javafx TextArea throws NullPointerException

Question

I m getting all the time NullPointerException. Any ideas what i m doing wrong ? i checked it is caused by TextArea. But i gave the id and identified the controller. I dont know why it is not seing it still ?!

public class YoutubeController extends Application{

@FXML
 TextArea area;


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

@Override
public void start(Stage primaryStage) throws Exception {


    Parent root= FXMLLoader.load(getClass().getResource("/youtube.fxml"));
    Scene scene = new Scene(root);
    primaryStage.setScene(scene);
    primaryStage.setResizable(false);
    primaryStage.setTitle("A.I.T YOUTUBE SEARCH");
    primaryStage.show();

}

@FXML
public void lyricsClicked(){
    Parent root;
    try {

        root = FXMLLoader.load(getClass().getResource("/lyrics.fxml"));
        Scene scene = new Scene(root);
        Stage stage = new Stage();
        stage.setScene(scene);
        stage.setResizable(false);
        stage.setTitle("Lyrics");
        area.setText(lyrics); // i checked lyrics and it is full of data
        stage.show();


    } catch (IOException e) {
        // TODO Auto-generated catch block
        e.printStackTrace();
    }

}

And Here is the fxml file.

<?xml version="1.0" encoding="UTF-8"?>

<?import javafx.scene.image.*?>
<?import javafx.scene.control.*?>
<?import javafx.scene.text.*?>
<?import java.lang.*?>
<?import javafx.scene.layout.*?>
<?import javafx.scene.layout.AnchorPane?>

<AnchorPane prefHeight="474.0" prefWidth="610.0" xmlns="http://javafx.com/javafx/8" xmlns:fx="http://javafx.com/fxml/1" fx:controller="youtube.YoutubeController" >
   <children>
      <TextArea fx:id="area" editable="false" layoutX="194.0" layoutY="64.0" prefHeight="474.0" prefWidth="610.0" AnchorPane.bottomAnchor="0.0" AnchorPane.leftAnchor="0.0" AnchorPane.rightAnchor="0.0" AnchorPane.topAnchor="0.0" />
   </children>
</AnchorPane>

Stacktrace:

EventDispatchChainImpl.dispatchEvent(EventDispatchChainImpl.java:114)
    at com.sun.javafx.event.EventUtil.fireEventImpl(EventUtil.java:74)
    at com.sun.javafx.event.EventUtil.fireEvent(EventUtil.java:49)
    at javafx.event.Event.fireEvent(Event.java:198)
    at javafx.scene.Node.fireEvent(Node.java:8216)
    at javafx.scene.control.Button.fire(Button.java:185)
    at com.sun.javafx.scene.control.behavior.ButtonBehavior.mouseReleased(ButtonBehavior.java:182)
    at com.sun.javafx.scene.control.skin.BehaviorSkinBase$1.handle(BehaviorSkinBase.java:96)
    at com.sun.javafx.scene.control.skin.BehaviorSkinBase$1.handle(BehaviorSkinBase.java:89)
    at com.sun.javafx.event.CompositeEventHandler$NormalEventHandlerRecord.handleBubblingEvent(CompositeEventHandler.java:218)
    at com.sun.javafx.event.CompositeEventHandler.dispatchBubblingEvent(CompositeEventHandler.java:80)
    at com.sun.javafx.event.EventHandlerManager.dispatchBubblingEvent(EventHandlerManager.java:238)
    at com.sun.javafx.event.EventHandlerManager.dispatchBubblingEvent(EventHandlerManager.java:191)
    at com.sun.javafx.event.CompositeEventDispatcher.dispatchBubblingEvent(CompositeEventDispatcher.java:59)
    at com.sun.javafx.event.BasicEventDispatcher.dispatchEvent(BasicEventDispatcher.java:58)
    at com.sun.javafx.event.EventDispatchChainImpl.dispatchEvent(EventDispatchChainImpl.java:114)
    at com.sun.javafx.event.BasicEventDispatcher.dispatchEvent(BasicEventDispatcher.java:56)
    at com.sun.javafx.event.EventDispatchChainImpl.dispatchEvent(EventDispatchChainImpl.java:114)
    at com.sun.javafx.event.BasicEventDispatcher.dispatchEvent(BasicEventDispatcher.java:56)
    at com.sun.javafx.event.EventDispatchChainImpl.dispatchEvent(EventDispatchChainImpl.java:114)
    at com.sun.javafx.event.EventUtil.fireEventImpl(EventUtil.java:74)
    at com.sun.javafx.event.EventUtil.fireEvent(EventUtil.java:54)
    at javafx.event.Event.fireEvent(Event.java:198)
    at javafx.scene.Scene$MouseHandler.process(Scene.java:3724)
    at javafx.scene.Scene$MouseHandler.access$1500(Scene.java:3452)
    at javafx.scene.Scene.impl_processMouseEvent(Scene.java:1728)
    at javafx.scene.Scene$ScenePeerListener.mouseEvent(Scene.java:2461)
    at com.sun.javafx.tk.quantum.GlassViewEventHandler$MouseEventNotification.run(GlassViewEventHandler.java:348)
    at com.sun.javafx.tk.quantum.GlassViewEventHandler$MouseEventNotification.run(GlassViewEventHandler.java:273)
    at java.security.AccessController.doPrivileged(Native Method)
    at com.sun.javafx.tk.quantum.GlassViewEventHandler.handleMouseEvent(GlassViewEventHandler.java:382)
    at com.sun.glass.ui.View.handleMouseEvent(View.java:553)
    at com.sun.glass.ui.View.notifyMouse(View.java:925)
Caused by: java.lang.reflect.InvocationTargetException
    at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
    at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
    at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
    at java.lang.reflect.Method.invoke(Method.java:483)
    at sun.reflect.misc.Trampoline.invoke(MethodUtil.java:71)
    at sun.reflect.GeneratedMethodAccessor1.invoke(Unknown Source)
    at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
    at java.lang.reflect.Method.invoke(Method.java:483)
    at sun.reflect.misc.MethodUtil.invoke(MethodUtil.java:275)
    at javafx.fxml.FXMLLoader$MethodHandler.invoke(FXMLLoader.java:1759)
    ... 43 more
Caused by: java.lang.NullPointerException
    at youtube.YoutubeController.lyricsClicked(YoutubeController.java:273)
    ... 53 more

Answer 1

Null pointer is caused by null in area, not in lyrics. Component related to lyrics.fxml is the same class as for youtube.fxml, but it has different instance! So you can not pass value in setText() to it.

You should get lyrics-component and access area from it instance:

public void setAreaText(String text) {
    area.setText(text);
}

@FXML
public void lyricsClicked() {
    Parent root;
    try {

        //root = FXMLLoader.load(getClass().getResource("/lyrics.fxml"));
        URL location = getClass().getResource("/lyrics.fxml");
        FXMLLoader fxmlLoader = new FXMLLoader();
        fxmlLoader.setLocation(location);
        fxmlLoader.setBuilderFactory(new JavaFXBuilderFactory());
        root = fxmlLoader.load(location.openStream());
        YoutubeController contr = fxmlLoader.getController();
        contr.setAreaText(lyrics);

        Scene scene = new Scene(root);
        Stage stage = new Stage();
        stage.setScene(scene);
        stage.setResizable(false);
        stage.setTitle("Lyrics");
        stage.show();

    } catch (IOException e) {
        // TODO Auto-generated catch block
        e.printStackTrace();
    }
}