Question

如何使用 Kryo 反序列化不可变集合？除了我所做的以外，我还需要注册一些东西吗？

这是我的示例代码

import com.esotericsoftware.kryo.Kryo
import com.esotericsoftware.kryo.io.Input
import com.esotericsoftware.kryo.io.Output
import com.romix.scala.serialization.kryo._

val kryo = new Kryo

// Serialization of Scala maps like Trees, etc
kryo.addDefaultSerializer(classOf[scala.collection.Map[_,_]], classOf[ScalaMapSerializer])
kryo.addDefaultSerializer(classOf[scala.collection.generic.MapFactory[scala.collection.Map]], classOf[ScalaMapSerializer])

// Serialization of Scala sets
kryo.addDefaultSerializer(classOf[scala.collection.Set[_]], classOf[ScalaSetSerializer])
kryo.addDefaultSerializer(classOf[scala.collection.generic.SetFactory[scala.collection.Set]], classOf[ScalaSetSerializer])

// Serialization of all Traversable Scala collections like Lists, Vectors, etc
kryo.addDefaultSerializer(classOf[scala.collection.Traversable[_]], classOf[ScalaCollectionSerializer])

val filename = "c:\\aaa.bin"
val ofile = new FileOutputStream(filename)
val output2 = new BufferedOutputStream(ofile)
val output = new Output(output2)
kryo.writeClassAndObject(output, List("Test1", "Test2"))
output.close()

val ifile = new FileInputStream(filename)
val input = new Input(new BufferedInputStream(ifile))
val deserialized = kryo.readClassAndObject(input)
input.close()

抛出异常

Exception in thread "main" com.esotericsoftware.kryo.KryoException: Class cannot be created (missing no-arg constructor): scala.collection.immutable.$colon$colon

Answer 1

试试这个，因为它对我有用：

import com.esotericsoftware.kryo.Kryo
import com.esotericsoftware.kryo.io.Input
import com.esotericsoftware.kryo.io.Output
import com.romix.scala.serialization.kryo._
import org.objenesis.strategy.StdInstantiatorStrategy

val kryo = new Kryo

kryo.setRegistrationRequired(false)
kryo.setInstantiatorStrategy(new StdInstantiatorStrategy());
kryo.register(classOf[scala.collection.immutable.$colon$colon[_]],60)
kryo.register(classOf[scala.collection.immutable.Nil$],61)
kryo.addDefaultSerializer(classOf[scala.Enumeration#Value], classOf[EnumerationSerializer])

val filename = "c:\\aaa.bin"
val ofile = new FileOutputStream(filename)
val output2 = new BufferedOutputStream(ofile)
val output = new Output(output2)
kryo.writeClassAndObject(output, List("Test1", "Test2"))
output.close()

val ifile = new FileInputStream(filename)
val input = new Input(new BufferedInputStream(ifile))
val deserialized = kryo.readClassAndObject(input)
input.close()

作为一个FYI，我通过查看romix库的单元测试然后做他们正在做的事情来完成这项工作。

如何使用Kryo反序列化不可变集合？

1 个答案: