Java - Is there any way to infer the object type from a reference type

Question

public static void printType(Object o){
  type = **someWayToDeduceTheObjectType()**
  fields = type.getDeclaredFields()
  System.out.println("The type of the object is : " + type);
  System.out.println("The fields of this type of class is : " + fields);
}

Is it possible to infer the object type of a passed object from a generic reference type?

If not, what is the reason?

I assume this is not possible, because of the existence of casting, but I can't pinpoint the exact reason.

EDIT: I'm not referring to instanceof operator here. Assume I don't have a list of Types to compare with.

http://stackoverflow.com/q/7313559/150818 – SJha Sep 23 '14 at 12:49 — SJha, Sep 23 '14 at 12:49

score 2 · Accepted Answer · answered Sep 23 '14 at 12:58

It's quite possible - you just call getClass():

public static void printType(Object o){
  type = o.getClass();
  fields = type.getDeclaredFields()
  System.out.println("The type of the object is : " + type);
  System.out.println("The fields of this type of class is : " + fields);
}

Java - Is there any way to infer the object type from a reference type

1 Answers1