());
       exposureService.updateexposure(revolver.getExposure()); 
     } 
   } 
}

....

It goes on for 8 to 10 objects. At the end I wanted to know what are the objects that got updated.
Currently I have a class like below with List of String as property and everytime when any object gets updated,

public class Context {
List<String> objectsUpdated = new ArrayList<>();
}

I add a message to it. But I need to pass the object to all the methods down the line. Is there any efficient way of doing it ?

I looking for below,

FinTech Data updated
Revolver Data updated
Exposure Data updated
...

You can wrap your Context class with ThreadLocal, e.g. in your Consumer class add:

public static final ThreadLocal<Context> perThreadContext = new ThreadLocal();

Then in synchroData() add perThreadContext.set(new Context()); before calling finService.update(finTechData);
and use Consumer.perThreadContext.get(); in each one of the updaters when you want to add a new entry to the context.

The ThreadLocal wrapper will create a separate instance of Context for each consumer thread. This way you'll have the list of objects updated by this specific invocation of the method.

See: https://www.baeldung.com/java-threadlocal for additional read bout ThreadLocal.