NullPointerException passing a string from a window to another - javafx

Question

Long story short, I searched for similar problems to mine, so I could troubleshoot this "by my own". I found these examples here and here, but none of them worked for me.
I need to pass to the next window a string that was typed in the TextField of the first window.
My main:
public class Main extends Application{
/**
* #param stage
* #throws java.lang.Exception
*/
#Override
public void start(Stage stage) throws Exception {
FXMLLoader floader = new FXMLLoader();
Parent root = FXMLLoader.load(getClass().getResource("java1.fxml"));
Java1Controller j1 = (Java1Controller)floader.getController();
Scene scene = new Scene(root);
stage.setScene(scene);
stage.setResizable(false);
stage.show();
}
public static void main(String[] args) {
launch(args);
}
}
As I'm using FXML, here's the controller of Window1 (java1):
public class Java1Controller implements Initializable {
#FXML
private TextField tSend;
#FXML
private Button bSend;
/**
* Initializes the controller class.
*/
#Override
public void initialize(URL url, ResourceBundle rb) {
// TODO
}
#FXML
private void sendText(ActionEvent event) throws IOException {
FXMLLoader fLd = new FXMLLoader();
Parent novo = FXMLLoader.load(getClass().getResource("java2.fxml"));
Java2Controller j2 = (Java2Controller)fLd.getController();
j2.setLbText(tSend.getText());
Scene novScene = new Scene(novo);
Stage novStage = (Stage)((Node)(event.getSource())).getScene().getWindow();
novStage.setScene(novScene);
novStage.setResizable(false);
novStage.show();
}
}
And the controller of Window2 (java2):
public class Java2Controller implements Initializable {
#FXML
private Label lbText;
#FXML
private Button bOK;
/**
* Initializes the controller class.
* #param url
* #param rb
*/
/**
* #param string the string to set
*/
public void setLbText(String string) {
lbText.setText(string);
}
#FXML
private void closeJPane(ActionEvent event) {
Stage stage = (Stage)((Node)(event.getSource())).getScene().getWindow();
stage.close();
}
#Override
public void initialize(URL url, ResourceBundle rb) {
// TODO
}
}
The problem is pointed to the Java1Controller line where I setText with my custom function (j2.setLbText). Why? If it matters, I'm using Netbeans 8.2 and JavaFX Scene Builder 11.0.
FXML Java1:
<Pane maxHeight="252.0" maxWidth="388.0" minHeight="252.0" minWidth="388.0" prefHeight="252.0" prefWidth="388.0" xmlns="http://javafx.com/javafx/11.0.1" xmlns:fx="http://javafx.com/fxml/1" fx:controller="main.Java1Controller">
<children>
<Label layoutX="126.0" layoutY="76.0" text="Insira texto aqui:">
<font>
<Font size="16.0" />
</font>
</Label>
<TextField fx:id="tSend" layoutX="109.0" layoutY="102.0" />
<Button fx:id="bSend" layoutX="169.0" layoutY="178.0" mnemonicParsing="false" onAction="#sendText" text="Send" />
</children>
</Pane>
FXML Java2:
<Pane maxHeight="388.0" maxWidth="252.0" minHeight="252.0" minWidth="388.0" prefHeight="252.0" prefWidth="388.0" xmlns="http://javafx.com/javafx/11.0.1" xmlns:fx="http://javafx.com/fxml/1" fx:controller="main.Java2Controller">
<children>
<Label fx:id="lbText" layoutX="137.0" layoutY="106.0" text="Texto enviado">
<font>
<Font size="16.0" />
</font>
</Label>
<Button fx:id="bOK" layoutX="164.0" layoutY="178.0" mnemonicParsing="false" onAction="#closeJPane" prefHeight="26.0" prefWidth="61.0" text="OK" />
</children>
</Pane>

Answer 1

You're using static load methods to load the fxmls. This way a new FXMLLoader instance is created by the method that you cannot get a reference to. The FXMLLoader instance you create yourself is never used to load an fxml file, so no controller is available via its getController property:
// here you create a loader without setting a location
FXMLLoader fLd = new FXMLLoader();
// here a static method uses another loader instance to load the fxml
Parent novo = FXMLLoader.load(getClass().getResource("java2.fxml"));
// here you try to retrieve the controller from the loader instance that is still in the same state as after the constructor completion
Java2Controller j2 = (Java2Controller)fLd.getController();
Change your code an use the loader instance you created yourself to load the fxml:
// create loader with location set
FXMLLoader fLd = new FXMLLoader(getClass().getResource("java2.fxml"));
// use loader instance to load fxml from location specified
Parent novo = fLd.load();
// the controller should now be available
Java2Controller j2 = (Java2Controller)fLd.getController();
assert j2 != null