java - Declare and iterate through ArrayList of classes that extend a class -

i may going wrong way, possible iterate through collection of classes extend specific class? i'm thinking of declaring :

arraylist<? extends interfacecomponent> components = new arraylist<? extends interfacecomponent>();

but throws error. possible?

edit : , iterate though :

    (<? extends interfacecomponent> t : components)     {         t.callsomemethod();     }

right?

try this:

arraylist<interfacecomponent> components = new arraylist<interfacecomponent>();

and on list can have object implements interfacecomponent.

edit: iterate this:

for (interfacecomponent t : components) { }

Cap