JavaFX: Populating a ComboBox with data from a MySQL Database, StringConverter breaking the combobox

I have a ComboBox, which I'd like to populate with data from a database. Using the following code, the data that is displayed in the ComboBox is the ID of the value, not the string value.

(Partial) Java Controller Code:

@FXML ComboBox studentPicker; @Override public void initialize(URL url, ResourceBundle rb) { String dbUsername = "root"; String dbPassword = "x"; String dbURL = "jdbc:mysql://localhost:3306/uia"; try { Connection conn = DriverManager.getConnection(dbURL, dbUsername, dbPassword); data = FXCollections.observableArrayList(); // Execute query and store result in a resultset ResultSet rs = conn.createStatement().executeQuery("SELECT username FROM user WHERE userrole='STUDENT';"); while (rs.next()) { //get string from db,whichever way data.add(new User(rs.getString("username"))); } } catch (SQLException ex) { System.err.println("Error"+ex); } studentPicker.setItems(null); studentPicker.setItems(data); } 

The StringConverter I tried was picked up from How to import database data into combo box in javafx, but this caused an error with the ComboBox. See image below: Image on the left is how it is supposed to be, right image is how it is when the StringConverter is added to the code.

studentPicker.setConverter(new StringConverter<User>() { @Override public String toString(User object) { return object.getName(); } @Override public User fromString(String string) { // TODO Auto-generated method stub return null; } }); 

What I'd like to display is the usernames collected from the Database, but ID's like "is20x.User@4b6ca8f7" is displayed instead. Any suggestion to how I can solve this problem is greatly appreciated.

2 Answers

Answering from my comment.

You are adding a new User("username") to your data array which is why you are getting a weird String, its the ID of that particular User.

Try instead doing data.add(new User(rs.getString("username")).getUserName());, if you User class has a getUserName() method.

This may break what you are trying to do all around though, as I assume you use data more that just here. It might be best to make another variable and store you comboBox strings in that. So something like

//Init same place data is comboString = FXCollections.observableArrayList(); //Declared somewhere else data.add(new User(rs.getString("username"))); comboString.add(rs.getString("username")); 

I want to share what I did to automatically set the data from MySQL database. (that is very simple)

 // first I execute the query that select name of department one by one resultSet = statement.executeQuery("Select name from department"); while (resultSet.next()) { // loop // Now add the comboBox addAll statement comboBox.getItems().addAll(resultSet.getString("name")); } 

note here the "name" field in last line, is exactly spelled same as the name of the column in MySQL table.