Pickling Java classes yields empty objects

[andrewwilson]

Hi,
It seems that java classes aren't currently well handled, when attempting to either pickle directly, or say embedded in fields of pure scala classes.
The examples below compile successfully, and generate pickled representations.

However in each case:
a) unpickling to the specific type, successfully returns an object, however it's incorrectly initialised. (i.e. it's fields don't match those of the original object)

b) unpickling to [Any] fails at runtime.

This is rather unfortunate, since particularly case (a) could lead to hard to detect errors.
It would be great if you could take a look.

package picklingtests
import scala.pickling._
import scala.pickling.json._

import org.joda.time.LocalDate

import org.junit._
import org.junit.Assert._

case class X(date: org.joda.time.LocalDate)

class PickleTest {

  @Test def testPickleCaseClassJavaField_Specific = {
    val dt = LocalDate.now().plusDays(3)
    val x = X(dt)
    val pickled = x.pickle
    println(pickled)
    val restored = pickled.unpickle[X]

    assertEquals(x, restored)
  }

    @Test def testPickleCaseClassJavaField_Any = {
    val dt = LocalDate.now().plusDays(3)
    val x = X(dt)
    val pickled = x.pickle
    println(pickled)
    val restored = pickled.unpickle[Any]

    assertEquals(x, restored)
  }


  @Test def testPickleJavaClass_Any = {
    val x = LocalDate.now().plusDays(3)
    val pickled = x.pickle
    println(pickled)
    val restored = pickled.unpickle[Any]

    assertEquals(x, restored)
  }

  @Test def testPickleJavaClass_Specific = {
    val x = LocalDate.now().plusDays(3)
    val pickled = x.pickle
    println(pickled)
    val restored = pickled.unpickle[LocalDate]

    assertEquals(x, restored)
  }

  @Test def testPickleJavaClass2_Any = {
    val x = new java.awt.Rectangle(1, 2, 3, 4)
    val pickled = x.pickle
    println(pickled)
    val restored = pickled.unpickle[Any]

    assertEquals(x, restored)
  }

  @Test def testPickleJavaClass2_Specific = {
    val x = new java.awt.Rectangle(1, 2, 3, 4)
    val pickled = x.pickle
    println(pickled)
    val restored = pickled.unpickle[java.awt.Rectangle]

    assertEquals(x, restored)
  }

}

Output:

JSONPickle({
  "tpe": "picklingtests.X",
  "date": {

  }
})
JSONPickle({
  "tpe": "picklingtests.X",
  "date": {

  }
})
JSONPickle({
  "tpe": "java.awt.Rectangle"
})
JSONPickle({
  "tpe": "org.joda.time.LocalDate"
})
JSONPickle({
  "tpe": "org.joda.time.LocalDate"
})
JSONPickle({
  "tpe": "java.awt.Rectangle"
})

picklingtests.PickleTest

testPickleCaseClassJavaField_Specific(picklingtests.PickleTest)
java.lang.AssertionError: expected:<X(2013-10-24)> but was:<X(2013-10-21)>


testPickleCaseClassJavaField_Any(picklingtests.PickleTest)
java.util.NoSuchElementException: key not found: x$1
    at scala.collection.MapLike$class.default(MapLike.scala:228)
    at scala.collection.AbstractMap.default(Map.scala:58)
    at scala.collection.MapLike$class.apply(MapLike.scala:141)
    at scala.collection.AbstractMap.apply(Map.scala:58)
    at scala.pickling.json.JSONPickleReader.readField(JSONPickleFormat.scala:235)
    at scala.pickling.json.JSONPickleReader.readField(JSONPickleFormat.scala:159)
    at scala.pickling.InterpretedUnpicklerRuntime$$anon$2$$anonfun$fieldVals$1$1.apply(Runtime.scala:174)



testPickleJavaClass2_Specific(picklingtests.PickleTest)
java.lang.AssertionError: expected:<java.awt.Rectangle[x=1,y=2,width=3,height=4]> but was:<java.awt.Rectangle[x=0,y=0,width=0,height=0]>


testPickleJavaClass_Any(picklingtests.PickleTest)
java.util.NoSuchElementException: key not found: x$1
    at scala.collection.MapLike$class.default(MapLike.scala:228)
    at scala.collection.AbstractMap.default(Map.scala:58)
    at scala.collection.MapLike$class.apply(MapLike.scala:141)
    at scala.collection.AbstractMap.apply(Map.scala:58)
    at scala.pickling.json.JSONPickleReader.readField(JSONPickleFormat.scala:235)
    at scala.pickling.json.JSONPickleReader.readField(JSONPickleFormat.scala:159)

testPickleJavaClass_Specific(picklingtests.PickleTest)
java.lang.AssertionError: expected:<2013-10-24> but was:<2013-10-21>


testPickleJavaClass2_Any(picklingtests.PickleTest)
java.util.NoSuchElementException: key not found: x$1
    at scala.collection.MapLike$class.default(MapLike.scala:228)
    at scala.collection.AbstractMap.default(Map.scala:58)
    at scala.collection.MapLike$class.apply(MapLike.scala:141)
    at scala.collection.AbstractMap.apply(Map.scala:58)
    at scala.pickling.json.JSONPickleReader.readField(JSONPickleFormat.scala:235)
    at scala.pickling.json.JSONPickleReader.readField(JSONPickleFormat.scala:159)
    at scala.pickling.InterpretedUnpicklerRuntime$$anon$2$$anonfun$fieldVals$1$1.apply(Runtime.scala:174)

[debop]

I have same problem.

[zen0wu]

Same here, unpickle a pickled java object yields an empty object.