Event Registry - Kafka - Avro

Flowable Engine
#1

Hello.
We are currently implementing Flowable Event Registry with Kafka as a channel type. Currently we are using Avro in our system and we are searching a way to implement custom EventPayload Avro serializer/deserializer.

Can you give us some hint or guidance on how to achieve that?

#2

You can customize serializers/deserializers by defining the serializer/deserializer type in the channel definition file as “expression”. For instance a inbound channel definition file would look something like:

{
  "type": "kafka",
  "channelType": "inbound",
  "deserializerType": "expression",
  "deserializerDelegateExpression" : "${myCustomDeserializer}",
...
}

where ${myCustomDeserializer} is a Spring bean named myCustomDeserializer and is implemented like

public class MyCustomDeserializer implements InboundEventDeserializer<T> {
     @Override
     public T deserialize(String rawEvent) {
               ....
     }

T is the type the deserializer produces from parsing the rawEvent. The default deserializer in Flowable produces types of JsonNode. If the deserializer produces a type other than JsonNode, then you will need to implement InboundEventPayloadExtractor as well and install those in your channel definition file as:

"payloadExtractorDelegateExpression":"${myPayloadExtractor}"

1 Like
#3

Thank you for the information. We will certainly try it and see if it suits our needs.