json4s/json4s

A single AST to be used by other scala json libraries

Jonas Natten

@jnatten

Anyone has any idea why my deserialization breaks when going from json4s 3.5.5 to 3.6.x?
I just use read[LearningPath](jsonString) in my constructor to deserialize and the LearningPath type is defined like this: http://scalikejdbc.org/documentation/one-to-x.html
stacktrace -> https://hastebin.com/naxadomano.scala

Jonas Natten

@jnatten

Correction: It breaks from 3.6.0 -> 3.6.1 ^

Colin Williams

@KE7CFN_twitter

Hi I'm looking at what should be a simple example parsed Json. I'd like to navigate the AST to obtain a subvalue but am not following how to do that after looking at the LINQ style and XPath examples. Can someone elucidate me. E.G.

My JValue looks like

org.json4s.JValue = JObject(List((@context,JArray(List(JString(https://raw.githx,JString(https://api.weather.gov/ontology#)), (geo,JString(http://www.opengis.net/ontapi.weather.gov/ontology#))))))), (type,JString(Feature)), (geometry,JObject(List((typ, (coordinates,JArray(List(JDouble(-123.0102602), JDouble(48.5993352)))))), JObject(Li0288715), JDouble(48.6073768))), JArray(List(JDouble(-123.0224183), JDouble(48.5870264...

Then for example how can I get a flat easy to read list of reference "keys" to traverse maybe 1st level of the JObject ?

Colin Williams

@KE7CFN_twitter

I look at .values and it looks like

Map(@context -> List(https://raw.githubusercontent.com/geojson/geojson-ld/master/contexts/geojson-base.jsonld, Map(wx -> https://api.weather.gov/ontology#, geo -> http://www.opengis.net/ont/geosparql#, unit -> http://codes.wmo.int/common/unit/, @vocab -> https://api.weather.gov/ontology#)), type -> Feature, geometry -> Map(type -> GeometryCollection, geometries -> List(Map(type -> Point, coordinates -> List(-123.0102602, 48.5993352)), Map(type -> Polygon, coordinates -> List(List(List(-123.0288715, 48.6073768), List(-123.0224183, 48.5870264), List(-122.9916522, 48.5912913), List(-122.9980987, 48.6116418), List(-123.0288715, 48.6073768)))))), properties -> HashMap(periods -> List(HashMap(number -> 1, shortForecast -> Mostly Cloudy then Chance Light Rain, startTime ...

Colin Williams

@KE7CFN_twitter

Well I've exposed my ignorance. I will fiddle with it more and see if I can get somewhere...

Colin Williams

@KE7CFN_twitter

Looks like I can extract the xpath elements but still I'm curious why the .values "Map" doesn't provide Map "methods"

scala> parsed.values.
!=   +    ==             ensuring   formatted   hashCode       toString   
##   ->   asInstanceOf   equals     getClass    isInstanceOf   →

Colin Williams

@KE7CFN_twitter

scala> parsed.values.getClass
res117: Class[_ <: parsed.Values] = class scala.collection.immutable.Map$Map4

Anirudh Vyas

@AnirudhVyas

Hi there - how do I convert a case class to JObject directly without handcoding jObject - So far I can only see parse(write(caseClassInstance).snakizeKeys.asInstanceOf[JObject] ... but that is a lot of work to get case class

Anirudh Vyas

@AnirudhVyas

by a lot of work I meant lot of I/O

Andriy Plokhotnyuk

@plokhotnyuk

@AnirudhVyas as w/a you can try jsoniter-scala. It derives a safe and efficient JSON codec for a whole nested data structure by a one-liner macro call like here.

Andy Czerwonka

@andyczerwonka

wondering if there is an established pattern for parsing an array of dynamic objects, e.g. List[Either[ThisType, ThatTYpe]]

{
  "stuff": [
    {
      "a": null,
      "b": "wombat",
      "c": [],
      "d": 7,
      "uids": {
        "id": "0cd1a7f8-cee0-4f54-9c6b-534c123f2ec6"
      }
    },
    {
      "file_links": [],
      "name": "Abstract Butter",
      "notes": "Shortening for making rich, buttery baked goods",
      "process": {
        "id": "b8f748cf-c313-4f2c-8e38-84d7701f9609",
        "scope": "id",
        "type": "link_by_uid"
      }
    }
  ]
}

Anirudh Vyas

@AnirudhVyas

by a lot of work I meant lot of I/O

I am answering my question - to do what I needed (transform a product type to JObject directly -> http://json4s.org/ use decompose)

Markus

@mnotti

Hi, wondering if there's an idiomatic/easy way to write a JObject to a file?

Anirudh Vyas

@AnirudhVyas

Unsure about file - but I have used jackson.Serialization.write before to transform to a string and then perhaps to a file, but if someone else knows of a cleaner way all ears 👂

Greg Zoller

@gzoller

G'day... is there a json4s build against dotty?

Sankarshan Mudkavi

@Sankarshan-Mudkavi

Hey guys, does json4s support parsing and extraction in an akka stream? It seems to be hanging on the first object every time. I'm using JSONframing to stream the json objects from a filestream

Qubiq1337

@Qubiq1337

Hey guys, how to pop/remove value from json?

Anirudh Vyas

@AnirudhVyas

 val originalRequestWithoutRequestId = wc.originalRequest.removeField {
      case ("blah_field_name", _) => true
      case ("another_blah_field_name", _) => true
      case _                 => false
    }

@Qubiq1337 ^^

Qubiq1337

@Qubiq1337

Anirudh Vyas

@AnirudhVyas

@gzoller dotty is not stable yet ... unsure why there would until they finalize everything?

Pavel Zorin

@pazone

Hi folks. How do I filter off objects from a json array?
For example:

  {
    "name": "John"
  },
  {
    "name": "Joseph"
  },
  {
    "name": "Peter"
  }
]

I'd like to filter off objects with names which are not starting with Jo:

  {
    "name": "John"
  },
  {
    "name": "Joseph"
  }
]

The result might be a String or JValue with json array inside.
Thanks.

Anirudh Vyas

@AnirudhVyas

JArray(List.empty).map {
      case JObject(values) => JObject(values.filter { case (fName, _) => fName.startsWith("Jo") })
    }

would something like this work?

Pavel Zorin

@pazone

Wow! Thanks. I'll try it

Jack Koenig

@jackkoenig

Is there a way to not error on

Exception in thread "main" org.json4s.package$MappingException: Do not know how to serialize key of type class my.custom.Type. Consider implementing a CustomKeySerializer.

, like a low-priority custom serializer that turns the error into a String in the emitted JSON or something?

Rohan Sircar

@rohan-sircar

Messed up the formatting. Reposting with correct formatting -

class MyJInstantSerializer
    extends CustomSerializer[Instant](format =>
      (
        {
          // case JInt(d) => Instant.ofEpochMilli(d.toLong)
          case JString(d) => Instant.parse(d)
          case JNull      => null
        }, {
          // case d: Instant => JInt(d.toEpochMilli)
          case d: Instant => JString(d.toString())
        }
      )
    )

Thomas Järvstrand

@tjarvstrand

Hi! Is this room still active? I was wondering if there are any plans to release 3.7.0 soon?

Andy Czerwonka

@andyczerwonka

I noticed that TypeHints trait method classFor changed it's signature. Can someone point me to the new API docs or release notes for this breaking change?

Thomas Järvstrand

@tjarvstrand

@andyczerwonka I'm not sure if there are any. If it helps, here's the PR: https://github.com/json4s/json4s/pull/732/files

Basically the type hint now needs to know a common parent class to be able disambiguate between hints with the same name

Saad Khawaja

@SaadKhawaja

json4s-core_3.0.0-RC2 is missing in maven central, when will it be available? Thanks.

Thomas Järvstrand

@tjarvstrand

@SaadKhawaja I'd open an issue on github. Unfortunately I don't think any of the maintainers watch this channel

Saad Khawaja

@SaadKhawaja

@tjarvstrand Thanks I did here json4s/json4s#784

ankusharya

@ankusharya

What is the coordinate for scala-native json4s library? Can anyone guide me? Thanks

Thomas Järvstrand

@tjarvstrand

@ankusharya Looks like it should be "org.json4s" % s"json4s-native_$scalaNativeVersion" % json4sVersion. You can find it here: https://search.maven.org/search?q=json4s-native

Noah Zucker

@noahlz

Hello! I see that 3.7.0 is in the works - is the Milestone release suitable for production use?

I saw a commit made referencing my issue json4s/json4s#771

Andriy Plokhotnyuk

@plokhotnyuk

@noahlz I would double think before using of latest json4s releases and milestones in case of accepting untrusted input through them.

Noah Zucker

@noahlz

Double think? You mean.. think twice until these are fixed?

DavidGoodenough

@DavidGoodenough

I have code that used to work in scala-2 but when I move to 3.0.0rc3 it complains that // is not a member of JValue. Any ideas?

Nadav Samet

@thesamet

Is json4s-jackson for Scala 3 in scope for 3.7.0 - I see that it's currently disabled in the build.

Nadav Samet

@thesamet

@xuwei-k ^ is it planned to have json4s-jackson available for Scala 3, or is it recommended to use a different implementatin?

xuansontrinh

@xuansontrinh

hello, is there any way that I can have serialized JSON string that also has the typehints of primitive types with json4s-jackson? At the moment they are skipped completely.

Tim Pigden

@TimPigden

Hello, I'm trying to use scala 3.0.1
Something that worked before no longer compiles, with this error

value \ is not a member of org.json4s.JsonAST.JValue, but could be made available as an extension method.

One of the following imports might fix the problem:

import org.json4s.MonadicJValue.jvalueToMonadic

Am I expecting scala3 to work properly? It's not clear

Where communities thrive

People

Repo info

Activity