覆盖播放的值 JSON 组合器写入

Question

假设我json这样写

  implicit val userWrites: Writes[User] = (
    (__ \ "name").write[String] ~
      (__ \ "email").write[String] ~
      (__ \ "encryptedPassword").write[String] ~
      (__ \ "id").writeNullable[Long]
    )(unlift(User.unapply))

如果我不想打印出密码，而只是打印一个字符串 "hidden"，我该如何使用组合器实现这一点？

我正在寻找与此类似的解决方案

  implicit val userWrites: Writes[User] = (
    (__ \ "name").write[String] ~
      (__ \ "email").write[String] ~
      (__ \ "encryptedPassword").write[String](Writes.pure("hidden")) ~
      (__ \ "id").writeNullable[Long]
    )(unlift(User.unapply))

Answer 1

你可以这样做：

implicit val userWrites = new Writes[User] {
  override def writes(user: User): JsValue = Json.obj(
    "name" -> user.name,
    "email" -> user.email,
    "encryptedPassword" -> "hidden",
    "id" -> user.id
  )
}

Answer 2

这应该有效：

implicit val userWrites: Writes[User] = (
    (__ \ "name").write[String] ~
      (__ \ "email").write[String] ~
      (__ \ "encryptedPassword").write[String](Writes((_: String) => JsString("hidden"))) ~
      (__ \ "id").writeNullable[Long]
    )(unlift(User.unapply))

覆盖播放的值 JSON 组合器写入

Overwrite value of Play JSON Combinator Writes

json

playframework

playframework-2.4