[FIXED] Objects.requireNonNull problem with my dialogflow chatbot app

Issue

That's the error:

The application is an interface with a dialogflow chatbot. The application is crushing when i set some text and i try to send it. Probably its because there is some depracated code, but i cant find a solution on the internet.

BTW that's the MainActivity.java:

public class MainActivity extends AppCompatActivity implements BotReply {

RecyclerView chatView;
ChatAdapter chatAdapter;
ArrayList<Message> messageList = new ArrayList<>();
EditText editMessage;
Button btnSend;

//dialogFlow
private SessionsClient sessionsClient;
private SessionName sessionName;
private final String uuid = UUID.randomUUID().toString();


@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_main);
    chatView = findViewById(R.id.rv_message);
    editMessage = findViewById(R.id.et_message);
    btnSend = findViewById(R.id.btn_mic);

    chatAdapter = new ChatAdapter(messageList, this);
    chatView.setAdapter(chatAdapter);

    btnSend.setOnClickListener(new View.OnClickListener() {
        @Override public void onClick(View view) {
            String message = editMessage.getText().toString();
            if (!message.isEmpty()) {
                messageList.add(new Message(message, false));
                editMessage.setText("");
                sendMessageToBot(message);
                Objects.requireNonNull(chatView.getAdapter()).notifyDataSetChanged();
                Objects.requireNonNull(chatView.getLayoutManager())
                        .scrollToPosition(messageList.size() - 1);
            } else {
                Toast.makeText(MainActivity.this, "Please enter text!", Toast.LENGTH_SHORT).show();
            }
        }
    });

    setUpBot();
}

private void setUpBot() {
    String TAG = "mainactivity";
    try {
        InputStream stream = this.getResources().openRawResource(R.raw.credentials);
        GoogleCredentials credentials = GoogleCredentials.fromStream(stream)
                .createScoped(Lists.newArrayList("https://www.googleapis.com/auth/cloud-platform"));
        String projectId = ((ServiceAccountCredentials) credentials).getProjectId();

        SessionsSettings.Builder settingsBuilder = SessionsSettings.newBuilder();
        SessionsSettings sessionsSettings = settingsBuilder.setCredentialsProvider(
                FixedCredentialsProvider.create(credentials)).build();
        sessionsClient = SessionsClient.create(sessionsSettings);
        sessionName = SessionName.of(projectId, uuid);

        Log.d(TAG, "projectId : " + projectId);
    } catch (Exception e) {
        Log.d(TAG, "setUpBot: " + e.getMessage());
    }
}



private void sendMessageToBot(String message) {
    QueryInput input = QueryInput.newBuilder()
            .setText(TextInput.newBuilder().setText(message).setLanguageCode("en-US")).build();
    new SendMessageInBg(this, sessionName, sessionsClient, input).execute();
}



@Override
public void callback(DetectIntentResponse returnResponse) {
    if(returnResponse!=null) {
        String botReply = returnResponse.getQueryResult().getFulfillmentText();
        if(!botReply.isEmpty()){
            messageList.add(new Message(botReply, true));
            chatAdapter.notifyDataSetChanged();
            Objects.requireNonNull(chatView.getLayoutManager()).scrollToPosition(messageList.size() - 1);
        }else {
            Toast.makeText(this, "something went wrong", Toast.LENGTH_SHORT).show();
        }
    } else {
        Toast.makeText(this, "failed to connect!", Toast.LENGTH_SHORT).show();
    }
}

}

I think the problem is here:

Objects.requireNonNull(chatView.getAdapter()).notifyDataSetChanged();
Objects.requireNonNull(chatView.getLayoutManager()).scrollToPosition(messageList.size() - 1);

If you need something else ask! Thanks

Solution

If the messageList is empty by default (and looks like it is) you have an empty recycler view and thus there are no non-fatal errors in the logs informing you that the recycler view is missing a layout manager. Set the layout manager to your chatView recycler view and it should be enough.

...
chatAdapter = new ChatAdapter(messageList, this);
chatView.setAdapter(chatAdapter);

// Add these two lines
LinearLayoutManager layoutManager = new LinearLayoutManager(this, LinearLayoutManager.VERTICAL, false);
chatView.setLayoutManager(layoutManager);

btnSend.setOnClickListener(new View.OnClickListener() {
...

Answered By - Jenea Vranceanu