Styjun

I am trying to run a play application where I have used guice for dependency injection.

My controller is as follows

import scala.concurrent.ExecutionContext
import javax.inject.Inject
import play.api.libs.json.Json
import play.api.mvc._

class MyControllers @Inject()(
 service: MyService,
 cc: MessagesControllerComponents)(implicit ec: ExecutionContext)
 extends MessagesAbstractController(cc) {

 def getAll(id: Int): Action[AnyContent] = Action.async implicit request =>
 // code to fetch from service and return result
 

Similarly in my service I have dependency injected the DAO as

class MyService @Inject()(dao: MyDAO)(implicit ec: ExecutionContext) 

// call to DB

My build.sbt file looks something like this

name := """service-application"""

version := "2.6.x"

scalaVersion := "2.12.7"

crossScalaVersions := Seq("2.11.12", "2.12.4")

libraryDependencies ++= Seq(
 guice,
 "com.typesafe.play" %% "play-slick" % "3.0.3",
 "com.typesafe.play" %% "play-slick-evolutions" % "3.0.3",
 "org.mockito" % "mockito-all" % "1.10.19" % Test,
 "com.h2database" % "h2" % "1.4.197",
 "org.scalactic" %% "scalactic" % "3.0.5",
 "org.scalatest" %% "scalatest" % "3.0.5" % "test",
 "org.scalatestplus.play" %% "scalatestplus-play" % "3.1.2" % Test,
 "net.codingwell" %% "scala-guice" % "4.1.0",
 "com.typesafe.slick" %% "slick-codegen" % "3.2.1",
 "com.typesafe.slick" %% "slick-testkit" % "3.2.3" % Test,
 specs2 % Test
)

addSbtPlugin("com.geirsson" % "sbt-scalafmt" % "1.5.1")

routesGenerator := InjectedRoutesGenerator

However, now when I am trying to run the play application via the sbt shell using command

run

I get the error as

[IJ]sbt:service-application> run
[error] java.lang.RuntimeException: No main class detected.
[error] at scala.sys.package$.error(package.scala:27)
[error] (Compile / bgRun) No main class detected.
[error] Total time: 1 s

Could you please let me know what I am missing here ? Is it some kind of configuration that I am missing in the conf file ?

Thanks in advance !!!