scala – Chill-kryo中的例外情况

2023年1月11日 353次阅读

我试图从这个
link 运行Chill-Scala的示例代码

我有两个虚拟案例类

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

这是我从这个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,当我运行此代码时,它给了我java.lang.InstantiationError：scala.runtime.Nothing $exception

这里有完整的堆栈跟踪

Running kryotest.Main

********** serializing

********** Deserializing
[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] Stack
trace suppressed: run last compile:run for the full output.
java.lang.RuntimeException: Nonzero exit code: 1 at
scala.sys.package$.error(package.scala:27) [trace] Stack trace
suppressed: run last compile:run for the full output. [error]
(compile:run) Nonzero exit code: 1 [error] Total time: 4 s, completed
Aug 31, 2015 3:15:54 PM

请告诉我,我做错了什么？

编辑：当我从fromBytes方法替换以下行时

val t = kryo.readObject(i,m.runtimeClass.asInstanceOf [Class [Student]])

同

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

我不会兴奋地知道修改后发生了什么,但它没有给我异常,但方法返回None而不是对象

修改后的输出

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

最佳答案 由于您的示例的git存储库中的示例的第一行说Chill现在支持Scala 2.11.请改用它.

使用chill from twitter可以轻松地序列化scala对象

这是他们所说的：

Chill-bijection

Bijections and Injections are useful when considering serialization.
If you have an Injection from T to Array[Byte] you have a
serialization. Additionally, if you have a Bijection between A and B,
and a serialization for B, then you have a serialization for A. See
BijectionEnrichedKryo for easy interop between bijection and chill.
KryoInjection: easy serialization to byte Arrays

KryoInjection is an injection from Any to Array[Byte]. To serialize
using it:

import com.twitter.chill.KryoInjection

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

KryoInjection can be composed with Bijections and Injections from
com.twitter.bijection.

所以我重写了你的主要课程：

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)

}

并为您的build.sbt使用此：

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

最后我得到了这个结果：

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