Feature: JacksonCollection.toJsonNode(ObjectMapper) for Java Streams and FP

[rikkarth]

Hi guys,

I'd like to contribute to Jackson. I have this personal implementation of mine that I use for my projects, and I believe it would be a good addition to Jackson.

This implementation is compatible with Java 8+ and is used in Java Streams.

In essence, it simplifies collection of JsonNode.

If you're like me and use a lot of FP and Streams in Java this is really cool.

Something like:

final JsonNode arrayNode = mylist.stream()
    .map(item -> getJsonNode(item))
    .collect(JacksonCollections.toJsonNode(objectMapper))

Real world enterprise application example:

    private JsonNode getShapes(final Node content) {
        final NodeList shapes = this.xmlHelper.getNodeListFromXpath("Shape", content);
        return IntStream.range(0, shapes.getLength())
            .mapToObj(shapes::item)
            .map(this::getShape)
            .collect(jsonNodeCollector(this.objectMapper));
    }

The signatures don't have to be exactly this, and I'm totally open for suggestions.

I would like to understand if it would be worth it for me to submit a PR with this implementation, or would this not be appreciated at all?

Additionally, I would like to know which repo would be best to deliver this PR to. Core?

[cowtowncoder]

I am not 100% sure I quite understand the specific idea/suggestion, but I think that:

1. Adding more support within JsonNode to help with Java 8 streams (new accessors) would be fine
2. I am not a big fan of adding helper classes (like JsonNodeUtil or JacksonCollection), ideally extensions would start from existing main API types
3. This would almost certainly go in jackson-databind.

So: improving ergonomics, +1. Just need to know how, what and where to add pieces.

[rikkarth]

Hi @cowtowncoder

I will provide a proposal through a PR and maybe we can discuss it a bit more thoroughly there.

Thank you for your feedback, I really appreciate it.

[rikkarth]

For back reference:
FasterXML/jackson-databind#4691