java - 如何从 Scala 中的泛型类型获取字段名称和字段类型？

Question

在 Scala 中，给定泛型类型 T，如何检索字段名称列表和字段类型？例如，如果我有案例类:

case class Person(name: String, age: Int, gender: Boolean)

通用函数:

def getFieldNamesAndTypes[T](): Seq[(String, String)]

我希望能够检索字段(名称、类型)的序列(以便字段出现):

val fieldNamesAndTypes = getFieldNamesAndTypes[Person]()

Answer 1

看来你需要反射API:

Welcome to Scala 2.13.1 (OpenJDK 64-Bit Server VM, Java 1.8.0_222).
Type in expressions for evaluation. Or try :help.

scala> import scala.reflect.runtime.universe._
import scala.reflect.runtime.universe._

scala> def getFields[T: TypeTag] = typeOf[T].members.collect {
     |   case m: MethodSymbol if m.isCaseAccessor => (m.name.toString, m.returnType.toString)
     | }
getFields: [T](implicit evidence$1: reflect.runtime.universe.TypeTag[T])Iterable[(String, String)]

scala> case class Person(name: String, age: Int, gender: Boolean)
defined class Person

scala> getFields[Person]
res0: Iterable[(String, String)] = List((gender,Boolean), (age,Int), (name,String))