Scala reflection to access all public fields at runtime

Question

Given the following class hierarchy:

class A {
  val x = 3
  val y = 4
}

class B extends A {
  val z = 5
}

And say I have an instance of B

Answer 1

Here is a slightly other way to do it:

scala> val i = 10
i: Int = 10

scala> val ru=scala.reflect.runtime.universe
ru: scala.reflect.api.JavaUniverse = scala.reflect.runtime.JavaUniverse@2096fb9f

scala> val m = ru.runtimeMirror(getClass.getClassLoader)
m: ru.Mirror = JavaMirror with scala.tools.nsc.interpreter.IMain$TranslatingClassLoader@3ae5ce58 of type class scala.tools.nsc.interpreter.IMain$TranslatingClassLoader with classpath [(memory)] and parent being scala.tools.nsc.util.ScalaClassLoader$URLClassLoader@454e119d of type class scala.tools.nsc.util.ScalaClassLoader$URLClassLoader with classpath [file:/Library/Java/JavaVirtualMachines/jdk1.7.0_45.jdk/Contents/Home/jre/lib/resources.jar,file:/Library/Java/JavaVirtualMachines/jdk1.7.0_45.jdk/Contents/Home/jre/lib/rt.jar,file:/Library/Java/JavaVirtualMachines/jdk1.7.0_45.jdk/Contents/Home/jre/lib/jsse.jar,file:/Library/Java/JavaVirtualMachines/jdk1.7.0_45.jdk/Contents/Home/jre/lib/jce.jar,file:/Library/Java/JavaVirtualMachines/jdk1.7.0_45.jdk/Contents/Home/jre/lib/charsets.jar,file:...
scala> val im=m.reflect(i)
im: ru.InstanceMirror = instance mirror for 10

scala> val is =im.symbol
is: ru.ClassSymbol = class Int

scala> val ims=is.toType.members
ims: ru.MemberScope = Scopes(method getClass, constructor Int, method ##, method asInstanceOf, method isInstanceOf, method toString, method hashCode, method equals, method !=, method ==, method %, method %, method %, method %, method %, method %, method %, method /, method /, method /, method /, method /, method /, method /, method *, method *, method *, method *, method *, method *, method *, method -, method -, method -, method -, method -, method -, method -, method +, method +, method +, method +, method +, method +, method +, method ^, method ^, method ^, method ^, method ^, method &, method &, method &, method &, method &, method |, method |, method |, method |, method |, method >=, method >=, method >=, method >=, method >=, method >=, method >=, method >, method >, method >, met...
scala> 

ims can then be further filtered any way you like.