scala - Scala 代码生成类型不匹配 (ScalaPB)

Question

我有一个 protobuf 文件...
我使用 ScalaPB 将其转换为 Scala 文件。这样我就可以...
在我的 Juypter notebook* 中使用它进行转换。可悲的是，当我...
运行特定的单元格我得到一个类型不匹配的错误，我不知道为什么？

由于 protobuf 文件与 Python 一起使用并生成了 Scala 代码，所以这里有什么不妥之处？这可能是一个错误吗？

*笔记本com.google.protobuf:protobuf-java:3.5.0,com.thesamet.scalapb:sparksql-scalapb_2.11:0.7.0用作进口

来源和错误

protobuf 文件：

syntax = "proto2";

import "scalapb/scalapb.proto";

option (scalapb.options) = {
  flat_package: true
  single_file: true
};

message JSONEntry {
  required uint64 ts = 1;
  required string data = 2;
}

message JSONOutput {
  optional string metadata = 1;
  repeated JSONEntry entry = 2;
}

Scala（生成）代码

// Generated by the Scala Plugin for the Protocol Buffer Compiler.
// Do not edit!
//
// Protofile syntax: PROTO2


@SerialVersionUID(0L)
final case class JSONEntry(
    ts: _root_.scala.Long,
    data: _root_.scala.Predef.String
    ) extends scalapb.GeneratedMessage with scalapb.Message[JSONEntry] with scalapb.lenses.Updatable[JSONEntry] {
    @transient
    private[this] var __serializedSizeCachedValue: _root_.scala.Int = 0
    private[this] def __computeSerializedValue(): _root_.scala.Int = {
      var __size = 0
      __size += _root_.com.google.protobuf.CodedOutputStream.computeUInt64Size(1, ts)
      __size += _root_.com.google.protobuf.CodedOutputStream.computeStringSize(2, data)
      __size
    }
    final override def serializedSize: _root_.scala.Int = {
      var read = __serializedSizeCachedValue
      if (read == 0) {
        read = __computeSerializedValue()
        __serializedSizeCachedValue = read
      }
      read
    }
    def writeTo(`_output__`: _root_.com.google.protobuf.CodedOutputStream): Unit = {
      _output__.writeUInt64(1, ts)
      _output__.writeString(2, data)
    }
    def mergeFrom(`_input__`: _root_.com.google.protobuf.CodedInputStream): JSONEntry = {
      var __ts = this.ts
      var __data = this.data
      var __requiredFields0: _root_.scala.Long = 0x3L
      var _done__ = false
      while (!_done__) {
        val _tag__ = _input__.readTag()
        _tag__ match {
          case 0 => _done__ = true
          case 8 =>
            __ts = _input__.readUInt64()
            __requiredFields0 &= 0xfffffffffffffffeL
          case 18 =>
            __data = _input__.readString()
            __requiredFields0 &= 0xfffffffffffffffdL
          case tag => _input__.skipField(tag)
        }
      }
      if (__requiredFields0 != 0L) { throw new _root_.com.google.protobuf.InvalidProtocolBufferException("Message missing required fields.") } 
      JSONEntry(
          ts = __ts,
          data = __data
      )
    }
    def withTs(__v: _root_.scala.Long): JSONEntry = copy(ts = __v)
    def withData(__v: _root_.scala.Predef.String): JSONEntry = copy(data = __v)
    def getFieldByNumber(__fieldNumber: _root_.scala.Int): scala.Any = {
      (__fieldNumber: @_root_.scala.unchecked) match {
        case 1 => ts
        case 2 => data
      }
    }
    def getField(__field: _root_.scalapb.descriptors.FieldDescriptor): _root_.scalapb.descriptors.PValue = {
      require(__field.containingMessage eq companion.scalaDescriptor)
      (__field.number: @_root_.scala.unchecked) match {
        case 1 => _root_.scalapb.descriptors.PLong(ts)
        case 2 => _root_.scalapb.descriptors.PString(data)
      }
    }
    def toProtoString: _root_.scala.Predef.String = _root_.scalapb.TextFormat.printToUnicodeString(this)
    def companion = JSONEntry
}

object JSONEntry extends scalapb.GeneratedMessageCompanion[JSONEntry] {
  implicit def messageCompanion: scalapb.GeneratedMessageCompanion[JSONEntry] = this
  def fromFieldsMap(__fieldsMap: scala.collection.immutable.Map[_root_.com.google.protobuf.Descriptors.FieldDescriptor, scala.Any]): JSONEntry = {
    require(__fieldsMap.keys.forall(_.getContainingType() == javaDescriptor), "FieldDescriptor does not match message type.")
    val __fields = javaDescriptor.getFields
    JSONEntry(
      __fieldsMap(__fields.get(0)).asInstanceOf[_root_.scala.Long],
      __fieldsMap(__fields.get(1)).asInstanceOf[_root_.scala.Predef.String]
    )
  }
  implicit def messageReads: _root_.scalapb.descriptors.Reads[JSONEntry] = _root_.scalapb.descriptors.Reads{
    case _root_.scalapb.descriptors.PMessage(__fieldsMap) =>
      require(__fieldsMap.keys.forall(_.containingMessage == scalaDescriptor), "FieldDescriptor does not match message type.")
      JSONEntry(
        __fieldsMap.get(scalaDescriptor.findFieldByNumber(1).get).get.as[_root_.scala.Long],
        __fieldsMap.get(scalaDescriptor.findFieldByNumber(2).get).get.as[_root_.scala.Predef.String]
      )
    case _ => throw new RuntimeException("Expected PMessage")
  }
  def javaDescriptor: _root_.com.google.protobuf.Descriptors.Descriptor = DataProto.javaDescriptor.getMessageTypes.get(0)
  def scalaDescriptor: _root_.scalapb.descriptors.Descriptor = DataProto.scalaDescriptor.messages(0)
  def messageCompanionForFieldNumber(__number: _root_.scala.Int): _root_.scalapb.GeneratedMessageCompanion[_] = throw new MatchError(__number)
  lazy val nestedMessagesCompanions: Seq[_root_.scalapb.GeneratedMessageCompanion[_]] = Seq.empty
  def enumCompanionForFieldNumber(__fieldNumber: _root_.scala.Int): _root_.scalapb.GeneratedEnumCompanion[_] = throw new MatchError(__fieldNumber)
  lazy val defaultInstance = JSONEntry(
    ts = 0L,
    data = ""
  )
  implicit class JSONEntryLens[UpperPB](_l: _root_.scalapb.lenses.Lens[UpperPB, JSONEntry]) extends _root_.scalapb.lenses.ObjectLens[UpperPB, JSONEntry](_l) {
    def ts: _root_.scalapb.lenses.Lens[UpperPB, _root_.scala.Long] = field(_.ts)((c_, f_) => c_.copy(ts = f_))
    def data: _root_.scalapb.lenses.Lens[UpperPB, _root_.scala.Predef.String] = field(_.data)((c_, f_) => c_.copy(data = f_))
  }
  final val TS_FIELD_NUMBER = 1
  final val DATA_FIELD_NUMBER = 2
}

@SerialVersionUID(0L)
final case class JSONOutput(
    metadata: scala.Option[_root_.scala.Predef.String] = None,
    entry: _root_.scala.collection.Seq[JSONEntry] = _root_.scala.collection.Seq.empty
    ) extends scalapb.GeneratedMessage with scalapb.Message[JSONOutput] with scalapb.lenses.Updatable[JSONOutput] {
    @transient
    private[this] var __serializedSizeCachedValue: _root_.scala.Int = 0
    private[this] def __computeSerializedValue(): _root_.scala.Int = {
      var __size = 0
      if (metadata.isDefined) { __size += _root_.com.google.protobuf.CodedOutputStream.computeStringSize(1, metadata.get) }
      entry.foreach(entry => __size += 1 + _root_.com.google.protobuf.CodedOutputStream.computeUInt32SizeNoTag(entry.serializedSize) + entry.serializedSize)
      __size
    }
    final override def serializedSize: _root_.scala.Int = {
      var read = __serializedSizeCachedValue
      if (read == 0) {
        read = __computeSerializedValue()
        __serializedSizeCachedValue = read
      }
      read
    }
    def writeTo(`_output__`: _root_.com.google.protobuf.CodedOutputStream): Unit = {
      metadata.foreach { __v =>
        _output__.writeString(1, __v)
      };
      entry.foreach { __v =>
        _output__.writeTag(2, 2)
        _output__.writeUInt32NoTag(__v.serializedSize)
        __v.writeTo(_output__)
      };
    }
    def mergeFrom(`_input__`: _root_.com.google.protobuf.CodedInputStream): JSONOutput = {
      var __metadata = this.metadata
      val __entry = (_root_.scala.collection.immutable.Vector.newBuilder[JSONEntry] ++= this.entry)
      var _done__ = false
      while (!_done__) {
        val _tag__ = _input__.readTag()
        _tag__ match {
          case 0 => _done__ = true
          case 10 =>
            __metadata = Option(_input__.readString())
          case 18 =>
            __entry += _root_.scalapb.LiteParser.readMessage(_input__, JSONEntry.defaultInstance)
          case tag => _input__.skipField(tag)
        }
      }
      JSONOutput(
          metadata = __metadata,
          entry = __entry.result()
      )
    }
    def getMetadata: _root_.scala.Predef.String = metadata.getOrElse("")
    def clearMetadata: JSONOutput = copy(metadata = None)
    def withMetadata(__v: _root_.scala.Predef.String): JSONOutput = copy(metadata = Option(__v))
    def clearEntry = copy(entry = _root_.scala.collection.Seq.empty)
    def addEntry(__vs: JSONEntry*): JSONOutput = addAllEntry(__vs)
    def addAllEntry(__vs: TraversableOnce[JSONEntry]): JSONOutput = copy(entry = entry ++ __vs)
    def withEntry(__v: _root_.scala.collection.Seq[JSONEntry]): JSONOutput = copy(entry = __v)
    def getFieldByNumber(__fieldNumber: _root_.scala.Int): scala.Any = {
      (__fieldNumber: @_root_.scala.unchecked) match {
        case 1 => metadata.orNull
        case 2 => entry
      }
    }
    def getField(__field: _root_.scalapb.descriptors.FieldDescriptor): _root_.scalapb.descriptors.PValue = {
      require(__field.containingMessage eq companion.scalaDescriptor)
      (__field.number: @_root_.scala.unchecked) match {
        case 1 => metadata.map(_root_.scalapb.descriptors.PString).getOrElse(_root_.scalapb.descriptors.PEmpty)
        case 2 => _root_.scalapb.descriptors.PRepeated(entry.map(_.toPMessage)(_root_.scala.collection.breakOut))
      }
    }
    def toProtoString: _root_.scala.Predef.String = _root_.scalapb.TextFormat.printToUnicodeString(this)
    def companion = JSONOutput
}

object JSONOutput extends scalapb.GeneratedMessageCompanion[JSONOutput] {
  implicit def messageCompanion: scalapb.GeneratedMessageCompanion[JSONOutput] = this
  def fromFieldsMap(__fieldsMap: scala.collection.immutable.Map[_root_.com.google.protobuf.Descriptors.FieldDescriptor, scala.Any]): JSONOutput = {
    require(__fieldsMap.keys.forall(_.getContainingType() == javaDescriptor), "FieldDescriptor does not match message type.")
    val __fields = javaDescriptor.getFields
    JSONOutput(
      __fieldsMap.get(__fields.get(0)).asInstanceOf[scala.Option[_root_.scala.Predef.String]],
      __fieldsMap.getOrElse(__fields.get(1), Nil).asInstanceOf[_root_.scala.collection.Seq[JSONEntry]]
    )
  }
  implicit def messageReads: _root_.scalapb.descriptors.Reads[JSONOutput] = _root_.scalapb.descriptors.Reads{
    case _root_.scalapb.descriptors.PMessage(__fieldsMap) =>
      require(__fieldsMap.keys.forall(_.containingMessage == scalaDescriptor), "FieldDescriptor does not match message type.")
      JSONOutput(
        __fieldsMap.get(scalaDescriptor.findFieldByNumber(1).get).flatMap(_.as[scala.Option[_root_.scala.Predef.String]]),
        __fieldsMap.get(scalaDescriptor.findFieldByNumber(2).get).map(_.as[_root_.scala.collection.Seq[JSONEntry]]).getOrElse(_root_.scala.collection.Seq.empty)
      )
    case _ => throw new RuntimeException("Expected PMessage")
  }
  def javaDescriptor: _root_.com.google.protobuf.Descriptors.Descriptor = DataProto.javaDescriptor.getMessageTypes.get(1)
  def scalaDescriptor: _root_.scalapb.descriptors.Descriptor = DataProto.scalaDescriptor.messages(1)
  def messageCompanionForFieldNumber(__number: _root_.scala.Int): _root_.scalapb.GeneratedMessageCompanion[_] = {
    var __out: _root_.scalapb.GeneratedMessageCompanion[_] = null
    (__number: @_root_.scala.unchecked) match {
      case 2 => __out = JSONEntry
    }
    __out
  }
  lazy val nestedMessagesCompanions: Seq[_root_.scalapb.GeneratedMessageCompanion[_]] = Seq.empty
  def enumCompanionForFieldNumber(__fieldNumber: _root_.scala.Int): _root_.scalapb.GeneratedEnumCompanion[_] = throw new MatchError(__fieldNumber)
  lazy val defaultInstance = JSONOutput(
  )
  implicit class JSONOutputLens[UpperPB](_l: _root_.scalapb.lenses.Lens[UpperPB, JSONOutput]) extends _root_.scalapb.lenses.ObjectLens[UpperPB, JSONOutput](_l) {
    def metadata: _root_.scalapb.lenses.Lens[UpperPB, _root_.scala.Predef.String] = field(_.getMetadata)((c_, f_) => c_.copy(metadata = Option(f_)))
    def optionalMetadata: _root_.scalapb.lenses.Lens[UpperPB, scala.Option[_root_.scala.Predef.String]] = field(_.metadata)((c_, f_) => c_.copy(metadata = f_))
    def entry: _root_.scalapb.lenses.Lens[UpperPB, _root_.scala.collection.Seq[JSONEntry]] = field(_.entry)((c_, f_) => c_.copy(entry = f_))
  }
  final val METADATA_FIELD_NUMBER = 1
  final val ENTRY_FIELD_NUMBER = 2
}

object DataProto extends _root_.scalapb.GeneratedFileObject {
  lazy val dependencies: Seq[_root_.scalapb.GeneratedFileObject] = Seq(
    scalapb.options.ScalapbProto
  )
  lazy val messagesCompanions: Seq[_root_.scalapb.GeneratedMessageCompanion[_]] = Seq(
    JSONEntry,
    JSONOutput
  )
  private lazy val ProtoBytes: Array[Byte] =
      scalapb.Encoding.fromBase64(scala.collection.Seq(
  """CgpkYXRhLnByb3RvGhVzY2FsYXBiL3NjYWxhcGIucHJvdG8iLwoJSlNPTkVudHJ5Eg4KAnRzGAEgAigEUgJ0cxISCgRkYXRhG
  AIgAigJUgRkYXRhIkoKCkpTT05PdXRwdXQSGgoIbWV0YWRhdGEYASABKAlSCG1ldGFkYXRhEiAKBWVudHJ5GAIgAygLMgouSlNPT
  kVudHJ5UgVlbnRyeUIH4j8EEAEoAQ=="""
      ).mkString)
  lazy val scalaDescriptor: _root_.scalapb.descriptors.FileDescriptor = {
    val scalaProto = com.google.protobuf.descriptor.FileDescriptorProto.parseFrom(ProtoBytes)
    _root_.scalapb.descriptors.FileDescriptor.buildFrom(scalaProto, dependencies.map(_.scalaDescriptor))
  }
  lazy val javaDescriptor: com.google.protobuf.Descriptors.FileDescriptor = {
    val javaProto = com.google.protobuf.DescriptorProtos.FileDescriptorProto.parseFrom(ProtoBytes)
    com.google.protobuf.Descriptors.FileDescriptor.buildFrom(javaProto, Array(
      scalapb.options.ScalapbProto.javaDescriptor
    ))
  }
  @deprecated("Use javaDescriptor instead. In a future version this will refer to scalaDescriptor.", "ScalaPB 0.5.47")
  def descriptor: com.google.protobuf.Descriptors.FileDescriptor = javaDescriptor
}

错误

<console>:82: error: type mismatch;
 found   : JSONEntry.type
 required: scalapb.GeneratedMessageCompanion[_]
           def companion = JSONEntry
                           ^

score 3 · Accepted Answer

我能够使用以下代码成功编译您的原型文件

项目/scalapb.sbt

addSbtPlugin("com.thesamet" % "sbt-protoc" % "0.99.16")
libraryDependencies += "com.thesamet.scalapb" %% "compilerplugin" % "0.7.0"

构建.sbt

lazy val root = (project in file(".")).
  settings(
    inThisBuild(List(
      organization := "com.example",
      scalaVersion := "2.12.4",
      version      := "0.1.0-SNAPSHOT"
    )),
    name := "protobuf",
    libraryDependencies ++= Seq(
      "com.thesamet.scalapb" %% "scalapb-runtime" % scalapb.compiler.Version.scalapbVersion % "protobuf"
     ),
    PB.targets in (Compile) := Seq(
      scalapb.gen() -> (sourceManaged in Compile).value
    )
 )

现在，如果您将照片文件复制并粘贴到src/main/protobufashello.proto并执行sbt clean compile

唯一不同的是我在照片文件中添加了一个包

syntax = "proto2";

import "scalapb/scalapb.proto";

option (scalapb.options) = {
  package_name: "com.abhi"
  flat_package: true
  single_file: true
};

message JSONEntry {
  required uint64 ts = 1;
  required string data = 2;
}

message JSONOutput {
  optional string metadata = 1;
  repeated JSONEntry entry = 2;
}

现在终于在你的应用程序中使用生成的代码

包示例 import com.abhi.JSONEntry import java.io._

object Hello extends App {
  val jsonEntry = JSONEntry(10L, "foo")
  val target = new FileOutputStream(new File("foo.bin"))
  jsonEntry.writeTo(target)
  target.close()
}

代码编译正确，没有编译错误

scala - Scala 代码生成类型不匹配 (ScalaPB)

来源和错误

protobuf 文件：

Scala（生成）代码

错误

1 回答 1

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