Bending JAXB to the will of Scala [2/2]

jaxb-in-scala-2_01.scala

import scala.annotation.target.field
 
import javax.xml.bind.annotation._
import javax.xml.bind.annotation.adapters._

type xmlElement     = XmlElement @field
type xmlTypeAdapter = XmlJavaTypeAdapter @field

/**
 * NB As with the CustomOptionAdapter we've had to modify the type signature here,
 * https://github.com/krasserm/eventsourcing-example/blob/play-blog/modules/service/src/main/scala/dev/example/eventsourcing/util/Binding.scala
 * because of the bug in MOXy requiring that the first type parameter of the List Adapter 
 * be the same as the first type parameter of XmlAdapter
 */
abstract class AbstractListAdapter[B <: AbstractList[A], A] extends XmlAdapter[B, List[A]] {
  import scala.collection.JavaConverters._

  def marshal(v: List[A]) = {
    if (v == null) {
      create(new ArrayList[A])
    } else create(v.asJava)
  }
  def unmarshal(v: B) = {
    v.elem.asScala.toList
  }
  def create(l: JList[A]): B
}

trait AbstractList[A] {
  def elem: JList[A]
}
 
object Person {
 import java.util.{List => JList}

 class PersonsAdapter extends AbstractListAdapter[PersonItems,Person] {
   def create(l: JList[Person]) = new PersonItems(l)
 }

 @XmlAccessorType(XmlAccessType.FIELD)
 case class PersonItems(@xmlElementRef(name = "person") elem: JList[Person]) extends AbstractList[Person] {
   def this() = this(null)
 }
}

@XmlRootElement
@XmlAccessorType(XmlAccessType.FIELD)
case class Person(name:String){

  private def this() = this("")
}

@XmlRootElement
@XmlAccessorType(XmlAccessType.FIELD)
case class Entry(@xmlElement id:String,
                 @xmlTypeAdapter(classOf[Person.PersonsAdapter]) authors:List[Person]= List()) {

  private def this() = this("", List())                  
}

jaxb-in-scala-2_02.txt

java.lang.ClassCastException: scala.collection.immutable.$colon$colon cannot be cast to java.util.Collection
	at org.eclipse.persistence.internal.queries.CollectionContainerPolicy.iteratorFor(CollectionContainerPolicy.java:150)
	at org.eclipse.persistence.internal.oxm.XMLCompositeDirectCollectionMappingNodeValue.marshal(XMLCompositeDirectCollectionMappingNodeValue.java:78)
	at org.eclipse.persistence.internal.oxm.NodeValue.marshal(NodeValue.java:149)
	at org.eclipse.persistence.internal.oxm.NodeValue.marshal(NodeValue.java:102)
	at org.eclipse.persistence.internal.oxm.record.ObjectMarshalContext.marshal(ObjectMarshalContext.java:59)
	at org.eclipse.persistence.internal.oxm.XPathNode.marshal(XPathNode.java:401)
	at org.eclipse.persistence.internal.oxm.XPathObjectBuilder.buildRow(XPathObjectBuilder.java:240)
	at org.eclipse.persistence.internal.oxm.TreeObjectBuilder.buildRow(TreeObjectBuilder.java:118)
	at org.eclipse.persistence.internal.oxm.TreeObjectBuilder.buildRow(TreeObjectBuilder.java:1)
	at org.eclipse.persistence.internal.oxm.XMLMarshaller.marshal(XMLMarshaller.java:751)

jaxb-in-scala-2_03.scala

import scala.annotation.target.field
 
import javax.xml.bind.annotation._
import javax.xml.bind.annotation.adapters._

import scala.collection.mutable
import scala.runtime.ScalaRunTime

type xmlElement     = XmlElement @field

@XmlRootElement
@XmlAccessorType(XmlAccessType.FIELD)
case class Person(name:String) {

  private def this() = this("")
}

@XmlRootElement
@XmlAccessorType(XmlAccessType.FIELD)
case class Entry(id:String, author:Array[Person] = Array[Person]()) {

  private def this() = this("", Array[Person]())

  def productArity = 2

  def productElement(n: Int): Any = n match {
    case 0 => id
    case 1 => mutable.WrappedArray.make(contributor)
    case _ => throw new IndexOutOfBoundsException(n.toString)
  }

  override def equals(that: Any) = ScalaRunTime._equals(this, that)
}