使用Scala Mongo驱动程序序列化为对象？

Question

我是scala mongo驱动程序的新手，正在尝试了解如何从Document映射类？该文档似乎都没有显示如何完成此操作。在.net驱动程序中，它就像传递通用类并自动映射字段一样容易。Scala中没有类似的东西吗？

Answer 1

他们并不容易。通过java挖掘，我想出了这个解决方案：

import org.bson.codecs.DecoderContext
import org.bson.codecs.configuration.CodecRegistries.{fromProviders, fromRegistries}
import org.bson.codecs.configuration.CodecRegistry
import org.bson.{BsonDocumentReader, BsonDocumentWrapper}
import org.mongodb.scala.bson.codecs.{DEFAULT_CODEC_REGISTRY, Macros}
import org.mongodb.scala.bson.collection.mutable.Document

import scala.reflect.classTag

case class Person(firstName: String, lastName: String)

object MongoTest extends App {

  val personCodecProvider = Macros.createCodecProvider[Person]()
  val codecRegistry: CodecRegistry = fromRegistries(fromProviders(personCodecProvider), DEFAULT_CODEC_REGISTRY)

  val document = Document("firstName" -> "first", "lastName" -> "last")
  val bsonDocument = BsonDocumentWrapper.asBsonDocument(document, DEFAULT_CODEC_REGISTRY)

  val bsonReader = new BsonDocumentReader(bsonDocument)
  val decoderContext = DecoderContext.builder.build
  val codec = codecRegistry.get(classTag[Person].runtimeClass)
  val person: Person = codec.decode(bsonReader, decoderContext).asInstanceOf[Person]

  println(s"person: $person")
}