Scala converting Map[String, Long] into JSON or JSON string

Question

I have a this object:

case class UserStateSummaryByHourPayload (
 ownerid: String,
 userid: String,
 team: String,
 profile: String,
 day: String,
 hour: Int,
 sortdate: String,
 month: String,
 durationpayload: Map[String, Long],
 maxdurationpayload: Map[String, Long]
 )

I would like to turn the two Map attributes into JSON or a string (writing to mysql column) such as this

case class JunkTest (
 ownerid: String,
 userid: String,
 team: String,
 profile: String,
 day: String,
 hour: Int,
 sortdate: String,
 month: String,
 durationpayload: String,
 maxdurationpayload: String
 )

I tried to do something like this following some other peoples guides, but its not working:

import com.fasterxml.jackson.module.scala.DefaultScalaModule;
 import com.fasterxml.jackson.databind.ObjectMapper;
 @transient val mapper = new ObjectMapper();
 mapper.registerModule(DefaultScalaModule);
 var junktest = ussapayloads.map(a => new JunkTest(
 a.ownerid, 
 a.userid,
 a.team, 
 a.profile, 
 a.day, 
 a.hour, 
 a.sortdate, 
 a.month, 
 mapper.writeValueAsString(a.durationpayload),
 mapper.writeValueAsString(a.maxdurationpayload)
 ));

How to I take my Map[String, Long] and turn it into JSON or a JSON string?

Map("Online" -> 100,"Ready" -> 200)
{ "Online": 100, "Ready": 200 }

Answer 1

Here you go!

import spray.json._
import DefaultJsonProtocol._
object Demo1 extends App {
val keyValue = Map("Online" -> 100, "Ready" -> 200)
 
println(keyValue.toJson) //output {"Online":100,"Ready":200}
}

Answer 2

Using play-json it is really easy:

import play.api.libs.json.Json
Json.stringify(Json.toJsObject(Map("Online" -> 100, "Ready" -> 200)))

Code run can be found at Scastie;

BTW, the code you attached works completely fine. You can find it in Scastie.

In order to install play-json please add the following to your build.sbt:

resolvers += "play-json" at "https://mvnrepository.com/artifact/com.typesafe.play/play-json"
libraryDependencies += "com.typesafe.play" %% "play-json" % "2.9.1"

• phattyD: I get exceptions with my above code: Caused by: java.io.NotSerializableException: com.fasterxml.jackson.module.paranamer.shaded.CachingParanamer
• Tomer Shetah: @phattyD Are you sure? Do you have redundant imports? Can you reproduce this failure in Scastie?
• phattyD: Yes I am sure, it works in Scastie, but does not work in my lab environment. I am trying implementations for the play-json and spray json now. Just trying to find the statements for adding to my sbt build to import the packages
• Tomer Shetah: @phattyD, I added what you need in your build.sbt
• phattyD: Thanks Tomer! I ended up with errors: Caused by: java.lang.ClassNotFoundException: play.api.libs.json.Writes I have tried importing play.api.libs.json._ and that didn't help. I had the same issues with the spray.json above. Is there a jar I need to add to classpath?