在Scala中使用Spray将UUID写入JSON

Question

我在Scala和Spray的应用程序中返回JSON中的UUID有一些问题。当实体User(id: UUID, name: String)被解析为JSON时，我收到:

 {
     "id": {
         "mostSigBits": 1310448748437770800,
         "leastSigBits": -7019414172579620000
      },
      "name": "Sharekhan"
 }

我希望收到String format中的uuid。比如:

 {
     "id": "122fa631-92fd-11e2-9e96-0800200c9a63",
      "name": "Sharekhan"
 }

我定义了UUID格式，当我从JSON解析到User时执行Read，但Write不以相反的顺序使用(User -> Json)

 implicit object UuidJsonFormat extends RootJsonFormat[UUID] {
   def write(x: UUID) = JsString(x.toString) //Never execute this line
   def read(value: JsValue) = value match {
      case JsString(x) => UUID.fromString(x)
      case x           => deserializationError("Expected UUID as JsString, but got " + x)
   }
 }

是否有任何方法可以做到这一点?我应该将UUID转换为用户实体中的字符串吗?

任何帮助都将不胜感激，

谢谢。

Answer 1

确保Uuid的隐式格式在使用它的用户格式之前，它应该工作:

object UserJsonProtocol extends DefaultJsonProtocol {
 implicit object UuidJsonFormat extends RootJsonFormat[UUID] {
   def write(x: UUID) = JsString(x.toString) //Never execute this line
   def read(value: JsValue) = value match {
      case JsString(x) => UUID.fromString(x)
      case x           => deserializationError("Expected UUID as JsString, but got " + x)
   }
 }
 implicit val UserFormat = jsonFormat2(User)
}