BeanUtils.scala

// ---- Implementation

import java.beans.Introspector

object BeanUtils {
  val pathSeperator = """\."""

  def readValue(obj: Object, path: String): String = {
    val res = path.split(pathSeperator).foldLeft(obj) {
      (a: Object, prop: String) =>
        val sourceInfo = Introspector.getBeanInfo(a.getClass)
        val sourceDescriptors = sourceInfo.getPropertyDescriptors()
        val propertyDescriptor = sourceDescriptors.find(_.getName == prop).get
        propertyDescriptor.getReadMethod.invoke(a)
    }

    res.toString
  }
}

// ---- TESTCODE

import org.scalatest.matchers.ShouldMatchers
import org.scalatest.{FlatSpec}

class BeanUtilsSpec extends FlatSpec with ShouldMatchers {
  "BeanUtils" should "return a simple bean property as a string" in {
    BeanUtils.readValue(new Person("peter", null), "name") should equal("peter")
  }
  "BeanUtils" should "be capable of traversing a path" in {
    BeanUtils.readValue(new Person("peter", new Address("bellstraat", "hilversum")), "address.street") should equal("bellstraat")
  }
  "BeanUtils" should "throw a NoSuchElementException exception when a non-existing property is referenced" in {
    intercept[NoSuchElementException] {
      BeanUtils.readValue(new Person("peter", null), "apple")
    }
  }
}