Scala 找不到Seq[models.Comment]类型的Json格式化程序。请尝试实现此类型的隐式格式

您好scala和playFramework大师

我不明白为什么隐式

Json.format[Comment]

在我的代码中不起作用。从文档描述来看，它应该是

格式[注释]

，但看起来不是这样

这是我的两个案例类及其同伴的代码

case class ServiceTask(id: Option[String],
                       name: String,
                       description: String,
                       requiredInfo: String,
                       status: String,
                       approved: Boolean,
                       comments: Option[Seq[Comment]])
object ServiceTask {

  implicit val serviceTaskFormat: Format[ServiceTask] = (
    (JsPath \ "id").formatNullable[String] and
    (JsPath \ "name").format[String] and
    (JsPath \ "description").format[String] and
    (JsPath \ "requiredInfo").format[String] and
    (JsPath \ "status").format[String] and
    (JsPath \ "approved").format[Boolean] and
    (JsPath \ "comments").formatNullable[Seq[Comment]]
  )(ServiceTask.apply _, unlift(ServiceTask.unapply))

}

及

---

似乎您没有在

对象服务任务格式

中导入

注释格式

。试试这个：

object ServiceTask {
  import Comment._

  implicit val serviceTaskFormat: Format[ServiceTask] = (
    (JsPath \ "id").formatNullable[String] and
    (JsPath \ "name").format[String] and
    (JsPath \ "description").format[String] and
    (JsPath \ "requiredInfo").format[String] and
    (JsPath \ "status").format[String] and
    (JsPath \ "approved").format[Boolean] and
    (JsPath \ "comments").formatNullable[Seq[Comment]]
  )(ServiceTask.apply _, unlift(ServiceTask.unapply))
}

---

正确的。在

ServiceTask

my

Comment

中，隐式格式以前是不可见的。谢谢提醒您，当您的主要案例类中有多个内部案例类时，需要先定义内部案例类的json

格式

，为主要案例类定义json

格式

；（JsPath\“id”）.formatNullable[Long]

object ServiceTask {
  import Comment._

  implicit val serviceTaskFormat: Format[ServiceTask] = (
    (JsPath \ "id").formatNullable[String] and
    (JsPath \ "name").format[String] and
    (JsPath \ "description").format[String] and
    (JsPath \ "requiredInfo").format[String] and
    (JsPath \ "status").format[String] and
    (JsPath \ "approved").format[Boolean] and
    (JsPath \ "comments").formatNullable[Seq[Comment]]
  )(ServiceTask.apply _, unlift(ServiceTask.unapply))
}