I want to display the item on the Android fragment, but it doesn't work.

public class ItemListFragment extensions ListFragment{

private Callbacks mCallbacks =sDummyCallbacks;
public classGroupSpinnerItem{
    public boolean isGroup;// group flag
    public String itemName;// Item name

    publicGroupSpinnerItem(boolean isGroup, StringitemName){
        This.isGroup = isGroup;
        This.itemName =itemName;
    }
}

public interface Callbacks {

    void onItemSelected (String id);
}

private static CallbackssDummyCallbacks=newCallbacks(){
    @ Override
    public void onItemSelected (String id) {
    }
};

@ Override
public void onCreate (Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);

        GroupSpinnerAdapter=newGroupSpinnerAdapter(getContext());

            adapter.addItem(newGroupSpinnerItem(true, "group"));
            adapter.addItem(newGroupSpinnerItem(false, "1"));
            adapter.addItem(newGroupSpinnerItem(false, "2"));
            adapter.addItem(newGroupSpinnerItem(false, "3"));
            setListAdapter (adapter);
            }

public classGroupSpinnerAdapter extensions BaseAdapter {
public static ArrayList<ItemListFragment.GroupSpinnerItem>itemList=newArrayList<ItemListFragment.GroupSpinnerItem>();
public static LayoutInflater inflater;
publicGroupSpinnerAdapter(Contextcontext){
    inflater=(LayoutInflater) context.getSystemService(Context.LAYOUT_INFLATER_SERVICE);
}
public static void addItem(ItemListFragment.GroupSpinnerItem){
    itemList.add(item);
}
public intgetCount(){
    return itemList.size();
}
publicObjectgetItem(int position){
    return itemList.get(position);
}
public long getItemId(int position){
    return position;
}
publicView getView(int position, View convertView, ViewGroup parent) {
    return createView(position, convertView, parent, false);
}
@ Override
public View getDropDownView(int position, View convertView,
            ViewGroup parent) {
    return createView(position, convertView, parent, true);
}
publicView createView(int position, View convertView, ViewGroup parent, boolean isDropDown){
    TextView tvName = null;
    if(convertView instance of TextView) {
        tvName=(TextView) convertView;
    }
    if(tvName==null){
        tvName=(TextView) inflater.inflate(android.R.layout.simple_spinner_item, parent, false);
    }
    ItemListFragment.GroupSpinnerItem=itemList.get(position);
    if(item.isGroup){
        if(isDropDown){
            tvName.setTypeface(Typeface.create(Typeface.DEFAULT,Typeface.BOLD));
            tvName.setText(item.itemName);
            tvName.setBackgroundColor (Color.BLUE);
        }
    }
    else{
        String text="+item.itemName;
        tvName.setText(text);
        tvName.setBackgroundColor (Color.TRANSPARENT);
    }
    return tvName;
}
@ Override
public boolean isEnabled (int position) {
    return(itemList.get(position).isGroup==false);
}
}