Hey Nick, let's tackle your two main issues step by step—syncing TableView changes to your CSV file and implementing the edit functionality with a new scene. I'll break this down into actionable code changes and explanations.

1. First: Ensure Your Gebruiker Class is Fully Implemented #

The PropertyValueFactory and edit functionality rely on proper getters and setters. Here's the complete class you need:

public class Gebruiker {
    private String voornaam;
    private String achternaam;

    public Gebruiker(String voornaam, String achternaam) {
        this.voornaam = voornaam;
        this.achternaam = achternaam;
    }

    // Getters for TableView column binding
    public String getVoornaam() {
        return voornaam;
    }

    public String getAchternaam() {
        return achternaam;
    }

    // Setters for edit functionality
    public void setVoornaam(String voornaam) {
        this.voornaam = voornaam;
    }

    public void setAchternaam(String achternaam) {
        this.achternaam = achternaam;
    }
}

2. Add CSV Sync Logic (Read/Write) #

Right now, your app loads data but doesn't save changes back to the CSV. Let's add two helper methods for this.

2.1 Load CSV Data on App Startup #

Add this method to load existing users from your CSV into the dataList:

private void loadCsvData() {
    String csvPath = "gebruikers.csv"; // Replace with your actual file path
    String csvDelimiter = ",";

    try (BufferedReader reader = new BufferedReader(new FileReader(csvPath))) {
        // Skip header row if your CSV has one (uncomment below)
        // reader.readLine();

        String line;
        while ((line = reader.readLine()) != null) {
            String[] userData = line.split(csvDelimiter);
            if (userData.length == 2) {
                dataList.add(new Gebruiker(userData[0].trim(), userData[1].trim()));
            }
        }
    } catch (FileNotFoundException e) {
        Logger.getLogger(Main.class.getName()).log(Level.SEVERE, "CSV file not found!", e);
    } catch (IOException e) {
        Logger.getLogger(Main.class.getName()).log(Level.SEVERE, "Error reading CSV!", e);
    }
}

Call this method in your start() right after initializing the table:

// After table.setItems(dataList) and adding columns
loadCsvData();

2.2 Write Changes Back to CSV #

Add this method to save the dataList to CSV whenever you add/edit/delete a user:

private void writeCsvData() {
    String csvPath = "gebruikers.csv"; // Same path as load method

    try (PrintWriter writer = new PrintWriter(new FileWriter(csvPath))) {
        // Optional: Write header row
        // writer.println("Voornaam,Achternaam");

        for (Gebruiker user : dataList) {
            writer.println(user.getVoornaam() + "," + user.getAchternaam());
        }
    } catch (IOException e) {
        Logger.getLogger(Main.class.getName()).log(Level.SEVERE, "Error writing to CSV!", e);
    }
}

3. Fix the "Add" Functionality to Sync with CSV #

Complete your saveButtonAddClicked() method to add the user to the list AND save to CSV:

private void saveButtonAddClicked() {
    String voornaam = voornaamInput.getText().trim();
    String achternaam = achternaamInput.getText().trim();

    if (!voornaam.isEmpty() && !achternaam.isEmpty()) {
        dataList.add(new Gebruiker(voornaam, achternaam));
        writeCsvData(); // Sync changes to CSV
        ((Stage) voornaamInput.getScene().getWindow()).close(); // Close the add window
    } else {
        Alert errorAlert = new Alert(Alert.AlertType.ERROR);
        errorAlert.setTitle("Fout");
        errorAlert.setContentText("Voer zowel een voornaam als achternaam in!");
        errorAlert.showAndWait();
    }
}

4. Implement the "Edit" Functionality #

First, add an edit button to your main button bar:

Button editButton = new Button("Bewerken");
editButton.setOnAction(e -> openEditWindow());

Then add the openEditWindow() method to handle the edit scene and update logic:

private void openEditWindow() {
    Gebruiker selectedUser = table.getSelectionModel().getSelectedItem();
    if (selectedUser == null) {
        Alert warningAlert = new Alert(Alert.AlertType.WARNING);
        warningAlert.setTitle("Waarschuwing");
        warningAlert.setContentText("Selecteer eerst een gebruiker om te bewerken!");
        warningAlert.showAndWait();
        return;
    }

    // Build the edit window UI
    Label titleLabel = new Label("Bewerk gebruiker");
    HBox titleLayout = new HBox(titleLabel);
    titleLayout.setPadding(new Insets(10));

    TextField editVoornaam = new TextField(selectedUser.getVoornaam());
    editVoornaam.setPromptText("Voornaam");
    TextField editAchternaam = new TextField(selectedUser.getAchternaam());
    editAchternaam.setPromptText("Achternaam");

    VBox inputLayout = new VBox(10, editVoornaam, editAchternaam);
    inputLayout.setPadding(new Insets(10));

    // Save button logic
    Button saveEditBtn = new Button("Opslaan");
    saveEditBtn.setOnAction(e -> {
        String newVoornaam = editVoornaam.getText().trim();
        String newAchternaam = editAchternaam.getText().trim();

        if (!newVoornaam.isEmpty() && !newAchternaam.isEmpty()) {
            selectedUser.setVoornaam(newVoornaam);
            selectedUser.setAchternaam(newAchternaam);
            table.refresh(); // Update TableView display
            writeCsvData(); // Sync changes to CSV
            ((Stage) saveEditBtn.getScene().getWindow()).close();
        } else {
            Alert errorAlert = new Alert(Alert.AlertType.ERROR);
            errorAlert.setTitle("Fout");
            errorAlert.setContentText("Voer zowel een voornaam als achternaam in!");
            errorAlert.showAndWait();
        }
    });

    Button cancelBtn = new Button("Annuleren");
    cancelBtn.setOnAction(e -> ((Stage) cancelBtn.getScene().getWindow()).close());

    HBox buttonLayout = new HBox(10, saveEditBtn, cancelBtn);
    buttonLayout.setPadding(new Insets(10));
    buttonLayout.setAlignment(Pos.CENTER);

    // Assemble the scene
    BorderPane editPane = new BorderPane();
    editPane.setTop(titleLayout);
    editPane.setCenter(inputLayout);
    editPane.setBottom(buttonLayout);

    Scene editScene = new Scene(editPane, 600, 400);
    Stage editWindow = new Stage();
    editWindow.setTitle("JavaFX - Bewerken");
    editWindow.setScene(editScene);
    editWindow.initModality(Modality.WINDOW_MODAL);
    editWindow.initOwner(window);
    editWindow.showAndWait();
}

5. Fix the "Delete" Functionality to Sync with CSV #

Update your delete button logic to save changes to CSV after removing a user:

Button deleteButton = new Button("Verwijder");
deleteButton.setOnAction(e -> {
    Gebruiker selectedUser = table.getSelectionModel().getSelectedItem();
    if (selectedUser != null) {
        dataList.remove(selectedUser);
        writeCsvData(); // Sync deletion to CSV
    } else {
        Alert warningAlert = new Alert(Alert.AlertType.WARNING);
        warningAlert.setTitle("Waarschuwing");
        warningAlert.setContentText("Selecteer eerst een gebruiker om te verwijderen!");
        warningAlert.showAndWait();
    }
});

Don't forget to add this button to your main button layout (alongside "Toevoegen" and "Bewerken").

Quick Notes #

• Ensure your CSV file is in the correct path relative to your app, or use an absolute path if needed
• If the CSV file doesn't exist yet, the writeCsvData() method will create it automatically on first save
• For a more polished experience, you could use JavaFX StringProperty in the Gebruiker class instead of plain strings—this would let the TableView auto-update without calling table.refresh()

内容的提问来源于stack exchange，提问作者Nick van Bruggen