Question

如何在Scala 2.10.x中按名称动态查找对象属性的值？

E.g。鉴于课程（它不能成为案例类）：

class Row(val click: Boolean,
          val date: String,
          val time: String)

我想做类似的事情：

val fields = List("click", "date", "time")
val row = new Row(click=true, date="2015-01-01", time="12:00:00")
fields.foreach(f => println(row.getProperty(f)))    // how to do this?

Answer 1

class Row(val click: Boolean,
      val date: String,
      val time: String)

val row = new Row(click=true, date="2015-01-01", time="12:00:00")

row.getClass.getDeclaredFields foreach { f =>
 f.setAccessible(true)
 println(f.getName)
 println(f.get(row))
}

Answer 2

您还可以使用java / scala中的bean功能：

import scala.beans.BeanProperty
import java.beans.Introspector

object BeanEx extends App { 
  case class Stuff(@BeanProperty val i: Int, @BeanProperty val j: String)
  val info = Introspector.getBeanInfo(classOf[Stuff])

  val instance = Stuff(10, "Hello")
  info.getPropertyDescriptors.map { p =>
    println(p.getReadMethod.invoke(instance))
  }
}

Scala：如何通过名称动态访问类属性？

2 个答案: