pattern matching fails on second try

问题

I am using the following code to pattern match an instance of PrivateKey:

import java.security.interfaces.{RSAPrivateKey, RSAPublicKey}
import java.security.{PrivateKey, PublicKey} 

object ClientPrivateKey {
  def apply(privateKey: PrivateKey) = privateKey match {
    case k: RSAPrivateKey ⇒ RSAClientPrivateKey(k)
    case k: EdDSAPrivateKey ⇒ EDCClientPrivateKey(k)
  }
}

val pk: PrivateKey = ....
ClientPrivateKey(pk)

I am getting a weird behavior when running tests with sbt ~test. On the first run the test passes, on subsequent tries, without restarting sbt, the test fails with:

[info]   scala.MatchError: net.i2p.crypto.eddsa.EdDSAPrivateKey@e5d5feef (of class net.i2p.crypto.eddsa.EdDSAPrivateKey)
[info]   at com.advancedtelematic.libtuf.data.ClientDataType$ClientPrivateKey$.apply(ClientDataType.scala:39)
[info]   at com.advancedtelematic.tuf.keyserver.daemon.KeyGenerationOp$$anonfun$saveToVault$1.apply(KeyGeneratorLeader.scala:122)
[info]   at com.advancedtelematic.tuf.keyserver.daemon.KeyGenerationOp$$anonfun$saveToVault$1.apply(KeyGeneratorLeader.scala:121)
[info]   at scala.concurrent.Future$$anonfun$traverse$1.apply(Future.scala:576)
[info]   at scala.concurrent.Future$$anonfun$traverse$1.apply(Future.scala:575)
[info]   at scala.collection.TraversableOnce$$anonfun$foldLeft$1.apply(TraversableOnce.scala:157)
[info]   at scala.collection.TraversableOnce$$anonfun$foldLeft$1.apply(TraversableOnce.scala:157)

Which is strange, as net.i2p.crypto.eddsa.EdDSAPrivateKey matches the type of the object being matched.

What can be interfering with this pattern matching?

回答1:

One thing that comes to my mind is that your privateKey might be coming from a different classloader that the one used by default by your pattern matching code.

You can test this e.g. like that:

def apply(privateKey: PrivateKey) = privateKey match {
  case k: RSAPrivateKey ⇒ RSAClientPrivateKey(k)
  case k: EdDSAPrivateKey ⇒ EDCClientPrivateKey(k)
  case k if k.getClass.getName == classOf[EdDSAPrivateKey].getName =>
    val sameClasses = k.getClass == classOf[EdDSAPrivateKey]
    val sameClasses = k.getClass.getClassLoader == classOf[EdDSAPrivateKey].getClassLoader
    throw new Exception(s"Different class loaders? $sameClasses $sameClassLoaders")
}

来源：https://stackoverflow.com/questions/44822228/pattern-matching-fails-on-second-try

标签

scala

jce