随播对象的类

Question

How do i get the class that the companion object is representing? For Example:

val user = User("something")
val userClazz = user.getClass //returns somepackage.User

Now if i have a companion User object:

object User {
  def myClass = this.getClass //seems to return a different type of class somepackage.User$
}

My question is how do i get the "true" case classes class? I have an instance with reflection where this is causing me to get some strange "private" constructor while trying to use this.getClass inside of the companion object.

Answer 1

You can get the class of User with classOf[User] . Every (singleton) object has its own class. Companion object User is not an instance of class User .

Answer 2

Generally, you can't obtain the companion class, because the companion class might or might not exist or be class-loaded. Other than reflection, there is no way to do this in the language.

The recommended way is to declare a method in the companion object that returns the class, eg companionClass - this can be mandated with an interface that the object is extending.

Answer 3

Hate to answer my own question and i'd gladly mark someone else's the correct one if someone knows a better way but this is the hack i came up with for now and it seems to get me where i want to go.

val clazzName = this.getClass.getName
val clazz = Class.forName(clazzName.substring(0, clazzName.length - 1))