提问者:小点点

Chill-kryo中的异常


我正在尝试从这个链接运行Chill Scala的示例代码

我有两堂假案课

一个是用户

@SerialVersionUID(1)
case class User(name :String, age : Int) extends Serializable 

另一个是学生

@SerialVersionUID(2)
case class Student(sub : String , id : Int , user : User) extends Serializable

下面是我根据这个github示例twitter/chill repo修改的序列化代码

object SeriDeseri {
  private val kryo = {
    val a = KryoSerializer.registerAll
    val k = new Kryo
    a(k)
    k
  }

  def toBytes(student : Student): Array[Byte] = {
    println("********** serializing")
    val b = new ByteArrayOutputStream
    val o = new Output(b)
    kryo.writeObject(o, student)
    o.close()
    b.toByteArray
  }

  def fromBytes[Student](bytes: Array[Byte])(implicit m: Manifest[Student]): Option[Student] = {
    println("********** Deserializing")
    val i = new Input(bytes)
    try {
      val t = kryo.readObject(i, m.runtimeClass.asInstanceOf[Class[Student]])
      Option(t)
    } catch {
      case NonFatal(e) => None
    } finally {
      i.close()
    }
  }
}

这是我的Main类的代码

val user = new User( "Ahsen", 14)
val stu = new Student("oop", 12, user)

  val serial : Array[Byte] = SeriDeseri.toBytes(stu)
  val deserial :Option[Student] = SeriDeseri.fromBytes(serial)
  val obj  = deserial match{
    case Some(objec) => println(objec)
    case None => println("----------- Nothing was deserialized")
  }

现在的问题是,当我运行这段代码时,它给了我java.lang.InstantiationError:scala.runtime.Nothing$异常

这里是完整的堆栈痕迹

[info]运行kryotest. Main

********** 序列化

反序列化 [error] (run-main-0) java.lang.InstantiationError: scala.runtime.Nothing$ java.lang.InstantiationError: scala.runtime.Nothing$ at scala.runtime.Nothing$ConstructorAccess.newInstance(Unknown Source) at com.esotericsoftware.kryo.Kryo$DefaultInstantiatorStrategy$1.newInstance(Kryo.java:1193) at com.esotericsoftware.kryo.Kryo.newInstance(Kryo.java:1061) at com.esotericsoftware.kryo.serializers.FieldSerializer.create(FieldSerializer.java:547)at com.esotericsoftware.kryo.serializers.FieldSerializer.read(FieldSerializer.java:523) at com.esotericsoftware.kryo.Kryo.readObject(Kryo.java:657) at com.test.hcast_serializer.SeriDeseri$.fromBytes(SeriDeseri.scala:32) at kryotest.Main$.delayedEndpoint$kryotest$Main$1(Main.scala:31) at kryotest.Main$delayedInit$body.apply(Main.scala:9) at scala.Function0$class.apply$mcV$sp(Function0.scala:40) 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$1.apply(App.scala:76) at scala.collection.immutable.List.foreach(List.scala:383) at scala.collection.generic.TraversableForwarder$class.foreach(TraversableForwarder.scala:35) at scala.App$class.main(App.scala:76) at kryotest.Main$.main(Main.scala:9) at kryotest.Main.main(Main.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) [trace] 堆栈跟踪抑制:运行上次编译:运行完整输出。java.lang.RuntimeException: Nonzero exit code: 1 at scala.sys.package$.error(package.scala:27) [trace] 堆栈跟踪抑制:运行上次编译:运行完整输出。[错误](编译:运行)非零退出代码:1 [错误] 总时间:4 秒,已完成 2015-8-31下午03:15:54

请告诉我我做错了什么?

编辑:当我从fromBytes方法替换以下行时

< code>val t = kryo.readObject(i,m . runtime Class . as instance of[Class[Student]])

val t = kryo.readClassAndObject(i).asInstanceOf[Student]

我不知道修改后发生了什么,但它没有给我异常,但方法返回了None而不是对象

修改后的输出

********** serializing
********** Deserializing
----------- Nothing was deserialized

共1个答案

匿名用户

由于示例的git存储库中示例的第一行表示Chill现在支持Scala 2.11。请改用它。

有一种简单的方法可以使用 twitter 上的 chill 序列化 scala 对象

以下是他们所说的:

冷双射

双射和注入在考虑序列化时很有用。如果您有从T到Array[Byte]的注入,则有序列化。此外,如果您有A和B之间的双射,以及B的序列化,那么您有A的序列化。有关双射和冷却之间的轻松互操作,请参阅Bij的EnrichedKryo。Kryo注入:字节数组的轻松序列化

Kryo注射液是从任何到Array[Byte]的注入。要使用它进行序列化:

import com . Twitter . chill . kryoinjection

val bytes:Array[Byte]= KryoInjection(some item)val try decode:Scala . util . try[Any]= KryoInjection . invert(bytes)

KryoInjection可以与Bijections和来自com.twitter.bijection的Injections组合。

所以我重写了你的主类:

object Main extends App {

  val user = new User( "Ahsen", 14)
  val stu = new Student("oop", 12, user)



  val bytes:  Array[Byte]    = KryoInjection(stu)

  println("Serialized byte array:" + bytes)

  val tryDecode: scala.util.Try[Any] = KryoInjection.invert(bytes)

  println(tryDecode)

}

和你的身材。sbt使用此项:

"com.twitter" % "chill-bijection_2.11" % "0.7.0"

最后我得到这个结果:

[info] Running chill.Main 
Serialized byte array:[B@17e5b410
Success(Student(oop,12,User(Ahsen,14)))