Reputation: 187

Can't read text from TextField input from DialogPane, JavaFX

I am trying to create a simple Contacts Application in JavaFX. It has a main window with TableView and a DialogPane opening when I want to create new contact. In the DialogPane there are several TextFields from which I want to collect text in order to create a Contacts List. My problem is that when I want to read the input from the DialogPane (from TextFields), which is the separate fxml file with separate controller (separate from main Controller) the application runs an error (java.lang.NullPointerException). And when I put a TextField in my main window FXML file, then I can access this text from the textField just fine. Why do I get an error when I want to read data from DialogPane (Error-->File: Controller.java, I commented the section where I get an error)?? I am stuck. Can anyone suggest what am I doing wrong? Here is my code:

Main.java

public class Main extends Application {

@Override
public void start(Stage primaryStage) throws Exception{
    Parent root = FXMLLoader.load(getClass().getResource("mainwindow.fxml"));
    primaryStage.setTitle("Your Contacts");
    primaryStage.setScene(new Scene(root, 900, 600));
    primaryStage.show();
}


public static void main(String[] args) {
    launch(args);
}
}

Controller.java

public class Controller {


@FXML
private BorderPane mainPanel;


public ObservableList<Contact> contactsList = FXCollections.observableArrayList();


@FXML
public void showAddContactDialog() {
    Dialog<ButtonType> dialog = new Dialog<>();
    dialog.initOwner(mainPanel.getScene().getWindow());
    dialog.setTitle("Add new contact");
    FXMLLoader fxmlLoader = new FXMLLoader();
    fxmlLoader.setLocation(getClass().getResource("addContactDialog.fxml"));
    try {
       dialog.getDialogPane().setContent(fxmlLoader.load());
    } catch (IOException e) {
        Alert alert = new Alert(Alert.AlertType.ERROR);
        alert.setTitle("Error");
        alert.setHeaderText(null);
        alert.setContentText("Couldn't load the dialog");
        alert.showAndWait();
        e.printStackTrace();
        return;
    }

    dialog.getDialogPane().getButtonTypes().add(ButtonType.OK);
    dialog.getDialogPane().getButtonTypes().add(ButtonType.CANCEL);

    Optional<ButtonType> result = dialog.showAndWait();
    if(result.isPresent() && result.get() == ButtonType.OK) {

    //========================================================================================

        //here is the error, I cannot read values from addContactDialog controller

        ContactController contactController = new ContactController();

        String firstName = contactController.getNewContact().getFirstName();
        String lastName = contactController.getNewContact().getLastName();
        String phoneNumber = contactController.getNewContact().getPhoneNumber();
        String emailAddress = contactController.getNewContact().getEmailAddress();

        Contact newContact = new Contact(firstName, lastName, phoneNumber, emailAddress);
        contactsList.add(newContact);

        //or alternatively
        //            Contact newContact = contactController.getNewContact();
        //            contactsList.add(newContact);


    //========================================================================================
    }

}
}

ContactController.java

public class ContactController {


@FXML
private TextField firstNameField;

@FXML
private TextField lastNameField;

@FXML
private TextField phoneNumberFiled;

@FXML
private TextField emailField;


public Contact getNewContact() {

    String firstName = firstNameField.getText();
    String lastName = lastNameField.getText();
    String phoneNumber = phoneNumberFiled.getText();
    String emailAddress = emailField.getText();

    Contact newContact = new Contact(firstName, lastName, phoneNumber, emailAddress);
    return newContact;
}

Contact.java

public class Contact {

private SimpleStringProperty firstName = new SimpleStringProperty("");
private SimpleStringProperty lastName = new SimpleStringProperty("");
private SimpleStringProperty phoneNumber = new SimpleStringProperty("");
private SimpleStringProperty emailAddress = new SimpleStringProperty("");

public Contact() {
}

public Contact(String firstName, String lastName, String phoneNumber, String emailAddress) {
    this.firstName.set(firstName);
    this.lastName.set(lastName);
    this.phoneNumber.set(phoneNumber);
    this.emailAddress.set(emailAddress);
}



public String getFirstName() {
    return firstName.get();
}

public SimpleStringProperty firstNameProperty() {
    return firstName;
}

public void setFirstName(String firstName) {
    this.firstName.set(firstName);
}

public String getLastName() {
    return lastName.get();
}

public SimpleStringProperty lastNameProperty() {
    return lastName;
}

public void setLastName(String lastName) {
    this.lastName.set(lastName);
}

public String getPhoneNumber() {
    return phoneNumber.get();
}

public SimpleStringProperty phoneNumberProperty() {
    return phoneNumber;
}

public void setPhoneNumber(String phoneNumber) {
    this.phoneNumber.set(phoneNumber);
}

public String getEmailAddress() {
    return emailAddress.get();
}

public SimpleStringProperty emailAddressProperty() {
    return emailAddress;
}

public void setEmailAddress(String emailAddress) {
    this.emailAddress.set(emailAddress);
}


@Override
public String toString() {
    return "Contact{" +
            "firstName=" + firstName +
            ", lastName=" + lastName +
            ", phoneNumber=" + phoneNumber +
            ", emailAddress=" + emailAddress +
            '}';
}
}

mainwindow.fxml

<BorderPane fx:id="mainPanel" fx:controller="sample.Controller"
        xmlns:fx="http://javafx.com/fxml">


<top>
    <MenuBar>
        <menus>
            <Menu text="Contacts">
                <items>
                    <MenuItem text="Add new" onAction="#showAddContactDialog"/>
                </items>
                <items>
                    <MenuItem text="Edit" />
                </items>
                <items>
                    <MenuItem text="Delete"/>
                </items>
                <items>
                    <MenuItem text="Exit"/>
                </items>
            </Menu>
        </menus>
        <menus>
            <Menu text="Info">
                <items>
                    <MenuItem text="About"/>
                </items>

            </Menu>
        </menus>
    </MenuBar>
</top>

<center>
    <TableView fx:id="contactsTable">
        <columnResizePolicy>
            <TableView fx:constant="CONSTRAINED_RESIZE_POLICY"/>
        </columnResizePolicy>
        <columns>
            <TableColumn text="First Name">
                <cellValueFactory>
                    <PropertyValueFactory property="firstName"/>
                </cellValueFactory>
            </TableColumn>

            <TableColumn text="Last Name">
                <cellValueFactory>
                    <PropertyValueFactory property="lastName"/>
                </cellValueFactory>
            </TableColumn>

            <TableColumn text="Phone Number">
                <cellValueFactory>
                    <PropertyValueFactory property="phoneNumber"/>
                </cellValueFactory>
            </TableColumn>

            <TableColumn text="Email">
                <cellValueFactory>
                    <PropertyValueFactory property="emailAddress"/>
                </cellValueFactory>
            </TableColumn>
        </columns>
    </TableView>
</center>
</BorderPane>

addContactDialog.fxml

<DialogPane fx:controller="sample.ContactController" xmlns:fx="http://javafx.com/fxml">
    <headerText>
    Fill in the information for the new Contact
</headerText>
<content>
    <GridPane vgap="10" hgap="10">
        <Label text="First Name: " GridPane.rowIndex="0" GridPane.columnIndex="0"/>
        <TextField fx:id="firstNameField" GridPane.rowIndex="0" GridPane.columnIndex="1"/>

        <Label text="Last Name: " GridPane.rowIndex="1" GridPane.columnIndex="0"/>
        <TextField fx:id="lastNameField" GridPane.rowIndex="1" GridPane.columnIndex="1"/>

        <Label text="Phone Number: " GridPane.rowIndex="2" GridPane.columnIndex="0"/>
        <TextField fx:id="phoneNumberField" GridPane.rowIndex="2" GridPane.columnIndex="1"/>

        <Label text="Notes: " GridPane.rowIndex="3" GridPane.columnIndex="0"/>
        <TextField fx:id="notesField" GridPane.rowIndex="3" GridPane.columnIndex="1"/>

    </GridPane>
</content>
</DialogPane>

Upvotes: 0