json - 无法使用spray-json解码json HttpEntity

Question

我正在尝试运行 documentation 中的简单示例没有任何变化:

import spray.json.DefaultJsonProtocol
import spray.httpx.unmarshalling._
import spray.httpx.marshalling._
import spray.http._
import HttpCharsets._
import MediaTypes._

case class Person(name: String, firstName: String, age: Int)

object MyJsonProtocol extends DefaultJsonProtocol {
  implicit val PersonFormat = jsonFormat3(Person)
}

import MyJsonProtocol._
import spray.httpx.SprayJsonSupport._
import spray.util._

val bob = Person("Bob", "Parr", 32)
val body = HttpEntity(
  contentType = ContentType(`application/json`, `UTF-8`),
  string =
"""|{
  |  "name": "Bob",
  |  "firstName": "Parr",
  |  "age": 32
  |}""".stripMarginWithNewline("\n")
)

marshal(bob)
body.as[Person]

它在最后一行(“body.as[Person]”)失败，并出现以下错误和堆栈跟踪:

Exception in thread "main" java.lang.NoSuchMethodError: spray.json.JsonParser$.apply(Ljava/lang/String;)Lspray/json/JsValue;
    at spray.httpx.SprayJsonSupport$$anonfun$sprayJsonUnmarshaller$1.applyOrElse(SprayJsonSupport.scala:36)
    at spray.httpx.SprayJsonSupport$$anonfun$sprayJsonUnmarshaller$1.applyOrElse(SprayJsonSupport.scala:34)
    at scala.runtime.AbstractPartialFunction.apply(AbstractPartialFunction.scala:36)
    at spray.httpx.unmarshalling.Unmarshaller$$anon$1$$anonfun$unmarshal$1.apply(Unmarshaller.scala:29)
    at spray.httpx.unmarshalling.SimpleUnmarshaller.protect(SimpleUnmarshaller.scala:40)
    at spray.httpx.unmarshalling.Unmarshaller$$anon$1.unmarshal(Unmarshaller.scala:29)
    at spray.httpx.unmarshalling.SimpleUnmarshaller.apply(SimpleUnmarshaller.scala:29)
    at spray.httpx.unmarshalling.SimpleUnmarshaller.apply(SimpleUnmarshaller.scala:23)
    at spray.httpx.unmarshalling.package$PimpedHttpEntity.as(package.scala:39)
    at com.example.M1$.delayedEndpoint$com$example$M1$1(M1.scala:34)
    at com.example.M1$delayedInit$body.apply(M1.scala:3)
    at scala.Function0$class.apply$mcV$sp(Function0.scala:34)
    at scala.runtime.AbstractFunction0.apply$mcV$sp(AbstractFunction0.scala:12)
    at scala.App$$anonfun$main$1.apply(App.scala:76)
    at scala.App$$anonfun$main$1.apply(App.scala:76)
    at scala.collection.immutable.List.foreach(List.scala:381)
    at scala.collection.generic.TraversableForwarder$class.foreach(TraversableForwarder.scala:35)
    at scala.App$class.main(App.scala:76)
    at com.example.M1$.main(M1.scala:3)
    at com.example.M1.main(M1.scala)
    at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
    at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
    at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
    at java.lang.reflect.Method.invoke(Method.java:497)
    at com.intellij.rt.execution.application.AppMain.main(AppMain.java:140)

我的代码有什么问题？我的依赖项如下(build.sbt):

scalaVersion := "2.11.7"

libraryDependencies ++= Seq(
  "io.spray" %% "spray-can" % "1.3.1",
  "io.spray" %% "spray-routing" % "1.3.1",
  "io.spray" %% "spray-json" % "1.3.2",
  "com.typesafe.akka" %% "akka-actor" % "2.3.11"
)

我找到了一个 bug与spray-httpx 和spray-json 不兼容有关，不过好像已经解决了。我正在使用所有库的最新稳定版本。

还有什么问题？

Answer 1

看起来是spray-http 和spray-json 之间的版本不兼容问题，这些特定版本运行良好，没有任何问题:

libraryDependencies ++= Seq(
  "io.spray" %% "spray-can" % "1.3.3",
  "io.spray" %% "spray-routing" % "1.3.3",
  "io.spray" %% "spray-json" % "1.3.2",
  "com.typesafe.akka" %% "akka-actor" % "2.3.11"
)