创建read for Play 2.1时出现类型不匹配错误

Question

我已经玩了几个小时了。我一直在尝试不同的方法来创建一个read，但我完全被难住了。

我在Play 2.1.0和Scala 2.10.1上

错误:

type mismatch; found : models.Registration.type required: play.api.libs.json.Reads[?]

代码:

package models
import play.api.libs.json._
import play.api.libs.functional.syntax._
case class Registration(
        user: (String,String,String,String,String,String)
)
object RegistrationHelper {
    implicit val regReads: Reads[Registration] = (
      (__  "user").read(
        (__  "id").read[String] and
        (__  "username").read[String] and
        (__  "first_name").read[String] and
        (__  "last_name").read[String] and
        (__  "email_address").read[String] and
        (__  "user_avatar").read[String]
        tupled
      )
    )(Registration) //!!ERROR ON THIS LINE
}

JSON:

{
  user: {
    id: "35fc8ba5-56c3-4ebe-9a21-489a1a207d2e",
    username: "flastname",
    first_name: "Firstname",
    last_name: "Lastname",
    email_address: "[e-mail]",
    user_avatar: "http://blog.ideeinc.com/wp-content/uploads/2010/04/tineye-robot.jpg"
  }
}

Answer 1

应该可以:

implicit val regReads: Reads[Registration] = (__  "user").read(
    (__  "id").read[String] and
      (__  "username").read[String] and
      (__  "first_name").read[String] and
      (__  "last_name").read[String] and
      (__  "email_address").read[String] and
      (__  "user_avatar").read[String]
      tupled
  ) map Registration.apply _