JsonSerializer add method to discard value to print

[kanowins]

It could be very handy to have a method to discard some fields by value.

In my use case, I use for integers the value Integer.MIN_VALUE to discard the field. I can achieve this with annotations, but in my project I want this feature for all integers and I have a lot, I can forget the annotations for an integer... So this method could centralize all this stuff and will be very safe.

Just modify JsonSerializer to add this method
public boolean discard(SerializerProvider provider, T value) {
return false;
}

And call it on BeanPropertyWriter, method serializeFields before starting to serialize.

[JooHyukKim]

So what you are suggesting is global configuration that works like...

if (enableDiscardOnValue && value.equals(configuredValue)) {
    // do not serialize
}

... this?

[kanowins]

A global configuration might be even more effective than my approach. I assume you mean that enableDiscardOnValue and configuredValue can be set for any Java type.

[cowtowncoder]

There is a technical reason why adding such method in JsonSerializer might not be practical to do: as things are, serializers cannot refuse to write a JSON Value -- skipping must be handled by "parent" serializer. So there's a lot that needs to be done when delegating, to be able to skip/discard/ignore value write.

But... Maybe consider existing @JsonInclude with custom filter?

https://cowtowncoder.medium.com/jackson-tips-filtering-with-jsoninclude-27f08979514c

that works today.

[JooHyukKim]

@kanowins This will do?

[kanowins]

Yes, I'm currently using the @JsonInclude directive. My suggestion comes from having to add this directive to every integer field in my project, which I don't think is ideal. The global configuration you mentioned earlier sounds like a good solution, if it's possible.

I see this feature as a way to change how Jackson handles some types by default. I think JsonSerializer is supposed to do this job, but it isn't working for me right now.

Thank you for your support!