Question

如何将List case class作为response投放。

我希望以json的形式给出回复，但无法获得如何将Case of Case Class转换为Json并将其作为回复传递给用户

控制器

def process = Action.async { implicit request =>
    try{
     val data= model1.searching("scala")
     Future(Ok(Json.obj("result" -> "1", "data" ->??)))
    } catch {
      case e: Exception =>
      Future(Ok(Json.obj("result" -> "0"))) //exception occured
    }
  }

模型

case class Team(name: String, image: String, nMember: BigInt, nYear: BigInt)
object model1{
  def searching(term: String) = {
    DB.withConnection { implicit c =>
      val pinfo = SQL("SELECT name,image, no_member, no_year FROM table_name WHERE name like {term} limit 0,9 ").on("term" -> ("%" + term + "%"))()
      var suggestions = List[Team]()
      if (!(pinfo.isEmpty)) {
        suggestions = pinfo.map {
          row =>
            Team(row[String]("name"), row[String]("image"), row[java.math.BigInteger]("no_member"), row[java.math.BigInteger]("no_year"))
        }.toList
      suggestions
    }
  }
}

使用＆＃34;数据＆＃34; - ＆gt;数据

时出现

错误

[error] play - Cannot invoke the action, eventually got an error: scala.MatchError: ((result,success),(data,Team(publicBoard(The Best Car Of 2014 in India,28361273218382137,2014,198), Team(the best book,191919199199119,6534,12)))) (of class scala.Tuple2)

play.api.Application$$anon$1: Execution exception[[MatchError: ((result,success),(data,List(Team(The Best Car Of 2014 in India,28361273218382137,2014,198), Team(the best book,191919199199119,6534,12)))) (of class scala.Tuple2)]]
    at play.api.Application$class.handleError(Application.scala:293) ~[play_2.10.jar:2.2.0]
    at play.api.DefaultApplication.handleError(Application.scala:399) [play_2.10.jar:2.2.0]
    at play.core.server.netty.PlayDefaultUpstreamHandler$$anonfun$2$$anonfun$applyOrElse$3.apply(PlayDefaultUpstreamHandler.scala:261) [play_2.10.jar:2.2.0]
    at play.core.server.netty.PlayDefaultUpstreamHandler$$anonfun$2$$anonfun$applyOrElse$3.apply(PlayDefaultUpstreamHandler.scala:261) [play_2.10.jar:2.2.0]
    at scala.Option.map(Option.scala:145) [scala-library.jar:na]
    at play.core.server.netty.PlayDefaultUpstreamHandler$$anonfun$2.applyOrElse(PlayDefaultUpstreamHandler.scala:261) [play_2.10.jar:2.2.0]
Caused by: scala.MatchError: ((result,success),(data,List(Team(The Best Car Of 2014 in India,28361273218382137,2014,198), Team(the best book,191919199199119,6534,12)))) (of class scala.Tuple2)
    at net.liftweb.json.Extraction$$anonfun$decompose$1.apply(Extraction.scala:82) ~[lift-json_2.10-2.5.1.jar:2.5.1]
    at net.liftweb.json.Extraction$$anonfun$decompose$1.apply(Extraction.scala:82) ~[lift-json_2.10-2.5.1.jar:2.5.1]
    at scala.collection.TraversableLike$$anonfun$map$1.apply(TraversableLike.scala:244) ~[scala-library.jar:na]
    at scala.collection.TraversableLike$$anonfun$map$1.apply(TraversableLike.scala:244) ~[scala-library.jar:na]
    at scala.collection.immutable.Map$Map1.foreach(Map.scala:109) ~[scala-library.jar:na]
    at scala.collection.TraversableLike$class.map(TraversableLike.scala:244) ~[scala-library.jar:na]

Answer 1

您需要为案例类定义序列化程序，然后转换将自动完成（通过含义）

package controllers

import play.api.libs.json._
import play.api.mvc._

import scala.concurrent.Future
import scala.util.Try

object ProcessController extends Controller {
  case class Team(tech: String, nMember: BigInt, Years: Int)

  object Team {
    implicit val bigIntFormat = new Format[BigInt] {
      override def reads(json: JsValue): JsResult[BigInt] = json.validate[String].flatMap { s =>
        Try(BigInt(s)).map(v => JsSuccess(v)).getOrElse(JsError(s"$s is not a number"))
      }

      override def writes(o: BigInt): JsValue = JsString(o.toString)
    }
    implicit val teamformat = Json.format[Team]
  }

  def process = Action.async { implicit request =>
    val data = List(Team("scala", 12, 1), Team("java", 20, 5))
    Future(Ok(Json.obj("result" -> "1", "data" -> data)))
  }
}

我冒昧地使用Int而不是Integer来利用默认播放序列化器。

调用时，动作将生成以下json

{
  "result": "1",
  "data": [
    {
      "tech": "scala",
      "nMember": "12",
      "Years": 1
    },
    {
      "tech": "java",
      "nMember": "20",
      "Years": 5
    }
  ]
}

作为响应的Json案例类列表

1 个答案: