片段内listview的adapter.notifyDataSetChanged()崩溃

我在片段的onCreateView()中有一个arraylist,它包含listview中要更新的数据,我使用接口回调来更新另一个活动的数据,如下所示:

listUpdatable.update(nameStr,otpStr,timeStr);

   @Override
public void update(String name, String time, String otp) {
    SentMessageModel message = new SentMessageModel();
    message.setOtp(otp);
    message.setName(name);
    message.setTime(time);
    messages.add(0, message);
    adapter.notifyDataSetChanged();
}

app carashes on calling update方法正在arraylist上显示NPE。 我该怎么办?

View view = inflater.inflate(R.layout.fragment_sent_message_history, container, false);
    ListView listView = view.findViewById(R.id.sent_message_listView);
    emptyText = view.findViewById(R.id.empty_text);
    messages = new ArrayList<>();
    databaseCodeForAll(); // fetches the content of messages arraylist from  sqlite
    adapter = new SentMessageAdapter(getContext(), messages);
    listView.setAdapter(adapter);