What date/time class should I be mapping too?

Question

I am writing a case class that will map to a JSON result that I am getting from an external API response.

The datetime looks like: 2016-05-30T00:23:27.070Z

What type should I use to map to this datetime string?

I want to use playframework's json automapper so I can just do:

implicit val userReads = Json.reads[User]

case class User(createdAt: ?????)

Answer 1

There is already predefined Format for dates DefaultLocalDateTimeReads:

import java.time.LocalDateTime

val json = Json.parse("""{"date": "2016-05-30T00:23:27.070Z"}""")
(json \ "date").as[LocalDateTime]

In case you need some other dateTime library/format, you could write custom reader like this one:

import org.joda.time.DateTime
import play.api.libs.json.{JsError, _}


implicit object DateTimeReads extends Reads[DateTime] {
  val Format = org.joda.time.format.DateTimeFormat
    .forPattern("yyyy-MM-dd'T'HH:mm:ss.SSS'Z'")

  def reads(json: JsValue) = json match {
    case JsString(x) => JsSuccess(Format.parseDateTime(x))
    case _           => JsError(s"Can't read $json as DateTime")
  }
}

(json \ "date").as[DateTime]
res0: org.joda.time.DateTime = 2016-05-30T00:23:27.070+03:00

Answer 2

import java.time.LocalDateTime

case class User(createdAt: LocalDateTime)

implicit val userReads = Json.reads[User]