JavaFX Progress Indicator Not Visible - javafx

Question

Hi I am writing a custom login dialog. I want to display a progress indicator while my users credentials are verified. When I run my button handler the progress indicator does not appear even though I call the setVisible(true) method. Also the text is not visible either.
#FXML
private void handleLoginButton2(ActionEvent event) {
//username and password required
if (userNameTextField.getText().isEmpty() || passwordTextField.getText().isEmpty()) {
Alert alert = new Alert(Alert.AlertType.ERROR);
alert.setTitle("Login Validation");
alert.setHeaderText("Validation Failed");
String msg = "Please input user name and password.";
alert.setContentText(msg);
alert.showAndWait();
} else {
try {
loginProgressIndicator.setVisible(true);
loginStatusText.setText("Authorising...");
Class.forName(JDBC_DRIVER2);
String user = userNameTextField.getText();
String password = passwordTextField.getText();
Connection conn = DriverManager.getConnection(JDBC_URL2, user, password);
loginStatusText.setText("Authorisation Successful");
loginProgressIndicator.setVisible(false);
//close login window
windowManager.closeLoginWindow();
//open main screen
windowManager.showMainView();
} catch (ClassNotFoundException | SQLException | IOException ex) {
Logger.getLogger(LoginController.class.getName()).log(Level.SEVERE, null, ex);
loginStatusText.setText("Authorisation Failed");
loginProgressIndicator.setVisible(false);
}
}
}

Answer 1

Do the DB access from a task running in a seperate thread and handle the results in the onSucceeded/onFailed event handlers:
public class AuthorizeTask extends Task<Void> {
private static final String JDBC_DRIVER = "com.mysql.jdbc.Driver";
private static final String JDBC_URL = "jdbc:mysql://localhost:3306/victorydb?zeroDateTimeBehavior=convertToNull";
private final String user;
private final String password;
public AuthorizeTask(String user, String password) {
if (user == null || password == null) {
throw new IllegalArgumentException();
}
this.user = user;
this.password = password;
}
#Override
protected Void call() throws Exception {
Class.forName(JDBC_DRIVER);
Connection conn = DriverManager.getConnection(JDBC_URL, this.user, this.password);
return null;
}
}
Task<Void> task = new AuthorizeTask(userNameTextField.getText(), passwordTextField.getText());
task.setOnFailed(evt -> {
Logger.getLogger(LoginController.class.getName()).log(Level.SEVERE, null, task.getException());
loginStatusText.setText("Authorisation Failed");
loginProgressIndicator.setVisible(false);
});
task.setOnSucceeded(evt -> {
// you may need to add a try/catch here
loginStatusText.setText("Authorisation Successful");
loginProgressIndicator.setVisible(false);
//close login window
windowManager.closeLoginWindow();
//open main screen
windowManager.showMainView();
});
loginProgressIndicator.setVisible(true);
loginStatusText.setText("Authorising...");
// run this on background thread to avoid blocking the application thread
new Thread(task).start();
You may want to change the type parameter of Task to Connection though, since you probably need to work with the Connection later...