如何使用Play框架解析此JSON？

Question

我從一個web服務返回以下JSON：

{ 
    "hits": [ 
    { 
     "created_at": "2016-02-01T15:01:03.000Z", 
     "title": "title", 
     "num_comments": 778, 
     "parent_id": null, 
     "_tags": [ 
     "story", 
     "author", 
     "story_11012044" 
     ], 
     "objectID": "11012044", 
     "_highlightResult": { 
     "title": { 
      "value": "title", 
      "matchLevel": "full", 
      "matchedWords": [ 
      "title" 
      ] 
     }, 
     "author": { 
      "value": "author", 
      "matchLevel": "none", 
      "matchedWords": [ 

      ] 
     }, 
     "story_text": { 
      "value": "Please lead", 
      "matchLevel": "none", 
      "matchedWords": [ 

      ] 
     } 
     } 
    } 
    ] 
} 

，我試圖在遊戲框架使用JSON解析庫解析它。我有以下代碼：

import play.api.libs.functional.syntax._ 
import play.api.libs.json._ 
case class Post(id: Long, date: String, count: Int) 
object Post { 

    implicit val postFormat = Json.format[Post] 
    implicit val writes: Writes[Post] = (
    (JsPath \ "id").write[Long] and 
    (JsPath \"date").write[String] and 
    (JsPath \ "count").write[Int] 
)(unlift(Post.unapply)) 

    implicit val reads: Reads[Post] = (
    (JsPath \ "objectID").read[Long] and 
    (JsPath \ "created_at").read[String] and 
    (JsPath \ "num_comments").read[Int] 
)(Post.apply _) 
} 

import play.api.libs.json._ 
class PostRepo { 
    val request: WSRequest = ws.url(MY_URL) 

    def getPosts: Future[Seq[Post]] = 
    val result: Future[JsValue] = request.get().map(response => 
     response.status match { 
      case 200 => Json.parse(response.body) 
      case _ => throw new Exception("Web service call failed: " + response.body) 
    }) 
    result.map({ 
     jsonvalue => println("JSARRAY: " + jsonvalue); 
     (jsonvalue \ "hits").as[Seq[Post]] 
    }) 
    result 
} 

現在，當我運行代碼，我收到以下錯誤：

play.api.http.HttpErrorHandlerExceptions$$anon$1: Execution exception[[JsResultException: 

JsResultException(errors:List(((0)/date,List(ValidationError(List(error.path.missing),WrappedArray()))), ((0)/count,List(ValidationError(List(error.path.missing),WrappedArray()))), ((0)/id,List(ValidationError(List(error.path.missing),WrappedArray()))), ((1)/date,List(ValidationError(List(error.path.missing),WrappedArray()))), ((1)/count,List(ValidationError(List(error.path.missing),WrappedArray()))), ((1)/id,List(ValidationError(List(error.path.missing),WrappedArray()))), ((2)/date,List(ValidationError(List(error.path.missing),WrappedArray()))), ((2)/count,List(ValidationError(List(error.path.missing),WrappedArray()))), ((2)/id,List(ValidationError(List(error.path.missing),WrappedArray()))), ((3)/date,List(ValidationError(List(error.path.missing),WrappedArray()))), ((3)/count,List(ValidationError(List(error.path.missing),WrappedArray()))), ((3)/id,List(ValidationError(List(error.path.missing),WrappedArray())))

顯然東西是錯誤的我試圖解析JSON的方式但我現在花了幾個小時試圖弄清楚這個問題，並且我很好並且堅持不懈。

Answer 1

與Reads.seq

val r = (__ \ "hits").read[Seq[Post]](Reads.seq[Post]) 

def getPosts: Future[Seq[Post]] = { 
    WS.url(MY_URL).get().map(response => 
    response.status match { 
     case 200 => r.reads(response.json) match { 
     case JsError(e) => throw new Exception("Json read fails. Response body:" + response.json.toString() + "\nRead error:" + e.toString()) 
     case JsSuccess(x, _) => x 
     } 
     case _ => throw new Exception("Web service call failed: " + response.body) 
    }) 
}