setText(String) error

private View mFactTextView = findViewById(R.id.textView);
private View mShowFactButton;
/**
 * ATTENTION: This was auto-generated to implement the App Indexing API.
 * See https://g.co/AppIndexing/AndroidStudio for more information.
 */
private GoogleApiClient mClient;

@Override
// Create method
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_fun_facts);

    // Assign the views from the layout file to the corresponding variables
    mShowFactButton = findViewById(R.id.button);

    View.OnClickListener listener = new View.OnClickListener() {
        @Override
        public void onClick(View v) {
            // The button was clicked, so update the fact TextView with a new fact
            String fact = "Ostriches can run faster horses";
            mFactTextView.setText(fact); {
            }
        }
    };
    mShowFactButton.setOnClickListener(listener);
    // ATTENTION: This was auto-generated to implement the App Indexing API.
    // See https://g.co/AppIndexing/AndroidStudio for more information.
    mClient = new GoogleApiClient.Builder(this).addApi(AppIndex.API).build();
}

@Override
public void onStart() {
    super.onStart();

    // ATTENTION: This was auto-generated to implement the App Indexing API.
    // See https://g.co/AppIndexing/AndroidStudio for more information.
    mClient.connect();
    Action viewAction = Action.newAction(
            Action.TYPE_VIEW, // TODO: choose an action type.
            "FunFacts Page", // TODO: Define a title for the content shown.
            // TODO: If you have web page content that matches this app activity's content,
            // make sure this auto-generated web page URL is correct.
            // Otherwise, set the URL to null.
            Uri.parse("http://host/path"),
            // TODO: Make sure this auto-generated app URL is correct.
            Uri.parse("android-app://com.example.blessdat.funfacts/http/host/path")
    );
    AppIndex.AppIndexApi.start(mClient, viewAction);
}

@Override
public void onStop() {
    super.onStop();

    // ATTENTION: This was auto-generated to implement the App Indexing API.
    // See https://g.co/AppIndexing/AndroidStudio for more information.
    Action viewAction = Action.newAction(
            Action.TYPE_VIEW, // TODO: choose an action type.
            "FunFacts Page", // TODO: Define a title for the content shown.
            // TODO: If you have web page content that matches this app activity's content,
            // make sure this auto-generated web page URL is correct.
            // Otherwise, set the URL to null.
            Uri.parse("http://host/path"),
            // TODO: Make sure this auto-generated app URL is correct.
            Uri.parse("android-app://com.example.blessdat.funfacts/http/host/path")
    );
    AppIndex.AppIndexApi.end(mClient, viewAction);
    mClient.disconnect();
}