I'm trying to make it popular with my list view with a json, it checks the information of another json and returns me a link in which I'll use it to fill in photos, but everything happens right with you setar the link in a class but in the moment of receiving it always I get null
GET.class
You create the Task
new fotolist(activity, lv, teste).execute("http://infasstec.com.br/desenvolvimento/android/foto.json");
But you are not using the result that is inside it.
Save to instance
fotos = new fotolist(activity, lv, teste).execute("http://infasstec.com.br/desenvolvimento/android/foto.json");
And then on a button action for example you can get the link with fotos.link
Another thing, you are setting the link inside a for, you will only have the last given when you use it, you may want to use a List instead of String
PS: Use CamelCase on behalf of classes.