Convert any Scala object to JSON

Given that there is only a limited number of types you want to serialize to JSON, this should work:

object MyWriter {
  implicit val anyValWriter = Writes[Any] (a => a match {
    case v:String => Json.toJson(v)
    case v:Int => Json.toJson(v)
    case v:Any => Json.toJson(v.toString)
    // or, if you don't care about the value
    case _ => throw new RuntimeException("unserializeable type") 
  })
}

You can use it by then by importing the implicit value at the point where you want to serialize your Any:

import MyWriter.anyValWriter
val a: Any = "Foo"
Json.toJson(a)

Using json4s, you can import the package:

import org.json4s.DefaultFormats
import org.json4s.native.Serialization.write

Then create an implicit variable inside your trait:

implicit val formats: DefaultFormats = DefaultFormats

And finally, in your method, use it:

write(myObject)