Playing With Play2 SCALA JSON API Stand-alone

Now play-json stand-alone is officially a stand-alone module in Play2.2. So you don’t have to use the dependency given in this article anymore but use Typesafe one like com.typesafe.play:play-json:2.2

In a very recent Pull Request, `play-json has been made a stand-alone module in Play2.2-SNAPSHOT master as play-iteratees.

It means:

• You can take Play2 Scala Json API as a stand-alone library and keep using Json philosophy promoted by Play Framework anywhere.
• play-json module is stand-alone in terms of dependencies but is a part & parcel of Play2.2 so it will evolve and follow Play2.x releases (and following versions) always ensuring full compatibility with play ecosystem.
• play-json module has 3 ultra lightweight dependencies:
  • play-functional
  • play-datacommons
  • play-iteratees

These are pure Scala generic pieces of code from Play framework so no Netty or whatever dependencies in it.
You can then import play-json in your project without any fear of bringing unwanted deps.

play-json will be released with future Play2.2 certainly so meanwhile, I provide:

• a build published in my Maven Github repository
• a sample project called play-json-alone

Even if the version is 2.2-SNAPSHOT, be aware that this is the same code as the one released in Play 2.1.0. This API has reached a good stability level. Enhancements and bug corrections will be brought to it but it’s production-ready right now.

Adding play-json 2.2-SNAPSHOT in your dependencies

In your Build.scala, add:

1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22

import sbt._
import Keys._

object ApplicationBuild extends Build {

  val mandubianRepo = Seq(
    "Mandubian repository snapshots" at "https://github.com/mandubian/mandubian-mvn/raw/master/snapshots/",
    "Mandubian repository releases" at "https://github.com/mandubian/mandubian-mvn/raw/master/releases/"
  )

  lazy val playJsonAlone = Project(
    BuildSettings.buildName, file("."),
    settings = BuildSettings.buildSettings ++ Seq(
      resolvers ++= mandubianRepo,
      libraryDependencies ++= Seq(
        "play"        %% "play-json" % "2.2-SNAPSHOT",
        "org.specs2"  %% "specs2" % "1.13" % "test",
        "junit"        % "junit" % "4.8" % "test"
      )
    )
  )
}

Using play-json 2.2-SNAPSHOT in your code:

Just import the following and get everything from Play2.1 Json API:

1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27

import play.api.libs.json._
import play.api.libs.functional._

case class EucalyptusTree(col:Int, row: Int)

object EucalyptusTree{
  implicit val fmt = Json.format[EucalyptusTree]
}

case class Koala(name: String, home: EucalyptusTree)

object Koala{
  implicit val fmt = Json.format[Koala]
}

val kaylee = Koala("kaylee", EucalyptusTree(10, 23))

println(Json.prettyPrint(Json.toJson(kaylee)))

Json.fromJson[Koala](
  Json.obj(
    "name" -> "kaylee",
    "home" -> Json.obj(
      "col" -> 10,
      "row" -> 23
    )
)

Using play-json, you can get some bits of Play Framework pure Web philosophy.
Naturally, to unleash its full power, don’t hesitate to dive into Play Framework and discover 100% full Web Reactive Stack ;)

Thanks a lot to Play Framework team for promoting play-json as stand-alone module!
Lots of interesting features incoming soon ;)

Have fun!