EDIT: Example code for creating list of objects from JsonArray.
ArrayList<MyObject> myList = new ArrayList<MyObject>();
public void parseJsonObjectIntoStorage(JsonArray data) {
for (int i = 0; i < data.size(); i++) {
JsonObject jsonObject = data.get(i).getAsJsonObject();
// Your class should have a constructor that accepts a JsonObject
// and constructs your object with GSON
MyObject obj = new MyObject(jsonObject);
myList.add(obj);
}
}
First, you will need to parse the JSON into objects, which can be put into a list to feed into your adapter. I recommend GSON for taking care of this.
Here's a great tutorial for using ListViews. It also describes ExpandableListViews, which if I understand your question, is what you are looking for.