How to return JSONObject from Activity to Workflow

Community Support
1

I’m getting this exception

Caused by: io.temporal.common.converter.DataConverterException: com.fasterxml.jackson.databind.exc.UnrecognizedPropertyException: Unrecognized field "empty" (class org.json.JSONObject), not marked as ignorable (one known property: "map"])

I tried to use https://github.com/FasterXML/jackson-datatypes-misc but did not work. Is it because the sdk is using a mapper that I cannot modify to support JSONObject?

2

I switched to use JsonNode from fasterxml.jackson
I suggest change have Temporal’s jackson mapper support org.json. It’s probably a one line change. I feel over time org.json will be very popular
But of course once Temporal support Typescript I’m out of Java

3

I’m confused. Are you trying to return JSONObject instead of its serialized form from an activity? Have you considered returning byte array that contains the serialized JSON?

4

Yes. I was returning JSONObject directly from Activity. Jackson automatically tries to serialize it but failed. I then switched to return JsonNode instead

5

I see. I don’t think we can change the default from Jackson, as it can be a breaking change. The good news that DataConverter is fully pluggable and you can choose whatever serializer you prefer.

6

Could you provide more info on DataConverter
I found only 2 mentions in the doc https://docs.temporal.io/search?q=DataConverter

7

We are planning to fully rewrite the SDKs documentation. DataConverter will be also covered.