Adjust the object before returning the JSON response in Apache Camel with Jackson

Question

I'm using Apache Camel to build a REST POST endpoint that takes and object and returns another object as JSON:

from("direct:toProcessor").
        routeId("routeId").
        log(">>> ${body}").
        process(myProcessor);

rest("/api").
        id("route1").
        consumes("application/json").
        post("/test").
        bindingMode(RestBindingMode.json).
        type(RqObj.class).
        outType(RsObj.class).
        to("direct:toProcessor");

the MyProcessor.java class makes all the logic to use the RqObj object and build the RsObj response.

That works and I see the JSON response, but there is a problem, the RsObj contains dates as XMLGregorianCalendar with a specific timezone (and I cannot edit the definition of RsObj.java, because it's coming from an external dependency), so even if I set a date field to 2021-05-12T10:00:00.000+0000 at the end the returned JSON shows something else: 2021-05-12T08:00:00.000+0000 (different hour).

So I would like either to edit that field somehow during the serialization / deserialization process, or just customizing Jackson so that it uses a specific date format.

For instance, I made some attempts to tell Camel to use a customized ObjectMapper (as following):

ObjectMapper myObjectMapper = new ObjectMapper().setDateFormat(new SimpleDateFormat("EEE, dd MMM yyyy HH:mm:ss z"));

and using it in one of the following ways:

JacksonDataFormat jacksonDataFormat = new JacksonDataFormat(myObjectMapper, null);
final DataFormatDefinition dataFormatDefinition = new JsonDataFormat();
dataFormatDefinition.setDataFormat(jacksonDataFormat);
final Map<String, DataFormatDefinition> map = new HashMap<>();
map.put("json", dataFormatDefinition);
getContext().
        setDataFormats(map);

or:

from("direct:toProcessor").
        routeId("routeId").
        log(">>> ${body}").
        process(myProcessor).
        marshal(new JacksonDataFormat(myObjectMapper, CheckResponse.class)).
        unmarshal(new JacksonDataFormat(myObjectMapper, CheckResponse.class))

but none of those changes the result.

So what would it be your solution here?

Is there a way to tell Camel to adjust the response before returning is as JSON or what's the right way to customize Jackson in order to let it do it?

Thanks

score 0 · Answer 1 · answered Mar 31 '21 at 10:22

Based on your input I could see, the external entity is doing some kind of processing.

If date timezone is your problem , probably ,try converting the date to UTC before setting it in the object.

But if you want to have objectMapper do a special work for you, then you can define a custom object mapper

Customizing JSON Serializer

Adjust the object before returning the JSON response in Apache Camel with Jackson

1 Answers1