gistfile1.scala

// a simple POJO
case class Address(street: String, city: String, zip: String)
object AddressProtocol extends DefaultProtocol {
    implicit val AddressFormat: Format[Address] = 
      asProduct3("street", "city", "zip")(Address)(Address.unapply(_).get)
}

// aggregate containing list
case class Contact(name: String, addresses: List[Address])
import AddressProtocol._
object ContactProtocol extends DefaultProtocol {
    implicit val ContactFormat: Format[Contact] = 
      asProduct2("name", "addresses")(Contact)(Contact.unapply(_).get)
}

// test case
import ContactProtocol._

// instantiate
val contact = Contact("Debasish Ghosh", 
        List(Address("monroe st", "denver", "80231"), Address("pine drive", "santa clara", "95054")))
// serialize & de-serialize
fromjson[Contact](tojson(contact)) should equal(contact)