我是
scala mongo驱动程序的新手,我正在尝试了解如何从Document中映射类?这些文档似乎都没有显示这是如何完成的.在.net驱动程序中,它就像传递泛型并具有自动映射的字段一样简单. scala中没有类似的东西吗? 最佳答案 它们并不容易.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")
}