Question

How to check if given class has specific field and if it is initialized (has value at the moment)?

abstract class Player extends GameCahracter {

}

public class Monster extends GameCahracter{

    public int level = 1;
}
abstract class GameCharacter{

   public void attack(GameCahracter opponent){

         if (opponent instanceof Monster && ){ // << here I have to know is it instance of Monster and if it has initialized value
           }
}

Answer 1

//Load the class 

Class clazz = Class.forName("your.class.ClassName");
Field field = clazz.getField("fieldName")
if(field!=null){
 //field exist now check if its initialized or not, or if its primitive field check against its assumed initialized value
 if(ClassName.fieldName!=null){
    //yes initilized
 }
}