Various code snippets for working with the Play Framework

json-samples.scala

import play.api.libs.json._
import play.api.libs.json.Reads._
// construct a json
val user = Json.obj("email" -> "[email protected]", "firstName" -> "Foo", "lastName" -> "Bar")


// > user: play.api.libs.json.JsObject = {"email":"[email protected]","firstName":"Foo","lastName":"Bar"}
println(s"user -> $user")
// > user -> {"email":"[email protected]","firstName":"Foo","lastName":"Bar"}

// get just the email from the JsValue
val email = (user \ "email").asOpt[String].getOrElse("No email!")
// > email: String = [email protected]
println(s"email -> $email")
// > email -> [email protected]

// create a case class to serialize to
case class User(email : String, firstName : String, lastName :String, middleName : Option[String])
// define a formats using JSON 'inception'
implicit val userFormats = Json.format[User]


// ask for an instance of the case class
val userFromJson = Json.fromJson(user)


// > userFromJson: play.api.libs.json.JsResult[User] = JsSuccess(User([email protected],Foo,Bar,None),)
println(s"user class ->  $userFromJson")
// > user class ->  JsSuccess(User([email protected],Foo,Bar,None),)


// add the middleName - via concatenation
val userWithMiddleName = user ++ Json.obj("middleName" -> "Blazz")

println(s"userWithMiddleName -> $userWithMiddleName")


// > userWithMiddleName -> {"email":"[email protected]","firstName":"Foo","lastName":"Bar", "middleName":"Blazz"}
// update the middleName - via transform

def updateMiddleName(name : String) = {
  (__ \ 'middleName).json.update(
    of[JsString].map { case JsString(_) => JsString(name) }
  )
}

val userUpdatedMiddleName = userWithMiddleName.transform(updateMiddleName("Blee"))


// > userUpdatedMiddleName: play.api.libs.json.JsResult[play.api.libs.json.JsObject]
// = JsSuccess({"email":"[email protected]","firstName":"Foo","lastName":"Bar","middlename":"Blee"},/middleName)

println(s"updated middleName ${userUpdatedMiddleName.get}")
// > updated middleName {"email":"[email protected]","firstName":"Foo","lastName":"Bar","middleName":"Blee"}

ws-sample.scala

import play.api.libs.ws.WS
import scala.concurrent.ExecutionContext.Implicits.global
import scala.util.{Failure, Try, Success}

val futureResults = WS.url("http://localhost:9000/ping").withHeaders("Accept" -> "application/json").get().map {
  results =>
    Try(
      if (results.status == 200)
        results.json
      else
        throw new Exception(s"Error while requesting ping!  Status: ${results.status} Body: ${results.body}")
    )
}

// > futureResults: scala.concurrent.Future[scala.util.Try[play.api.libs.json.JsValue]]

futureResults.map {
  case Success(json) => println(s"received JSON: $json")
  case Failure(e) => println(s"Failure due to: ${e.getMessage}")
}

// received JSON: {"results":"ok"}