2017-08-24 39 views
1

獲得對象的名單我想使用akka-http-spray-json 10.0.9spray-json。如何從JSON

我的模型:

case class Person(id: Long, name: String, age: Int) 

我得到JSON字符串jsonStr與人的名單,並嘗試分析它:

implicit val personFormat: RootJsonFormat[Person] = jsonFormat3(Person) 

val json = jsonStr.parseJson 
val persons = json.convertTo[Seq[Person]] 

錯誤:

Object expected in field 'id'


可能是我需要創建implicit object extends RootJsonFormat[List[Person]]並覆蓋readwrite方法。

implicit object personsListFormat extends RootJsonFormat[List[Person]] { 
    override def write(persons: List[Person]) = ??? 

    override def read(json: JsValue) = { 
     // Maybe something like 
     // json.map(_.convertTo[Person]) 
     // But there is no map or similar method :(
    } 
} 

P.S.對不起,我的英語不是我的母語。

UPD
jsonStr:

[ {"id":6,"name":"Martin Ordersky","age":50}, {"id":8,"name":"Linus Torwalds","age":43}, {"id":9,"name":"James Gosling","age":45}, {"id":10,"name":"Bjarne Stroustrup","age":59} ] 

回答

1

我得到完全預期的結果有:

import spray.json._ 

object MyJsonProtocol extends DefaultJsonProtocol { 
    implicit val personFormat: JsonFormat[Person] = jsonFormat3(Person) 
} 

import MyJsonProtocol._ 

val jsonStr = """[{"id":1,"name":"john","age":40}]""" 
val json = jsonStr.parseJson 
val persons = json.convertTo[List[Person]] 
persons.foreach(println) 
+0

我得到了'找不到類型CustomCollectionFormats' – Oleg

+0

對不起..這來自於我們自己的lib .. –

+0

對不起,編輯和不相關的評論..我的scala repl命名空間充滿了左轉.. –