Question

我有以下Reads对象：

implicit val branchRead: Reads[BranchApplyRequest] = (
      (JsPath \ "act").read[String] and
      (JsPath \ "st").read[String] and
      (JsPath \ "nts").read[String] and
      (JsPath \ "bk").read[Int]
    ) (BranchApplyRequest.apply _)

问题是，当其中一个字段不是来自浏览器时，我会收到异常并且程序失败。理想情况下，非现场字段可用但未定义。如何实现？

Answer 1

请改用readNullable。例如，如果act为Optional：

implicit val branchRead : Reads[BranchApplyRequest] = (
      (JsPath \ "act").readNullable[String] and
      (JsPath \ "st").read[String] and
      (JsPath \ "nts").read[String] and
      (JsPath \ "bk").read[Int]
    )(BranchApplyRequest.apply _)

当然，您的BranchApplyRequest将是这样的：

case class BranchApplyRequest(act: Option[String], ...)

播放Json时，如果未填充字段，则会抛出异常

1 个答案: