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Scala example source code file (JavaMirrors.scala)

This example Scala source code file (JavaMirrors.scala) is included in my "Source Code Warehouse" project. The intent of this project is to help you more easily find Scala source code examples by using tags.

All credit for the original source code belongs to; I'm just trying to make examples easier to find. (For my Scala work, see my Scala examples and tutorials.)

Scala tags/keywords

any, classsymbol, collection, genericdeclaration, list, methodsymbol, modulesymbol, mutable, nosymbol, reflection, runtime, string, symbol, type

The JavaMirrors.scala Scala example source code

package scala
package reflect
package runtime

import scala.ref.WeakReference
import scala.collection.mutable.WeakHashMap

import java.lang.{Class => jClass, Package => jPackage}
import java.lang.reflect.{
  Method => jMethod, Constructor => jConstructor, Field => jField,
  Member => jMember, Type => jType, TypeVariable => jTypeVariable, Array => jArray,
  AccessibleObject => jAccessibleObject,
  GenericDeclaration, GenericArrayType, ParameterizedType, WildcardType, AnnotatedElement }
import java.lang.annotation.{Annotation => jAnnotation}
import scala.reflect.internal.{ MissingRequirementError, JavaAccFlags, JMethodOrConstructor }
import internal.pickling.ByteCodecs
import internal.pickling.UnPickler
import scala.collection.mutable.{ HashMap, ListBuffer, ArrayBuffer }
import internal.Flags._
import ReflectionUtils._
import scala.language.existentials
import scala.runtime.{ScalaRunTime, BoxesRunTime}

private[scala] trait JavaMirrors extends internal.SymbolTable with api.JavaUniverse with TwoWayCaches { thisUniverse: SymbolTable =>

  private lazy val mirrors = new WeakHashMap[ClassLoader, WeakReference[JavaMirror]]()

  private def createMirror(owner: Symbol, cl: ClassLoader): Mirror = {
    val jm = new JavaMirror(owner, cl)
    mirrors(cl) = new WeakReference(jm)

  override type Mirror = JavaMirror
  implicit val MirrorTag: ClassTag[Mirror] = ClassTag[Mirror](classOf[JavaMirror])

  override lazy val rootMirror: Mirror = createMirror(NoSymbol, rootClassLoader)

  // overriden by ReflectGlobal
  def rootClassLoader: ClassLoader = this.getClass.getClassLoader

  trait JavaClassCompleter

  def runtimeMirror(cl: ClassLoader): Mirror = gilSynchronized {
    mirrors get cl match {
      case Some(WeakReference(m)) => m
      case _ => createMirror(rootMirror.RootClass, cl)

  /** The API of a mirror for a reflective universe */
  class JavaMirror(owner: Symbol,
    /* Class loader that is a mastermind behind the reflexive mirror */
    val classLoader: ClassLoader
  ) extends Roots(owner) with super.JavaMirror { thisMirror =>

    val universe: thisUniverse.type = thisUniverse

    import definitions._
    private[reflect] lazy val runDefinitions = new definitions.RunDefinitions // only one "run" in the reflection universe
    import runDefinitions._

    override lazy val RootPackage = (new RootPackage with SynchronizedTermSymbol).markFlagsCompleted(mask = AllFlags)
    override lazy val RootClass = (new RootClass with SynchronizedModuleClassSymbol).markFlagsCompleted(mask = AllFlags)
    override lazy val EmptyPackage = (new EmptyPackage with SynchronizedTermSymbol).markFlagsCompleted(mask = AllFlags)
    override lazy val EmptyPackageClass = (new EmptyPackageClass with SynchronizedModuleClassSymbol).markFlagsCompleted(mask = AllFlags)

    /** The lazy type for root.
    override lazy val rootLoader = new LazyType with FlagAgnosticCompleter {
      override def complete(sym: Symbol) = sym setInfo new LazyPackageType

    // reflective mirrors can't know the exhaustive list of available packages
    // (that's because compiler mirrors are based on directories and reflective mirrors are based on classloaders,
    // and unlike directories classloaders might make up stuff on the fly)
    // hence we need to be optimistic and create packages out of thin air
    // the same thing is done by the `missingHook` below
    override def staticPackage(fullname: String): ModuleSymbol =
      try super.staticPackage(fullname)
      catch { case _: ScalaReflectionException => makeScalaPackage(fullname) }

// ----------- Caching ------------------------------------------------------------------

    private val classCache       = new TwoWayCache[jClass[_], ClassSymbol]
    private val packageCache     = new TwoWayCache[Package, ModuleSymbol]
    private val methodCache      = new TwoWayCache[jMethod, MethodSymbol]
    private val constructorCache = new TwoWayCache[jConstructor[_], MethodSymbol]
    private val fieldCache       = new TwoWayCache[jField, TermSymbol]
    private val tparamCache      = new TwoWayCache[jTypeVariable[_ <: GenericDeclaration], TypeSymbol]

    private[runtime] def toScala[J: HasJavaClass, S](cache: TwoWayCache[J, S], key: J)(body: (JavaMirror, J) => S): S =
        val jclazz = implicitly[HasJavaClass[J]] getClazz key
        body(mirrorDefining(jclazz), key)

    private implicit val classHasJavaClass: HasJavaClass[jClass[_]]        = new HasJavaClass(identity)
    private implicit val methHasJavaClass: HasJavaClass[jMethod]           = new HasJavaClass(_.getDeclaringClass)
    private implicit val fieldHasJavaClass: HasJavaClass[jField]           = new HasJavaClass(_.getDeclaringClass)
    private implicit val constrHasJavaClass: HasJavaClass[jConstructor[_]] = new HasJavaClass(_.getDeclaringClass)
    private implicit val tparamHasJavaClass: HasJavaClass[jTypeVariable[_ <: GenericDeclaration]] =
      new HasJavaClass ( (tparam: jTypeVariable[_ <: GenericDeclaration]) => {
        tparam.getGenericDeclaration match {
          case jclazz: jClass[_]        => jclazz
          case jmeth: jMethod           => jmeth.getDeclaringClass
          case jconstr: jConstructor[_] => jconstr.getDeclaringClass

// ----------- Implementations of mirror operations and classes  -------------------

    private def abort(msg: String) = throw new ScalaReflectionException(msg)

    private def ErrorInnerClass(sym: Symbol)                      = abort(s"$sym is an inner class, use reflectClass on an InstanceMirror to obtain its ClassMirror")
    private def ErrorInnerModule(sym: Symbol)                     = abort(s"$sym is an inner module, use reflectModule on an InstanceMirror to obtain its ModuleMirror")
    private def ErrorStaticClass(sym: Symbol)                     = abort(s"$sym is a static class, use reflectClass on a RuntimeMirror to obtain its ClassMirror")
    private def ErrorStaticModule(sym: Symbol)                    = abort(s"$sym is a static module, use reflectModule on a RuntimeMirror to obtain its ModuleMirror")
    private def ErrorNotMember(sym: Symbol, owner: Symbol)        = abort(s"expected a member of $owner, you provided ${sym.kindString} ${sym.fullName}")
    private def ErrorNotField(sym: Symbol)                        = abort(s"expected a field or an accessor method symbol, you provided $sym")
    private def ErrorNotConstructor(sym: Symbol, owner: Symbol)   = abort(s"expected a constructor of $owner, you provided $sym")
    private def ErrorArrayConstructor(sym: Symbol, owner: Symbol) = abort(s"Cannot instantiate arrays with mirrors. Consider using `scala.reflect.ClassTag(<class of element>).newArray(<length>)` instead")
    private def ErrorFree(member: Symbol, freeType: Symbol)       = abort(s"cannot reflect ${member.kindString} ${}, because it's a member of a weak type ${}")
    private def ErrorNonExistentField(sym: Symbol)                = abort(
      sm"""Scala field ${} isn't represented as a Java field, neither it has a Java accessor method
          |note that private parameters of class constructors don't get mapped onto fields and/or accessors,
          |unless they are used outside of their declaring constructors.""")

    /** Helper functions for extracting typed values from a (Class[_], Any)
     *  representing an annotation argument.
    private object toAnnotArg {
      val        StringClass = classOf[String]
      val         ClassClass = classOf[jClass[_]]
      object  PrimitiveClass { def unapply(x: jClass[_]) = x.isPrimitive }
      object       EnumClass { def unapply(x: jClass[_]) = x.isEnum }
      object      ArrayClass { def unapply(x: jClass[_]) = x.isArray }
      object AnnotationClass { def unapply(x: jClass[_]) = x.isAnnotation }

      object ConstantArg {
        def enumToSymbol(enum: Enum[_]): Symbol = {
          val staticPartOfEnum = classToScala(enum.getClass).companionSymbol

        def unapply(schemaAndValue: (jClass[_], Any)): Option[Any] = schemaAndValue match {
          case (StringClass | PrimitiveClass(), value) => Some(value)
          case (ClassClass, value: jClass[_])          => Some(classToScala(value).toType)
          case (EnumClass(), value: Enum[_])           => Some(enumToSymbol(value))
          case _                                       => None
      def apply(schemaAndValue: (jClass[_], Any)): ClassfileAnnotArg = schemaAndValue match {
        case ConstantArg(value)                      => LiteralAnnotArg(Constant(value))
        case (clazz @ ArrayClass(), value: Array[_]) => ArrayAnnotArg(value map (x => apply(ScalaRunTime.arrayElementClass(clazz) -> x)))
        case (AnnotationClass(), value: jAnnotation) => NestedAnnotArg(JavaAnnotationProxy(value))
        case _                                       => UnmappableAnnotArg
    private case class JavaAnnotationProxy(jann: jAnnotation) extends AnnotationInfo {
      override val atp: Type = classToScala(jann.annotationType).toType
      override val args: List[Tree] = Nil
      override def original: Tree = EmptyTree
      override def setOriginal(t: Tree): this.type = throw new Exception("setOriginal inapplicable for " + this)
      override def pos: Position = NoPosition
      override def setPos(pos: Position): this.type = throw new Exception("setPos inapplicable for " + this)
      override def toString = completeAnnotationToString(this)

      // todo. find out the exact order of assocs as they are written in the class file
      // currently I'm simply sorting the methods to guarantee stability of the output
      override lazy val assocs: List[(Name, ClassfileAnnotArg)] = (
        jann.annotationType.getDeclaredMethods.sortBy(_.getName).toList map (m =>
          (m.getName: TermName) -> toAnnotArg(m.getReturnType -> m.invoke(jann))

    def reflect[T: ClassTag](obj: T): InstanceMirror = new JavaInstanceMirror(obj)

    def reflectClass(cls: ClassSymbol): ClassMirror = {
      if (!cls.isStatic) ErrorInnerClass(cls)
      new JavaClassMirror(null, cls)

    def reflectModule(mod: ModuleSymbol): ModuleMirror = {
      if (!mod.isStatic) ErrorInnerModule(mod)
      new JavaModuleMirror(null, mod)

    def runtimeClass(tpe: Type): RuntimeClass = typeToJavaClass(tpe)

    def runtimeClass(cls: ClassSymbol): RuntimeClass = classToJava(cls)

    def classSymbol(rtcls: RuntimeClass): ClassSymbol = classToScala(rtcls)

    def moduleSymbol(rtcls: RuntimeClass): ModuleSymbol = classToScala(rtcls).companionModule.asModule

    private def ensuringNotFree(sym: Symbol)(body: => Any) {
      val freeType = sym.ownerChain find (_.isFreeType)
      freeType match {
        case Some(freeType) => ErrorFree(sym, freeType)
        case _ => body
    private def checkMemberOf(sym: Symbol, owner: ClassSymbol) {
      if (sym.owner == AnyClass || sym.owner == AnyRefClass || sym.owner == ObjectClass) {
        // do nothing
      } else if (sym.owner == AnyValClass) {
        if (!owner.isPrimitiveValueClass && !owner.isDerivedValueClass) ErrorNotMember(sym, owner)
      } else {
        ensuringNotFree(sym) {
          if (!( contains sym.owner)) ErrorNotMember(sym, owner)

    private def checkConstructorOf(sym: Symbol, owner: ClassSymbol) {
      if (!sym.isClassConstructor) ErrorNotConstructor(sym, owner)
      if (owner == ArrayClass) ErrorArrayConstructor(sym, owner)
      ensuringNotFree(sym) {
        if (! ErrorNotConstructor(sym, owner)

    private def preciseClass[T: ClassTag](instance: T) = {
      val staticClazz = classTag[T].runtimeClass
      val dynamicClazz = instance.getClass
      if (staticClazz.isPrimitive) staticClazz else dynamicClazz

    private class JavaInstanceMirror[T: ClassTag](val instance: T) extends InstanceMirror {
      def symbol = thisMirror.classSymbol(preciseClass(instance))
      def reflectField(field: TermSymbol): FieldMirror = {
        checkMemberOf(field, symbol)
        if ((field.isMethod && !field.isAccessor) || field.isModule) ErrorNotField(field)
        val name = if (field.isAccessor) field.localName else
        val field1 = ( decl name).asTerm
        try fieldToJava(field1)
        catch {
          case _: NoSuchFieldException => ErrorNonExistentField(field1)
        new JavaFieldMirror(instance, field1)
      def reflectMethod(method: MethodSymbol): MethodMirror = {
        checkMemberOf(method, symbol)
        mkMethodMirror(instance, method)
      def reflectClass(cls: ClassSymbol): ClassMirror = {
        if (cls.isStatic) ErrorStaticClass(cls)
        checkMemberOf(cls, symbol)
        new JavaClassMirror(instance.asInstanceOf[AnyRef], cls)
      def reflectModule(mod: ModuleSymbol): ModuleMirror = {
        if (mod.isStatic) ErrorStaticModule(mod)
        checkMemberOf(mod, symbol)
        new JavaModuleMirror(instance.asInstanceOf[AnyRef], mod)
      override def toString = s"instance mirror for $instance"

    // caches value class metadata, so that we minimize the work that needs to be done during Mirror.apply
    private class DerivedValueClassMetadata(info: Type) {
      val symbol = info.typeSymbol
      val isDerivedValueClass = symbol.isDerivedValueClass
      lazy val boxer = runtimeClass(symbol.toType).getDeclaredConstructors().head
      lazy val unboxer = {
        val fields @ (field :: _) = symbol.toType.decls.collect{ case ts: TermSymbol if ts.isParamAccessor && ts.isMethod => ts }.toList
        assert(fields.length == 1, s"$symbol: $fields")

    private class JavaFieldMirror(val receiver: Any, val symbol: TermSymbol, metadata: DerivedValueClassMetadata)
            extends FieldMirror {
      def this(receiver: Any, symbol: TermSymbol) = this(receiver, symbol, new DerivedValueClassMetadata(
      def bind(newReceiver: Any) = new JavaFieldMirror(newReceiver, symbol, metadata)
      import metadata._

      lazy val jfield = ensureAccessible(fieldToJava(symbol))
      def get = {
        val value = jfield get receiver
        if (isDerivedValueClass) boxer.newInstance(value) else value
      def set(value: Any) = {
        // it appears useful to be able to set values of vals, therefore I'm disabling this check
        // if (!symbol.isMutable) ErrorSetImmutableField(symbol)
        jfield.set(receiver, if (isDerivedValueClass) unboxer.invoke(value) else value)

      override def toString = s"field mirror for ${showDecl(symbol)} (bound to $receiver)"

    // the "symbol == Any_getClass || symbol == Object_getClass" test doesn't cut it
    // because both AnyVal and its primitive descendants define their own getClass methods
    private def isGetClass(meth: MethodSymbol) = ( string_== "getClass") && meth.paramss.flatten.isEmpty
    private def isStringConcat(meth: MethodSymbol) = meth == String_+ || (meth.owner.isPrimitiveValueClass && meth.returnType =:= StringClass.toType)
    lazy val bytecodelessMethodOwners = Set[Symbol](AnyClass, AnyValClass, AnyRefClass, ObjectClass, ArrayClass) ++ ScalaPrimitiveValueClasses
    lazy val bytecodefulObjectMethods = Set[Symbol](Object_clone, Object_equals, Object_finalize, Object_hashCode, Object_toString,
                                        Object_notify, Object_notifyAll) ++
    private def isBytecodelessMethod(meth: MethodSymbol): Boolean = {
      if (isGetClass(meth) || isStringConcat(meth) || meth.owner.isPrimitiveValueClass || meth == runDefinitions.Predef_classOf || meth.isMacro) return true
      bytecodelessMethodOwners(meth.owner) && !bytecodefulObjectMethods(meth)

    private def isByNameParam(p: Type) = isByNameParamType(p)
    private def isValueClassParam(p: Type) = p.typeSymbol.isDerivedValueClass

    // unlike other mirrors, method mirrors are created by a factory
    // that's because we want to have decent performance
    // therefore we move special cases into separate subclasses
    // rather than have them on a hot path them in a unified implementation of the `apply` method
    private def mkMethodMirror[T: ClassTag](receiver: T, symbol: MethodSymbol): MethodMirror = {
      def existsParam(pred: Type => Boolean) =
      if (isBytecodelessMethod(symbol)) new BytecodelessMethodMirror(receiver, symbol)
      else if (existsParam(isByNameParam) || existsParam(isValueClassParam)) new JavaTransformingMethodMirror(receiver, symbol)
      else {
        symbol.paramss.flatten.length match {
          case 0 => new JavaVanillaMethodMirror0(receiver, symbol)
          case 1 => new JavaVanillaMethodMirror1(receiver, symbol)
          case 2 => new JavaVanillaMethodMirror2(receiver, symbol)
          case 3 => new JavaVanillaMethodMirror3(receiver, symbol)
          case 4 => new JavaVanillaMethodMirror4(receiver, symbol)
          case _ => new JavaVanillaMethodMirror(receiver, symbol)

    private abstract class JavaMethodMirror(val symbol: MethodSymbol, protected val ret: DerivedValueClassMetadata) extends MethodMirror {
      lazy val jmeth = ensureAccessible(methodToJava(symbol))
      lazy val jconstr = ensureAccessible(constructorToJava(symbol))

      def jinvokeraw(args: Seq[Any]) =
        if (!symbol.isConstructor) jmeth.invoke(receiver, args.asInstanceOf[Seq[AnyRef]]: _*)
        else if (receiver == null) jconstr.newInstance(args.asInstanceOf[Seq[AnyRef]]: _*)
        else jconstr.newInstance((receiver +: args).asInstanceOf[Seq[AnyRef]]: _*)
      def jinvoke(args: Seq[Any]): Any = {
        val result = jinvokeraw(args)
        if (!symbol.isConstructor && jmeth.getReturnType == java.lang.Void.TYPE) ()
        else if (!symbol.isConstructor && ret.isDerivedValueClass) ret.boxer.newInstance(result.asInstanceOf[AnyRef])
        else result

      override def toString = {
        val what = if (symbol.isConstructor) "constructor mirror" else "method mirror"
        s"$what for ${showDecl(symbol)} (bound to $receiver)"

    private class JavaVanillaMethodMirror(val receiver: Any, symbol: MethodSymbol, ret: DerivedValueClassMetadata)
            extends JavaMethodMirror(symbol, ret) {
      def this(receiver: Any, symbol: MethodSymbol) = this(receiver, symbol, new DerivedValueClassMetadata(symbol.returnType))
      def bind(newReceiver: Any) = new JavaVanillaMethodMirror(newReceiver, symbol, ret)
      def apply(args: Any*): Any = jinvoke(args)

    private class JavaVanillaMethodMirror0(receiver: Any, symbol: MethodSymbol, ret: DerivedValueClassMetadata)
            extends JavaVanillaMethodMirror(receiver, symbol, ret) {
      def this(receiver: Any, symbol: MethodSymbol) = this(receiver, symbol, new DerivedValueClassMetadata(symbol.returnType))
      override def bind(newReceiver: Any) = new JavaVanillaMethodMirror0(newReceiver, symbol, ret)
      override def jinvokeraw(args: Seq[Any]) =
        if (!symbol.isConstructor) jmeth.invoke(receiver)
        else if (receiver == null) jconstr.newInstance()
        else jconstr.newInstance(receiver.asInstanceOf[AnyRef])

    private class JavaVanillaMethodMirror1(receiver: Any, symbol: MethodSymbol, ret: DerivedValueClassMetadata)
            extends JavaVanillaMethodMirror(receiver, symbol, ret) {
      def this(receiver: Any, symbol: MethodSymbol) = this(receiver, symbol, new DerivedValueClassMetadata(symbol.returnType))
      override def bind(newReceiver: Any) = new JavaVanillaMethodMirror1(newReceiver, symbol, ret)
      override def jinvokeraw(args: Seq[Any]) =
        if (!symbol.isConstructor) jmeth.invoke(receiver, args(0).asInstanceOf[AnyRef])
        else if (receiver == null) jconstr.newInstance(args(0).asInstanceOf[AnyRef])
        else jconstr.newInstance(receiver.asInstanceOf[AnyRef], args(0).asInstanceOf[AnyRef])

    private class JavaVanillaMethodMirror2(receiver: Any, symbol: MethodSymbol, ret: DerivedValueClassMetadata)
            extends JavaVanillaMethodMirror(receiver, symbol, ret) {
      def this(receiver: Any, symbol: MethodSymbol) = this(receiver, symbol, new DerivedValueClassMetadata(symbol.returnType))
      override def bind(newReceiver: Any) = new JavaVanillaMethodMirror2(newReceiver, symbol, ret)
      override def jinvokeraw(args: Seq[Any]) =
        if (!symbol.isConstructor) jmeth.invoke(receiver, args(0).asInstanceOf[AnyRef], args(1).asInstanceOf[AnyRef])
        else if (receiver == null) jconstr.newInstance(args(0).asInstanceOf[AnyRef], args(1).asInstanceOf[AnyRef])
        else jconstr.newInstance(receiver.asInstanceOf[AnyRef], args(0).asInstanceOf[AnyRef], args(1).asInstanceOf[AnyRef])

    private class JavaVanillaMethodMirror3(receiver: Any, symbol: MethodSymbol, ret: DerivedValueClassMetadata)
            extends JavaVanillaMethodMirror(receiver, symbol, ret) {
      def this(receiver: Any, symbol: MethodSymbol) = this(receiver, symbol, new DerivedValueClassMetadata(symbol.returnType))
      override def bind(newReceiver: Any) = new JavaVanillaMethodMirror3(newReceiver, symbol, ret)
      override def jinvokeraw(args: Seq[Any]) =
        if (!symbol.isConstructor) jmeth.invoke(receiver, args(0).asInstanceOf[AnyRef], args(1).asInstanceOf[AnyRef], args(2).asInstanceOf[AnyRef])
        else if (receiver == null) jconstr.newInstance(args(0).asInstanceOf[AnyRef], args(1).asInstanceOf[AnyRef], args(2).asInstanceOf[AnyRef])
        else jconstr.newInstance(receiver.asInstanceOf[AnyRef], args(0).asInstanceOf[AnyRef], args(1).asInstanceOf[AnyRef], args(2).asInstanceOf[AnyRef])

    private class JavaVanillaMethodMirror4(receiver: Any, symbol: MethodSymbol, ret: DerivedValueClassMetadata)
            extends JavaVanillaMethodMirror(receiver, symbol, ret) {
      def this(receiver: Any, symbol: MethodSymbol) = this(receiver, symbol, new DerivedValueClassMetadata(symbol.returnType))
      override def bind(newReceiver: Any) = new JavaVanillaMethodMirror4(newReceiver, symbol, ret)
      override def jinvokeraw(args: Seq[Any]) =
        if (!symbol.isConstructor) jmeth.invoke(receiver, args(0).asInstanceOf[AnyRef], args(1).asInstanceOf[AnyRef], args(2).asInstanceOf[AnyRef], args(3).asInstanceOf[AnyRef])
        else if (receiver == null) jconstr.newInstance(args(0).asInstanceOf[AnyRef], args(1).asInstanceOf[AnyRef], args(2).asInstanceOf[AnyRef], args(3).asInstanceOf[AnyRef])
        else jconstr.newInstance(receiver.asInstanceOf[AnyRef], args(0).asInstanceOf[AnyRef], args(1).asInstanceOf[AnyRef], args(2).asInstanceOf[AnyRef], args(3).asInstanceOf[AnyRef])

    // caches MethodSymbol metadata, so that we minimize the work that needs to be done during Mirror.apply
    // TODO: vararg is only supported in the last parameter list (SI-6182), so we don't need to worry about the rest for now
    private class MethodMetadata(symbol: MethodSymbol) {
      private val params = symbol.paramss.flatten.toArray
      private val vcMetadata = => new DerivedValueClassMetadata(
      val isByName = => isByNameParam(
      def isDerivedValueClass(i: Int) = vcMetadata(i).isDerivedValueClass
      def paramUnboxers(i: Int) = vcMetadata(i).unboxer
      val paramCount = params.length
      val ret = new DerivedValueClassMetadata(symbol.returnType)

    private class JavaTransformingMethodMirror(val receiver: Any, symbol: MethodSymbol, metadata: MethodMetadata)
            extends JavaMethodMirror(symbol, metadata.ret) {
      def this(receiver: Any, symbol: MethodSymbol) = this(receiver, symbol, new MethodMetadata(symbol))
      override def bind(newReceiver: Any) = new JavaTransformingMethodMirror(newReceiver, symbol, metadata)
      import metadata._

      def apply(args: Any*): Any = {
        val args1 = new Array[Any](args.length)
        var i = 0
        while (i < args1.length) {
          val arg = args(i)
          if (i >= paramCount) args1(i) = arg // don't transform varargs
          else if (isByName(i)) args1(i) = () => arg // don't transform by-name value class params
          else if (isDerivedValueClass(i)) args1(i) = paramUnboxers(i).invoke(arg)
          i += 1

    private class BytecodelessMethodMirror[T: ClassTag](val receiver: T, val symbol: MethodSymbol)
            extends MethodMirror {
      def bind(newReceiver: Any) = new BytecodelessMethodMirror(newReceiver.asInstanceOf[T], symbol)
      override def toString = s"bytecodeless method mirror for ${showDecl(symbol)} (bound to $receiver)"

      def apply(args: Any*): Any = {
        // checking type conformance is too much of a hassle, so we don't do it here
        // actually it's not even necessary, because we manually dispatch arguments below
        val params = symbol.paramss.flatten
        val perfectMatch = args.length == params.length
        // todo. this doesn't account for multiple vararg parameter lists
        // however those aren't supported by the mirror API:
        // hence I leave this code as is, to be fixed when the corresponding bug is fixed
        val varargMatch = args.length >= params.length - 1 && isVarArgsList(params)
        if (!perfectMatch && !varargMatch) {
          val n_arguments = if (isVarArgsList(params)) s"${params.length - 1} or more" else s"${params.length}"
          val s_arguments = if (params.length == 1 && !isVarArgsList(params)) "argument" else "arguments"
          abort(s"${showDecl(symbol)} takes $n_arguments $s_arguments")

        def objReceiver       = receiver.asInstanceOf[AnyRef]
        def objArg0           = args(0).asInstanceOf[AnyRef]
        def objArgs           = args.asInstanceOf[Seq[AnyRef]]
        def fail(msg: String) = abort(msg + ", it cannot be invoked with mirrors")

        def invokePrimitiveMethod = {
          val jmeths = classOf[BoxesRunTime].getDeclaredMethods.filter(_.getName == nme.primitiveMethodName(
          assert(jmeths.length == 1, jmeths.toList)
          val jmeth = jmeths.head
          val result = jmeth.invoke(null, (objReceiver +: objArgs).asInstanceOf[Seq[AnyRef]]: _*)
          if (jmeth.getReturnType == java.lang.Void.TYPE) ()
          else result

        symbol match {
          case Any_== | Object_==                     => ScalaRunTime.inlinedEquals(objReceiver, objArg0)
          case Any_!= | Object_!=                     => !ScalaRunTime.inlinedEquals(objReceiver, objArg0)
          case Any_## | Object_##                     => ScalaRunTime.hash(objReceiver)
          case Any_equals                             => receiver.equals(objArg0)
          case Any_hashCode                           => receiver.hashCode
          case Any_toString                           => receiver.toString
          case Object_eq                              => objReceiver eq objArg0
          case Object_ne                              => objReceiver ne objArg0
          case Object_synchronized                    => objReceiver.synchronized(objArg0)
          case sym if isGetClass(sym)                 => preciseClass(receiver)
          case Any_asInstanceOf                       => fail("Any.asInstanceOf requires a type argument")
          case Any_isInstanceOf                       => fail("Any.isInstanceOf requires a type argument")
          case Object_asInstanceOf                    => fail("AnyRef.%s is an internal method" format
          case Object_isInstanceOf                    => fail("AnyRef.%s is an internal method" format
          case Array_length                           => ScalaRunTime.array_length(objReceiver)
          case Array_apply                            => ScalaRunTime.array_apply(objReceiver, args(0).asInstanceOf[Int])
          case Array_update                           => ScalaRunTime.array_update(objReceiver, args(0).asInstanceOf[Int], args(1))
          case Array_clone                            => ScalaRunTime.array_clone(objReceiver)
          case sym if isStringConcat(sym)             => receiver.toString + objArg0
          case sym if sym.owner.isPrimitiveValueClass => invokePrimitiveMethod
          case sym if sym == Predef_classOf           => fail("Predef.classOf is a compile-time function")
          case sym if sym.isMacro                     => fail(s"${symbol.fullName} is a macro, i.e. a compile-time function")
          case _                                      => abort(s"unsupported symbol $symbol when invoking $this")

    private abstract class JavaTemplateMirror
            extends TemplateMirror {
      def outer: AnyRef
      def erasure: ClassSymbol

    private class JavaClassMirror(val outer: AnyRef, val symbol: ClassSymbol)
            extends JavaTemplateMirror with ClassMirror {
      def erasure = symbol
      def isStatic = false
      def reflectConstructor(constructor: MethodSymbol) = {
        checkConstructorOf(constructor, symbol)
        mkMethodMirror(outer, constructor)
      override def toString = s"class mirror for ${symbol.fullName} (bound to $outer)"

    private class JavaModuleMirror(val outer: AnyRef, val symbol: ModuleSymbol)
            extends JavaTemplateMirror with ModuleMirror {
      def erasure = symbol.moduleClass.asClass
      def isStatic = true
      def instance = {
        if (symbol.isTopLevel)
          staticSingletonInstance(classLoader, symbol.fullName)
          if (outer == null) staticSingletonInstance(classToJava(symbol.moduleClass.asClass))
          else innerSingletonInstance(outer,
      override def toString = s"module mirror for ${symbol.fullName} (bound to $outer)"

// -------------------- Java to Scala  -----------------------------------

    /** Does method `meth` erase to Java method `jmeth`?
     *  This is true if the Java method type is the same as the Scala method type after performing
     *  all Scala-specific transformations in InfoTransformers. (to be done)
    private def erasesTo(meth: Symbol, jmeth: jMethod): Boolean = {
      val mtpe = transformedType(meth)
      (mtpe.paramTypes map runtimeClass) == jmeth.getParameterTypes.toList &&
      runtimeClass(mtpe.resultType) == jmeth.getReturnType

    private def erasesTo(meth: Symbol, jconstr: jConstructor[_]): Boolean = {
      val mtpe = transformedType(meth)
      (mtpe.paramTypes map runtimeClass) == jconstr.getParameterTypes.toList &&
      runtimeClass(mtpe.resultType) == jconstr.getDeclaringClass

    def javaClass(path: String): jClass[_] =
      jClass.forName(path, true, classLoader)

    /** Does `path` correspond to a Java class with that fully qualified name in the current class loader? */
    def tryJavaClass(path: String): Option[jClass[_]] = (
      try Some(javaClass(path))
      catch { case ex @ (_: LinkageError | _: ClassNotFoundException) => None } // TODO - log

    /** The mirror that corresponds to the classloader that original defined the given Java class */
    def mirrorDefining(jclazz: jClass[_]): JavaMirror = {
      val cl = jclazz.getClassLoader
      if (cl == this.classLoader) this else runtimeMirror(cl)

    private object unpickler extends UnPickler {
      val symbolTable: thisUniverse.type = thisUniverse

    /** how connected????
     * Generate types for top-level Scala root class and root companion object
     *  from the pickled information stored in a corresponding Java class
     *  @param   clazz   The top-level Scala class for which info is unpickled
     *  @param   module  The top-level Scala companion object for which info is unpickled
     *  @param   jclazz  The Java class which contains the unpickled information in a
     *                   ScalaSignature or ScalaLongSignature annotation.
    def unpickleClass(clazz: Symbol, module: Symbol, jclazz: jClass[_]): Unit = {
      def markAbsent(tpe: Type) = setAllInfos(clazz, module, tpe)
      def handleError(ex: Exception) = {
        if (settings.debug) ex.printStackTrace()
        val msg = ex.getMessage()
          (if (msg eq null) "reflection error while loading " +
           else "error while loading " + + ", " + msg)
      // don't use classOf[scala.reflect.ScalaSignature] here, because it will use getClass.getClassLoader, not mirror's classLoader
      // don't use asInstanceOf either because of the same reason (lol, I cannot believe I fell for it)
      // don't use structural types to simplify reflective invocations because of the same reason
      def loadAnnotation(name: String): Option[java.lang.annotation.Annotation] =
        tryJavaClass(name) flatMap { annotClass =>
          val anns = jclazz.getAnnotations
          val result = anns find (_.annotationType == annotClass)
          if (result.isEmpty && (anns exists (_.annotationType.getName == name)))
            throw new ClassNotFoundException(
              sm"""Mirror classloader mismatch: $jclazz (loaded by ${})
                  |is unrelated to the mirror's classloader: (${})""")
      def loadBytes[T: ClassTag](name: String): Option[T] =
        loadAnnotation(name) map { ssig =>
          val bytesMethod = ssig.annotationType.getMethod("bytes")

      try {
        loadBytes[String]("scala.reflect.ScalaSignature") match {
          case Some(ssig) =>
            info(s"unpickling Scala $clazz and $module, owner = ${clazz.owner}")
            val bytes = ssig.getBytes
            val len = ByteCodecs.decode(bytes)
            assignAssociatedFile(clazz, module, jclazz)
            unpickler.unpickle(bytes take len, 0, clazz, module, jclazz.getName)
            markAllCompleted(clazz, module)
          case None =>
            loadBytes[Array[String]]("scala.reflect.ScalaLongSignature") match {
              case Some(slsig) =>
                info(s"unpickling Scala $clazz and $module with long Scala signature")
                val encoded = slsig flatMap (_.getBytes)
                val len = ByteCodecs.decode(encoded)
                val decoded = encoded.take(len)
                assignAssociatedFile(clazz, module, jclazz)
                unpickler.unpickle(decoded, 0, clazz, module, jclazz.getName)
                markAllCompleted(clazz, module)
              case None =>
                // class does not have a Scala signature; it's a Java class
                info("translating reflection info for Java " + jclazz) //debug
                initClassAndModule(clazz, module, new FromJavaClassCompleter(clazz, module, jclazz))
      } catch {
        case ex: MissingRequirementError =>
        case ex: IOException =>

    * A fresh Scala type parameter that corresponds to a Java type variable.
    *  The association between Scala type parameter and Java type variable is entered in the cache.
    *  @param   jtvar   The Java type variable
    private def createTypeParameter(jtvar: jTypeVariable[_ <: GenericDeclaration]): TypeSymbol = {
      val tparam = sOwner(jtvar).newTypeParameter(newTypeName(jtvar.getName))
        .setInfo(new TypeParamCompleter(jtvar))
      markFlagsCompleted(tparam)(mask = AllFlags)
      tparamCache enter (jtvar, tparam)

     * A completer that fills in the type of a Scala type parameter from the bounds of a Java type variable.
     *  @param   jtvar   The Java type variable
    private class TypeParamCompleter(jtvar: jTypeVariable[_ <: GenericDeclaration]) extends LazyType with FlagAgnosticCompleter {
      override def load(sym: Symbol) = complete(sym)
      override def complete(sym: Symbol) = {
        sym setInfo TypeBounds.upper(glb(jtvar.getBounds.toList map typeToScala map objToAny))

    private def assignAssociatedFile(clazz: Symbol, module: Symbol, jclazz: jClass[_]): Unit = {
      val associatedFile = ReflectionUtils.associatedFile(jclazz)
      clazz.associatedFile = associatedFile
      if (module != NoSymbol) module.associatedFile = associatedFile

     * Copy all annotations of Java annotated element `jann` over to Scala symbol `sym`.
     * Also creates `@throws` annotations if necessary.
     *  Pre: `sym` is already initialized with a concrete type.
     *  Note: If `sym` is a method or constructor, its parameter annotations are copied as well.
    private def copyAnnotations(sym: Symbol, jann: AnnotatedElement) {
      sym setAnnotations (jann.getAnnotations map JavaAnnotationProxy).toList
      // SI-7065: we're not using getGenericExceptionTypes here to be consistent with ClassfileParser
      val jexTpes = jann match {
        case jm: jMethod              => jm.getExceptionTypes.toList
        case jconstr: jConstructor[_] => jconstr.getExceptionTypes.toList
        case _                        => Nil
      jexTpes foreach (jexTpe => sym.addThrowsAnnotation(classSymbol(jexTpe)))

    private implicit class jClassOps(val clazz: jClass[_]) {
      def javaFlags: JavaAccFlags = JavaAccFlags(clazz)
      def scalaFlags: Long        = javaFlags.toScalaFlags
    private implicit class jMemberOps(val member: jMember) {
      def javaFlags: JavaAccFlags = JavaAccFlags(member)
      def scalaFlags: Long        = javaFlags.toScalaFlags

     * A completer that fills in the types of a Scala class and its companion object
     *  by copying corresponding type info from a Java class. This completer is used
     *  to reflect classes in Scala that do not have a Scala pickle info, be it
     *  because they are local classes or have been compiled from Java sources.
     *  @param   clazz   The Scala class for which info is copied
     *  @param   module  The Scala companion object for which info is copied
     *  @param   jclazz  The Java class
    private class FromJavaClassCompleter(clazz: Symbol, module: Symbol, jclazz: jClass[_]) extends LazyType with JavaClassCompleter with FlagAgnosticCompleter {
      // one doesn't need to do non-trivial computations to assign flags for Java-based reflection artifacts
      // therefore I'm moving flag-assigning logic from completion to construction
      val flags = jclazz.scalaFlags
      clazz setFlag (flags | JAVA)
      if (module != NoSymbol) {
        module setFlag (flags & PRIVATE | JAVA)
        module.moduleClass setFlag (flags & PRIVATE | JAVA)
      markFlagsCompleted(clazz, module)(mask = AllFlags)

      /** used to avoid cycles while initializing classes */
      private var parentsLevel = 0
      private var pendingLoadActions: List[() => Unit] = Nil
      private val relatedSymbols = clazz +: (if (module != NoSymbol) List(module, module.moduleClass) else Nil)

      override def load(sym: Symbol): Unit = {
        debugInfo("completing from Java " + sym + "/" + clazz.fullName)//debug
        assert(sym == clazz || (module != NoSymbol && (sym == module || sym == module.moduleClass)), sym)

        assignAssociatedFile(clazz, module, jclazz)
        propagatePackageBoundary(jclazz, relatedSymbols: _*)
        copyAnnotations(clazz, jclazz)
        // to do: annotations to set also for module?

        clazz setInfo new LazyPolyType(jclazz.getTypeParameters.toList map createTypeParameter)
        if (module != NoSymbol) {
          module setInfo module.moduleClass.tpe
          module.moduleClass setInfo new LazyPolyType(List())

      override def complete(sym: Symbol): Unit = {
        markAllCompleted(clazz, module)

      def completeRest(): Unit = gilSynchronized {
        val tparams = clazz.rawInfo.typeParams

        val parents = try {
          parentsLevel += 1
          val jsuperclazz = jclazz.getGenericSuperclass
          val ifaces = jclazz.getGenericInterfaces.toList map typeToScala
          val isAnnotation = JavaAccFlags(jclazz).isAnnotation
          if (isAnnotation) AnnotationClass.tpe :: ClassfileAnnotationClass.tpe :: ifaces
          else (if (jsuperclazz == null) AnyTpe else typeToScala(jsuperclazz)) :: ifaces
        } finally {
          parentsLevel -= 1
        clazz setInfo GenPolyType(tparams, new ClassInfoType(parents, newScope, clazz))
        if (module != NoSymbol) {
          module.moduleClass setInfo new ClassInfoType(List(), newScope, module.moduleClass)

        def enter(sym: Symbol, mods: JavaAccFlags) = followStatic(clazz, module, mods).info.decls enter sym

        def enterEmptyCtorIfNecessary(): Unit = {
          if (jclazz.getConstructors.isEmpty)

        for (jinner <- jclazz.getDeclaredClasses) {
          jclassAsScala(jinner) // inner class is entered as a side-effect
                                // no need to call enter explicitly

        pendingLoadActions ::= { () =>
          jclazz.getDeclaredFields  foreach (f => enter(jfieldAsScala(f),  f.javaFlags))
          jclazz.getDeclaredMethods foreach (m => enter(jmethodAsScala(m), m.javaFlags))
          jclazz.getConstructors    foreach (c => enter(jconstrAsScala(c), c.javaFlags))

        if (parentsLevel == 0) {
          while (pendingLoadActions.nonEmpty) {
            val item = pendingLoadActions.head
            pendingLoadActions = pendingLoadActions.tail

      class LazyPolyType(override val typeParams: List[Symbol]) extends LazyType with FlagAgnosticCompleter {
        override def complete(sym: Symbol) {
          markAllCompleted(clazz, module)

     * If Java modifiers `mods` contain STATIC, return the module class
     *  of the companion module of `clazz`, otherwise the class `clazz` itself.
    private def followStatic(clazz: Symbol, mods: JavaAccFlags): Symbol = followStatic(clazz, clazz.companionModule, mods)

    private def followStatic(clazz: Symbol, module: Symbol, mods: JavaAccFlags): Symbol =
      // SI-8196 `orElse(clazz)` needed for implementation details of the backend, such as the static
      //         field containing the cache for structural calls.
      if (mods.isStatic) module.moduleClass.orElse(clazz) else clazz

  /** Methods which need to be treated with care
   *  because they either are getSimpleName or call getSimpleName:
   *    public String getSimpleName()
   *    public boolean isAnonymousClass()
   *    public boolean isLocalClass()
   *    public String getCanonicalName()
   *  A typical manifestation:
   *    // java.lang.Error: sOwner(class Test$A$1) has failed
   *    // Caused by: java.lang.InternalError: Malformed class name
   *    //        at java.lang.Class.getSimpleName(
   *    //        at java.lang.Class.isAnonymousClass(
   *    //        at java.lang.Class.isLocalClass(
   *    // (see t5256c.scala for more details)
   *  TODO - find all such calls and wrap them.
   *  TODO - create mechanism to avoid the recurrence of unwrapped calls.
   implicit class RichClass(jclazz: jClass[_]) {
      // `jclazz.isLocalClass` doesn't work because of problems with `getSimpleName`
      // hence we have to approximate by removing the `isAnonymousClass` check
//      def isLocalClass0: Boolean = jclazz.isLocalClass
      def isLocalClass0: Boolean = jclazz.getEnclosingMethod != null || jclazz.getEnclosingConstructor != null

     * The Scala owner of the Scala class corresponding to the Java class `jclazz`
    // @eb: a weird classloader might return a null package for something with a non-empty package name
    // for example,
    // in that case we could invoke packageNameToScala(jPackageName) and, probably, be okay
    // however, I think, it's better to blow up, since weirdness of the class loader might bite us elsewhere
    // [martin] I think it's better to be forgiving here. Restoring packageNameToScala.
    private def sOwner(jclazz: jClass[_]): Symbol = jclazz match {
      case PrimitiveOrArray()            => ScalaPackageClass
      case EnclosedInMethod(jowner)      => methodToScala(jowner)
      case EnclosedInConstructor(jowner) => constructorToScala(jowner)
      case EnclosedInClass(jowner)       => followStatic(classToScala(jowner), jclazz.javaFlags)
      case EnclosedInPackage(jowner)     => packageToScala(jowner).moduleClass
      case _                             => packageNameToScala(jclazz.getName take jclazz.getName.lastIndexOf('.')).moduleClass

     * The Scala owner of the Scala symbol corresponding to the Java member `jmember`
    private def sOwner(jmember: jMember): Symbol = {
      followStatic(classToScala(jmember.getDeclaringClass), jmember.javaFlags)

     * The Scala owner of the Scala type parameter corresponding to the Java type variable `jtvar`
    private def sOwner(jtvar: jTypeVariable[_ <: GenericDeclaration]): Symbol =

     * Find declarations or definition in class `clazz` that maps to a Java
     *  entity with name `jname`. Because of name-mangling, this is more difficult
     *  than a simple name-based lookup via `decl`. If `decl` fails, members
     *  that start with the given name are searched instead.
    private def lookup(clazz: Symbol, jname: String): Symbol = {
      def approximateMatch(sym: Symbol, jstr: String): Boolean = (
           ( string_== jstr)
        || sym.isPrivate && (nme.expandedName(, sym.owner) string_== jstr)
      ) orElse {
        ( filter (approximateMatch(_, jname))).toList match {
          case List()    => NoSymbol
          case List(sym) => sym
          case alts      => clazz.newOverloaded(alts.head.tpe.prefix, alts)

     * The Scala method corresponding to given Java method.
     *  @param  jmeth  The Java method
     *  @return A Scala method object that corresponds to `jmeth`.
    def methodToScala(jmeth: jMethod): MethodSymbol =
      toScala(methodCache, jmeth)(_ methodToScala1 _)

    private def methodToScala1(jmeth: jMethod): MethodSymbol = {
      val jOwner = jmeth.getDeclaringClass
      val preOwner = classToScala(jOwner)
      val owner = followStatic(preOwner, jmeth.javaFlags)
      (lookup(owner, jmeth.getName) suchThat (erasesTo(_, jmeth)) orElse jmethodAsScala(jmeth))

     * The Scala constructor corresponding to given Java constructor.
     *  @param  jconstr  The Java constructor
     *  @return A Scala method object that corresponds to `jconstr`.
    def constructorToScala(jconstr: jConstructor[_]): MethodSymbol =
      toScala(constructorCache, jconstr)(_ constructorToScala1 _)

    private def constructorToScala1(jconstr: jConstructor[_]): MethodSymbol = {
      val owner = followStatic(classToScala(jconstr.getDeclaringClass), jconstr.javaFlags)
      (lookup(owner, jconstr.getName) suchThat (erasesTo(_, jconstr)) orElse jconstrAsScala(jconstr))

     * The Scala package corresponding to given Java package
    def packageToScala(jpkg: jPackage): ModuleSymbol = packageCache.toScala(jpkg) {

     * The Scala package with given fully qualified name.
    def packageNameToScala(fullname: String): ModuleSymbol = {
      if (fullname == "") EmptyPackage
      else {
        val jpkg = jPackage.getPackage(fullname)
        if (jpkg != null) packageToScala(jpkg) else makeScalaPackage(fullname)

     * The Scala package with given fully qualified name. Unlike `packageNameToScala`,
     *  this one bypasses the cache.
    private[JavaMirrors] def makeScalaPackage(fullname: String): ModuleSymbol = gilSynchronized {
      val split = fullname lastIndexOf '.'
      val ownerModule: ModuleSymbol =
        if (split > 0) packageNameToScala(fullname take split) else this.RootPackage
      val owner = ownerModule.moduleClass
      val name = (fullname: TermName) drop split + 1
      val opkg = decl name
      if (opkg.hasPackageFlag)
      else if (opkg == NoSymbol) {
        val pkg = owner.newPackage(name)
        pkg.moduleClass setInfo new LazyPackageType
        pkg setInfoAndEnter pkg.moduleClass.tpe
        markFlagsCompleted(pkg)(mask = AllFlags)
        info("made Scala "+pkg)
      } else
        throw new ReflectError(opkg+" is not a package")

    private def scalaSimpleName(jclazz: jClass[_]): TypeName = {
      val owner = sOwner(jclazz)
      val enclosingClass = jclazz.getEnclosingClass
      var prefix = if (enclosingClass != null) enclosingClass.getName else ""
      val isObject = owner.isModuleClass && !owner.isPackageClass
      if (isObject && !prefix.endsWith(nme.MODULE_SUFFIX_STRING)) prefix += nme.MODULE_SUFFIX_STRING
      var name = jclazz.getName.substring(prefix.length)
      name = name.substring(name.lastIndexOf(".") + 1)

     * The Scala class that corresponds to a given Java class.
     *  @param jclazz  The Java class
     *  @return A Scala class symbol that reflects all elements of the Java class,
     *          in the form they appear in the Scala pickling info, or, if that is
     *          not available, wrapped from the Java reflection info.
    def classToScala(jclazz: jClass[_]): ClassSymbol =
      toScala(classCache, jclazz)(_ classToScala1 _)

    private def classToScala1(jclazz: jClass[_]): ClassSymbol = {
      val jname = newTypeName(jclazz.getName)
      if (jname == fulltpnme.RuntimeNothing) NothingClass
      else if (jname == fulltpnme.RuntimeNull) NullClass
      else {
        val owner = sOwner(jclazz)
        val simpleName = scalaSimpleName(jclazz)

        def lookupClass = {
          def coreLookup(name: Name): Symbol =
   orElse {
              if (name.startsWith(nme.NAME_JOIN_STRING)) coreLookup(name drop 1) else NoSymbol
          if (nme.isModuleName(simpleName))
            coreLookup(nme.stripModuleSuffix(simpleName).toTermName) map (_.moduleClass)

        val cls =
          if (jclazz.isMemberClass && !nme.isImplClassName(jname))
          else if (jclazz.isLocalClass0 || scalacShouldntLoadClass(jname))
            // local classes and implementation classes not preserved by unpickling - treat as Java
            // upd. but only if they cannot be loaded as top-level classes
            // otherwise we may mistake mangled symbolic names for mangled nested names
            // in case when a Java binary name can be treated both as a top-level class and as a nested class
            // (as described in
            // we check for a top-level class first
            // this is totally correct, because a top-level class and a nested class with the same name cannot coexist
            // so it's either one or another, but not both - therefore we always load $-bearing classes correctly
            lookupClass orElse jclassAsScala(jclazz)
          else if (jclazz.isArray)
            javaTypeToValueClass(jclazz) orElse lookupClass

        assert (cls.isType,
          (if (cls != NoSymbol) s"not a type: symbol $cls" else "no symbol could be") +
          s" loaded from $jclazz in $owner with name $simpleName and classloader $classLoader")


     * The Scala type parameter that corresponds to a given Java type parameter.
     *  @param jparam  The Java type parameter
     *  @return A Scala type parameter symbol that has the same owner and name as the Java type parameter
    def typeParamToScala(jparam: jTypeVariable[_ <: GenericDeclaration]): TypeSymbol =
      toScala(tparamCache, jparam)(_ typeParamToScala1 _)

    private def typeParamToScala1(jparam: jTypeVariable[_ <: GenericDeclaration]): TypeSymbol = {
      val owner = genericDeclarationToScala(jparam.getGenericDeclaration) match {
        case PolyType(tparams, _) => tparams.find( string_== jparam.getName).get.asType

     * The Scala symbol that corresponds to a given Java generic declaration (class, method, or constructor)
    def genericDeclarationToScala(jdecl: GenericDeclaration): Symbol = jdecl match {
      case jclazz: jClass[_]        => classToScala(jclazz)
      case jmeth: jMethod           => methodToScala(jmeth)
      case jconstr: jConstructor[_] => constructorToScala(jconstr)
    def reflectMemberToScala(m: jMember): Symbol = m match {
      case x: GenericDeclaration => genericDeclarationToScala(x)
      case x: jField             => jfieldAsScala(x)

     * Given some Java type arguments, a corresponding list of Scala types, plus potentially
     *  some existentially bound type variables that represent wildcard arguments.
    private def targsToScala(owner: Symbol, args: List[jType]): (List[Type], List[TypeSymbol]) = {
      val tparams = new ListBuffer[TypeSymbol]
      def targToScala(arg: jType): Type = arg match {
        case jwild: WildcardType =>
          val tparam = owner.newExistential(newTypeName("T$" + tparams.length))
              lub(jwild.getLowerBounds.toList map typeToScala),
              glb(jwild.getUpperBounds.toList map typeToScala map objToAny)))
          tparams += tparam
          typeRef(NoPrefix, tparam, List())
        case _ =>
      (args map targToScala, tparams.toList)

     * The Scala type that corresponds to given Java type
    def typeToScala(jtpe: jType): Type = jtpe match {
      case jclazz: jClass[_] =>
        if (jclazz.isArray)
        else {
          val clazz = classToScala(jclazz)
          rawToExistential(typeRef(clazz.owner.thisType, clazz, List()))
      case japplied: ParameterizedType =>
        val sym = classToScala(japplied.getRawType.asInstanceOf[jClass[_]])
        val pre = sym.owner.thisType
        val args0 = japplied.getActualTypeArguments
        val (args, bounds) = targsToScala(pre.typeSymbol, args0.toList)
        newExistentialType(bounds, typeRef(pre, sym, args))
      case jarr: GenericArrayType =>
      case jtvar: jTypeVariable[_] =>
        val tparam = typeParamToScala(jtvar)
        typeRef(NoPrefix, tparam, List())

     * The Scala class that corresponds to given Java class without taking
     *  Scala pickling info into account.
     *  @param jclazz  The Java class
     *  @return A Scala class symbol that wraps all reflection info of `jclazz`
    private def jclassAsScala(jclazz: jClass[_]): ClassSymbol =
      toScala(classCache, jclazz)(_ jclassAsScala1 _)

    private def jclassAsScala1(jclazz: jClass[_]): ClassSymbol = {
      val owner = sOwner(jclazz)
      val name = scalaSimpleName(jclazz)
      val completer = (clazz: Symbol, module: Symbol) => new FromJavaClassCompleter(clazz, module, jclazz)

      initAndEnterClassAndModule(owner, name, completer)._1

     * The Scala field that corresponds to given Java field without taking
     *  Scala pickling info into account.
     *  @param jfield  The Java field
     *  @return A Scala value symbol that wraps all reflection info of `jfield`
    private def jfieldAsScala(jfield: jField): TermSymbol =
      toScala(fieldCache, jfield)(_ jfieldAsScala1 _)

    private def jfieldAsScala1(jfield: jField): TermSymbol = {
      val field = sOwner(jfield)
          .newValue(newTermName(jfield.getName), NoPosition, jfield.scalaFlags)

      fieldCache.enter(jfield, field)
      propagatePackageBoundary(jfield, field)
      copyAnnotations(field, jfield)

    private def setMethType(meth: Symbol, tparams: List[Symbol], paramtpes: List[Type], restpe: Type) = {
      meth setInfo GenPolyType(tparams, MethodType(meth.owner.newSyntheticValueParams(paramtpes map objToAny), restpe))

     * The Scala method that corresponds to given Java method without taking
     *  Scala pickling info into account.
     *  @param jmeth  The Java method
     *  @return A Scala method symbol that wraps all reflection info of `jmethod`
    private def jmethodAsScala(jmeth: jMethod): MethodSymbol =
      toScala(methodCache, jmeth)(_ jmethodAsScala1 _)

    private def jmethodAsScala1(jmeth: jMethod): MethodSymbol = {
      val clazz = sOwner(jmeth)
      val meth = clazz.newMethod(newTermName(jmeth.getName), NoPosition, jmeth.scalaFlags)
      methodCache enter (jmeth, meth)
      val tparams = jmeth.getTypeParameters.toList map createTypeParameter
      val paramtpes = jmeth.getGenericParameterTypes.toList map typeToScala
      val resulttpe = typeToScala(jmeth.getGenericReturnType)
      setMethType(meth, tparams, paramtpes, resulttpe)
      propagatePackageBoundary(jmeth.javaFlags, meth)
      copyAnnotations(meth, jmeth)
      if (jmeth.javaFlags.isVarargs) meth modifyInfo arrayToRepeated

     * The Scala constructor that corresponds to given Java constructor without taking
     *  Scala pickling info into account.
     *  @param jconstr  The Java constructor
     *  @return A Scala constructor symbol that wraps all reflection info of `jconstr`
    private def jconstrAsScala(jconstr: jConstructor[_]): MethodSymbol =
      toScala(constructorCache, jconstr)(_ jconstrAsScala1 _)

    private def jconstrAsScala1(jconstr: jConstructor[_]): MethodSymbol = {
      // [Martin] Note: I know there's a lot of duplication wrt jmethodAsScala, but don't think it's worth it to factor this out.
      val clazz = sOwner(jconstr)
      val constr = clazz.newConstructor(NoPosition, jconstr.scalaFlags)
      constructorCache enter (jconstr, constr)
      val tparams = jconstr.getTypeParameters.toList map createTypeParameter
      val paramtpes = jconstr.getGenericParameterTypes.toList map typeToScala
      setMethType(constr, tparams, paramtpes, clazz.tpe_*)
      constr setInfo GenPolyType(tparams, MethodType(clazz.newSyntheticValueParams(paramtpes), clazz.tpe))
      propagatePackageBoundary(jconstr.javaFlags, constr)
      copyAnnotations(constr, jconstr)

// -------------------- Scala to Java  -----------------------------------

    /** The Java class corresponding to given Scala class.
     *  Note: This only works for
     *   - top-level classes
     *   - Scala classes that were generated via jclassToScala
     *   - classes that have a class owner that has a corresponding Java class
     *  @throws A `ClassNotFoundException` for all Scala classes not in one of these categories.
    def classToJava(clazz: ClassSymbol): jClass[_] = classCache.toJava(clazz) {
      def noClass = throw new ClassNotFoundException("no Java class corresponding to "+clazz+" found")
      //println("classToJava "+clazz+" "+clazz.owner+" "+clazz.owner.isPackageClass)//debug
      if (clazz.isPrimitiveValueClass)
      else if (clazz == ArrayClass)
      else if (clazz.isTopLevel)
      else if (clazz.owner.isClass) {
        val childOfClass          = !clazz.owner.isModuleClass
        val childOfTopLevel       = clazz.owner.isTopLevel
        val childOfTopLevelObject = clazz.owner.isModuleClass && childOfTopLevel

        // suggested in
        var ownerClazz = classToJava(clazz.owner.asClass)
        if (childOfTopLevelObject)
          ownerClazz = jClass.forName(ownerClazz.getName stripSuffix "$", true, ownerClazz.getClassLoader)

        val ownerChildren = ownerClazz.getDeclaredClasses

        var fullNameOfJavaClass = ownerClazz.getName
        if (childOfClass || childOfTopLevel) fullNameOfJavaClass += "$"
        fullNameOfJavaClass +=

        // compactify (see SI-7779)
        fullNameOfJavaClass = fullNameOfJavaClass match {
          case PackageAndClassPattern(pack, clazzName) =>
            // in a package
            pack + compactifyName(clazzName)
          case _ =>
            // in the empty package

        if (clazz.isModuleClass) fullNameOfJavaClass += "$"

        // println(s"ownerChildren = ${ownerChildren.toList}")
        // println(s"fullNameOfJavaClass = $fullNameOfJavaClass")
        ownerChildren.find(_.getName == fullNameOfJavaClass).getOrElse(noClass)
      } else

    private val PackageAndClassPattern = """(.*\.)(.*)$""".r

    private def expandedName(sym: Symbol): String =
      if (sym.isPrivate) nme.expandedName(, sym.owner).toString

    /** The Java field corresponding to a given Scala field.
     *  @param   fld The Scala field.
    def fieldToJava(fld: TermSymbol): jField = fieldCache.toJava(fld) {
      val jclazz = classToJava(fld.owner.asClass)
      val jname =
      try jclazz getDeclaredField jname
      catch {
        case ex: NoSuchFieldException => jclazz getDeclaredField expandedName(fld)

    /** The Java method corresponding to a given Scala method.
     *  @param   meth The Scala method
    def methodToJava(meth: MethodSymbol): jMethod = methodCache.toJava(meth) {
      val jclazz = classToJava(meth.owner.asClass)
      val paramClasses = transformedType(meth).paramTypes map typeToJavaClass
      val jname =
      try jclazz getDeclaredMethod (jname, paramClasses: _*)
      catch {
        case ex: NoSuchMethodException =>
          jclazz getDeclaredMethod (expandedName(meth), paramClasses: _*)

    /** The Java constructor corresponding to a given Scala constructor.
     *  @param   constr The Scala constructor
    def constructorToJava(constr: MethodSymbol): jConstructor[_] = constructorCache.toJava(constr) {
      val jclazz = classToJava(constr.owner.asClass)
      val paramClasses = transformedType(constr).paramTypes map typeToJavaClass
      val effectiveParamClasses =
        if (!constr.owner.owner.isStaticOwner) jclazz.getEnclosingClass +: paramClasses
        else paramClasses
      jclazz getDeclaredConstructor (effectiveParamClasses: _*)

    private def jArrayClass(elemClazz: jClass[_]): jClass[_] = {
      jArray.newInstance(elemClazz, 0).getClass

    /** The Java class that corresponds to given Scala type.
     *  Pre: Scala type is already transformed to Java level.
    def typeToJavaClass(tpe: Type): jClass[_] = tpe match {
      case ExistentialType(_, rtpe)                  => typeToJavaClass(rtpe)
      case TypeRef(_, ArrayClass, List(elemtpe))     => jArrayClass(typeToJavaClass(elemtpe))
      case TypeRef(_, sym: ClassSymbol, _)           => classToJava(sym.asClass)
      case tpe @ TypeRef(_, sym: AliasTypeSymbol, _) => typeToJavaClass(tpe.dealias)
      case SingleType(_, sym: ModuleSymbol)          => classToJava(sym.moduleClass.asClass)
      case _                                         => throw new NoClassDefFoundError("no Java class corresponding to "+tpe+" found")

  /** Assert that packages have package scopes */
  override def validateClassInfo(tp: ClassInfoType) {
    assert(!tp.typeSymbol.isPackageClass || tp.decls.isInstanceOf[PackageScope])

  override def newPackageScope(pkgClass: Symbol) = new PackageScope(pkgClass)

  override def scopeTransform(owner: Symbol)(op: => Scope): Scope =
    if (owner.isPackageClass) else op

  override def mirrorThatLoaded(sym: Symbol): Mirror = sym.enclosingRootClass match {
    case root: RootSymbol => root.mirror
    case _ => abort(s"${sym}.enclosingRootClass = ${sym.enclosingRootClass}, which is not a RootSymbol")

  /** 1. If `owner` is a package class (but not the empty package) and `name` is a term name, make a new package
   *  <owner>.<name>, otherwise return NoSymbol.
   *  Exception: If owner is root and a java class with given name exists, create symbol in empty package instead
   *  2. If `owner` is the scala package and `name` designates a phantom class, return
   *     the corresponding class symbol and enter it into this mirror's ScalaPackage.
  override def missingHook(owner: Symbol, name: Name): Symbol = {
    if (owner.hasPackageFlag) {
      val mirror = mirrorThatLoaded(owner)
      if (owner.isRootSymbol && mirror.tryJavaClass(name.toString).isDefined)
        return decl name
      if (name.isTermName && !owner.isEmptyPackageClass)
        return mirror.makeScalaPackage(
          if (owner.isRootSymbol) name.toString else owner.fullName+"."+name)
      if (name == tpnme.AnyRef && owner.owner.isRoot && == tpnme.scala_)
        // when we synthesize the scala.AnyRef symbol, we need to add it to the scope of the scala package
        // the problem is that adding to the scope implies doing something like ` enter anyRef`
        // which entails running a completer for the scala package
        // which will try to unpickle the stuff in scala/package.class
        // which will transitively load scala.AnyRef
        // which doesn't exist yet, because it hasn't been added to the scope yet
        // this missing hook ties the knot without introducing synchronization problems like before
        return definitions.AnyRefClass
    info("*** missing: "+name+"/"+name.isTermName+"/"+owner+"/"+owner.hasPackageFlag+"/"
    super.missingHook(owner, name)

private[reflect] class ReflectError(msg: String) extends java.lang.Error(msg)

private[reflect] class HasJavaClass[J](val getClazz: J => java.lang.Class[_])

Other Scala source code examples

Here is a short list of links related to this Scala JavaMirrors.scala source code file:

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