CustomAdapter的getView方法中的NullPointerException

Question

public class DayAdapter extends BaseAdapter {

    private Context mContext;
    private Day[] mDays;

    public DayAdapter(Context context, Day[] days) {
        mContext = context;
        mDays = days;
    }

    @Override
    public int getCount() {
        return mDays.length;
    }

    @Override
    public Object getItem(int i) {
        return mDays[i];
    }

    @Override
    public long getItemId(int i) {
        return 0;
    }

    @Override
    public View getView(int i, View view, ViewGroup viewGroup) {

        ViewHolder holder;

        if(view==null){
            view = LayoutInflater.from(mContext).inflate(R.layout.daily_list_item, null);
            holder = new ViewHolder();
            holder.iconImageView = (ImageView) view.findViewById(R.id.iconImageView);
            holder.dayLabel = (TextView) view.findViewById(R.id.dayNameLabel);
            holder.temperatureLabel = (TextView) view.findViewById(R.id.temperatureLabel);
            view.setTag(holder);
        }else{
            holder = (ViewHolder) view.getTag();
        }
        Day day = mDays[i];
        holder.dayLabel.setText(day.getDayOfTheWeek());

        holder.temperatureLabel.setText(day.getMaxTemperature()+"");
        holder.iconImageView.setImageResource(day.getIconId());

        return view;
    }

    private static class ViewHolder{
        ImageView iconImageView;
        TextView temperatureLabel;
        TextView dayLabel;
    }
}

我得到例外：

FATAL EXCEPTION: main
java.lang.NullPointerException at app.com.example.tmrovsky.czywgdynipada.Adapters.DayAdapter.getView(DayAdapter.java:62)

在设置这三项时，我不知道哪里出错： holder.dayLabel.setText(day.getDayOfTheWeek());等等。我试图调试，没有空值（它是正确的Tueasday）。有什么想法，我的兄弟们？ ：）