HttpRequest#getBody returns JSON String under 3.0.x but returns JsonObject under 3.1.0

[cbeams]

Issue description

Attn: @yawkat as this deals with JsonObject, which it appears you authored in 3.1.

I have a code path in my application where I get the current thread-local Micronaut HttpRequest (from ServerRequestContext#currentRequest) and I then "readdress" and "forward" that request on to another server.

I do this by copying the (json) body from the Micronaut HttpRequest into a new java.net.http.HttpRequest and sending it to the destination URI. Here's the relevant code:

    public static void forward(io.micronaut.http.HttpRequest<?> originalRequest, String newAddress) {
        send(readdress(originalRequest, newAddress));
    }

    private static HttpRequest.Builder readdress(io.micronaut.http.HttpRequest<?> originalRequest, String newAddress) {
        var request = request(newAddress + originalRequest.getUri());
        var body = originalRequest.getBody(String.class).orElse("");
        return request.method(originalRequest.getMethodName(), HttpRequest.BodyPublishers.ofString(body));
    }

    public static HttpRequest.Builder request(String uri) {
        return request().uri(UriBuilder.of(uri).build());
    }

    private static HttpRequest.Builder request() {
        return HttpRequest.newBuilder().header("Content-Type", "application/json");
    }

Note: this is all a bit of a hack, but it appears to be the best I can do. I might have preferred to create a mutable copy of the Micronaut HttpRequest, update its URI and then send it off with a Micronaut HttpClient, but the thread-local HttpRequest does not support the .mutate() call. That left me needing to create an all-new request.

In any case, under 3.0.3, the call above to originalRequest.getBody(String.class) returned with the JSON body of the original request, such that I could simply copy it over to the new request and send it.

On upgrading from 3.0.3 to 3.1.0-SNAPSHOT, however, this same call now returns io.micronaut.json.tree.JsonObject, which cannot as easily be passed on to the new request. How can I best get from this JsonObject back to a stringified JSON representation? Thanks.

[yawkat]

Thanks for catching this. #6296 is the fix.

Unfortunately, the new JsonNode class can't have a json toString, because that would need a dependency on jackson-core. You can implement the toString yourself using JsonNodeTreeCodec, or after the fix go through ConversionService or JsonMapper. And of course getBody will now work as it did before.

[cbeams]

Excellent, thanks! I'll try it out once #6296 is merged.

[cbeams]

I've tried out the fix in #6296 and it works as expected now. I'm able to run on the latest 3.1.0-SNAPSHOT with no issues. Thanks!