java - From Class<? extends X> to X -


i working on reflexion stuff , i'm beginner @ it.

i got :

list<x> list; set<class<? extends x>> set;

and want :

for (class<? extends x> classx : set) list.add(classx);

but couldn't find on how achieve it. can me?

you can't achieve such behavior input data. list<x> list expected instance of class x, you're trying add object of type class<? extends x>. let's imagine type x number(for simplicity), have double, integer, character , etc, children of number. so, you're doing next thing: want add object of type class<integer> list can hold numbers(not class<integer>, class<double> , on). thing can do, it's create instance of class<integer>, class<double> way, using reflection:

list<x> list = //some values; set<class<? extends x>> set = //some values; (class<? extends x> classx : set) list.add(classx.newinstance());

but that's bad idea use reflection in such way. maybe meant this: 

list<class<x>> list = //some values; set<class<? extends x>> set = //some values; (class<? extends x> classx : set) list.add(classx);

because still class<x> not same class<? extends x>. maybe meant this:

list<x> list = //some values; set<? extends x> set = = //some values; (x elem : set) list.add(elem);

last 1 looks nice , should work.


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