Java NullPointerException TavleView.setItem(FXCollections.observableArrayList())

Question

I want to add in my Tabel (personTable in Personen_detailController) a column but when I set the ObservableList<> it tells me NullPointerException. The person, which I need is in the List and it gives me the right parameter when I do System.out.println(per.getPersonId()).

I don't know what I am doing wrong because in my PersonenController I do the same thing and it's working.

I will post every class that is necessary. I appreciate your help.

PersonenController:

package dummy.dummy.dummy.personen;

import dummy.dummy.InformationDialog;
import dummy.model.Person;
import java.net.URL;
import java.util.ArrayList;
import java.util.ResourceBundle;
import javafx.collections.FXCollections;
import javafx.collections.ObservableList;
import javafx.event.ActionEvent;
import javafx.event.EventHandler;
import javafx.fxml.FXML;
import javafx.fxml.Initializable;
import javafx.scene.control.Alert;
import javafx.scene.control.Button;
import javafx.scene.control.ContentDisplay;
import javafx.scene.control.TableCell;
import javafx.scene.control.TableColumn;
import javafx.scene.control.TableView;
import javafx.scene.control.TextField;
import javafx.scene.control.cell.PropertyValueFactory;
import javafx.scene.input.KeyCode;
import javafx.scene.input.KeyEvent;
import javafx.util.Callback;

/**
 * FXML Controller class
 *
 * @author z0035ddc
 */
public class PersonenController implements Initializable {

    String filterText = null;

    ArrayList<Person> PerList;
    ObservableList<Person> personSuchList = FXCollections.observableArrayList();

    Personen_detailController detailController = new Personen_detailController();


    @FXML
    TableView<Person> personSuchTable;


    @FXML
    TextField Name_TextFeld;
    @FXML
    TextField Kurzname_TextFeld;


    @Override
    public void initialize(URL url, ResourceBundle rb) {

    }    

    @FXML
    private void search() {

        if(!Name_TextFeld.getText().equals("") && Kurzname_TextFeld.getText().equals("")){ // Falls nach Name gesucht wird
            filterText = Name_TextFeld.getText();
            filterText = filterText.replace("*", "%");
            perListByName();
        }else if(!Kurzname_TextFeld.getText().equals("") && Name_TextFeld.getText().equals("")){ // Falls nach Kurnamen gesucht wird
            filterText = Kurzname_TextFeld.getText();
            filterText = filterText.replace("*", "%");
            perListByShortname();
        }else if(Name_TextFeld.getText().equals("") && Kurzname_TextFeld.getText().equals("")){ // Falls Textfelder nicht befüllt
            InformationDialog dia = new InformationDialog(Alert.AlertType.INFORMATION, "Bitte geben Sie einen Namen bzw. Kurznamen ein.");
        }else if(!Name_TextFeld.getText().equals("") && !Kurzname_TextFeld.getText().equals("")){ // Falls beide Textfelder befüllt
            InformationDialog dia = new InformationDialog(Alert.AlertType.INFORMATION, "Es dürfen nicht gleichzeitig Name und Kurzname gefüllt sein.");
        }

        /*****************************FEHLER!!!***************************/

        if(!PerList.isEmpty()){

            personSuchList.clear();
            personSuchTable.getColumns().clear();

            for (Person per : PerList) {
                personSuchList.add(per);
            }

            personSuchTable.setItems(personSuchList);
            initTable();


        }else{

            InformationDialog dia = new InformationDialog(Alert.AlertType.INFORMATION, "Person wurde nicht gefunden.");

        }

    }

    private void perListByName(){
        PerList = new ArrayList<>();
        PerList = Person.getListPersonenAndDoQueryByName(filterText);
    }

    private void perListByShortname(){
        PerList = new ArrayList<>();
        PerList = Person.getListPersonenAndDoQueryByShortname(filterText);
    }    

    @FXML
    private void searchByEnter(KeyEvent event){
        if (event.getCode() == KeyCode.ENTER || event == null) {
            search();
        }
    }

    @FXML
    private void initTable() {
                //Erste Spalte                
                TableColumn personId = new TableColumn();
                personId.setText("Person_ID");
                personId.setMinWidth(50);
                personId.setCellValueFactory(new PropertyValueFactory("personId"));
                personSuchTable.getColumns().add(personId);

                //Zweite Spalte

                TableColumn kurzname = new TableColumn();
                kurzname.setText("Kurzname");
                kurzname.setMinWidth(50);
                kurzname.setCellValueFactory(new PropertyValueFactory("kurzname"));
                personSuchTable.getColumns().add(kurzname);

                //dritte Spalte

                TableColumn name = new TableColumn();
                name.setText("NAME");
                name.setMinWidth(100);
                name.setCellValueFactory(new PropertyValueFactory("name"));
                personSuchTable.getColumns().add(name);

                //vierte Spalte

                TableColumn Land = new TableColumn();
                Land.setText("Land");
                Land.setMinWidth(50);
                Land.setCellValueFactory(new PropertyValueFactory("land"));
                personSuchTable.getColumns().add(Land);

                //fünfte Spalte

                TableColumn sperre = new TableColumn();
                sperre.setText("Gesperrt");
                sperre.setMinWidth(5);
                sperre.setCellValueFactory(new PropertyValueFactory("sperre"));
                personSuchTable.getColumns().add(sperre);

                //fünfte Spalte

                TableColumn<Person, Boolean> detail = new TableColumn<>();
                detail.setText("");
                detail.setMinWidth(150);
                Callback<TableColumn<Person, Boolean>, TableCell<Person, Boolean>> detailsColumnCellFactory = //
                new Callback<TableColumn<Person, Boolean>, TableCell<Person, Boolean>>() {

            @Override
            public TableCell call(final TableColumn param) {
                final TableCell cell = new TableCell() {

                    @Override
                    public void updateItem(Object item, boolean empty) {
                        super.updateItem(item, empty);
                        if (empty) {
                            setText(null);
                            setGraphic(null);
                        } else {
                            final Button btnDetail = new Button("Details");
                            btnDetail.setOnAction(new EventHandler<ActionEvent>() {

                                @Override
                                public void handle(ActionEvent event) {
                                    param.getTableView().getSelectionModel().select(getIndex());
                                    Person item = personSuchTable.getSelectionModel().getSelectedItem();
                                    if (item != null) {

                                        detailController.openNewPersonTab(item);
                                    }
                                }
                            });
                            setGraphic(btnDetail);
                            setContentDisplay(ContentDisplay.GRAPHIC_ONLY);
                        }
                    }
                };
                return cell;
            }
        };
        detail.setCellFactory(detailsColumnCellFactory);
        personSuchTable.getColumns().add(detail);
    }   
}

in line 196 I call my Person_detailController class (detailController.openNewPersonTab(item);).

Personen_detailController:

package admintool.ui.stammdaten.personen;

import admintool.AdminTool;
import admintool.helpers.ExceptionDialog;
import admintool.model.Person;
import admintool.ui.steuerdaten.benutzerverwaltung.BenutzerSucheController;
import java.io.IOException;
import java.util.logging.Level;
import java.util.logging.Logger;
import javafx.collections.FXCollections;
import javafx.collections.ObservableList;
import javafx.fxml.FXML;
import javafx.fxml.FXMLLoader;
import javafx.scene.control.Alert;
import javafx.scene.control.Tab;
import javafx.scene.control.TabPane;
import javafx.scene.control.TableColumn;
import javafx.scene.control.TableView;
import javafx.scene.control.TextField;
import javafx.scene.control.cell.PropertyValueFactory;

/**
 *
 * @author z0035ddc
 */
public class Personen_detailController {

    Person per;

    @FXML
    TableView<Person> personTable;

    ObservableList<Person> personList = FXCollections.observableArrayList();

    @FXML
    TextField name_TextFeld_detail;
    @FXML
    TextField land_TextFeld_detail;
    @FXML
    TextField personId_TextFeld_detail;
    @FXML
    TextField sperre_TextFeld_detail;
    @FXML
    TextField windowsKennung_TextFeld_detail;

    @FXML
    public void openNewPersonTab(Person per) {
        try {
            //System.out.println(per.getName());
            FXMLLoader loader =new FXMLLoader(getClass().getResource("/admintool/ui/stammdaten/personen/personen_detail.fxml"));

            TabPane tp = AdminTool.getRootlayoutPane();
            Tab newTab = new Tab(per.getName());
            newTab.setContent(loader.load());
            tp.getTabs().add(newTab);
            tp.getSelectionModel().select(newTab);



            personList.add(per);

            System.out.println(per.getPersonId());

            personTable.setItems(personList);

            Personen_detailController controller = loader.<Personen_detailController>getController();
            controller.initData(per);

        } catch (IOException ex) {
            Logger.getLogger(BenutzerSucheController.class.getName()).log(Level.SEVERE, null, ex);
            ExceptionDialog dia = new ExceptionDialog(Alert.AlertType.ERROR, ex);

        }
    }

    @FXML
    private void initData(Person per) {
        this.per = per;

        this.name_TextFeld_detail.setText(per.getName());
        this.land_TextFeld_detail.setText(per.getLand());

        this.personId_TextFeld_detail.setText(per.getPersonId().toString());
        this.sperre_TextFeld_detail.setText(per.getSperre().toString());
        this.windowsKennung_TextFeld_detail.setText(per.getOsKennung());

        //Erste Spalte                
       /* TableColumn vertragspartnerColumn = new TableColumn();
        vertragspartnerColumn.setText("Vertragspartner");
        vertragspartnerColumn.setMinWidth(50);
        vertragspartnerColumn.setCellValueFactory(new PropertyValueFactory("vertragspartner"));
        personTable.getColumns().add(vertragspartnerColumn);*/

        //Erste Spalte                
        TableColumn personId = new TableColumn();
        personId.setText("Person_ID");
        personId.setMinWidth(50);
        personId.setCellValueFactory(new PropertyValueFactory("personId"));
        personTable.getColumns().add(personId);
    }

}

the error appears in line 69 (personTable.setItems(personList);).

and at least the error:

Exception in thread "JavaFX Application Thread" java.lang.NullPointerException
at dummy.dummy.dummy.personen.Personen_detailController.openNewPersonTab(Personen_detailController.java:69)
at dummy.dummy.dummy.personen.PersonenController$1$1$1.handle(PersonenController.java:196)
at dummy.dummy.dummy.personen.PersonenController$1$1$1.handle(PersonenController.java:188)
at com.sun.javafx.event.CompositeEventHandler.dispatchBubblingEvent(CompositeEventHandler.java:86)
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.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.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.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.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:49)
at javafx.event.Event.fireEvent(Event.java:198)
at javafx.scene.Node.fireEvent(Node.java:8411)
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.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.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.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.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$MouseHandler.process(Scene.java:3757)
at javafx.scene.Scene$MouseHandler.access$1500(Scene.java:3485)
at javafx.scene.Scene.impl_processMouseEvent(Scene.java:1762)
at javafx.scene.Scene$ScenePeerListener.mouseEvent(Scene.java:2494)
at com.sun.javafx.tk.quantum.GlassViewEventHandler$MouseEventNotification.run(GlassViewEventHandler.java:380)
at com.sun.javafx.tk.quantum.GlassViewEventHandler$MouseEventNotification.run(GlassViewEventHandler.java:294)
at java.security.AccessController.doPrivileged(Native Method)
at com.sun.javafx.tk.quantum.GlassViewEventHandler.lambda$handleMouseEvent$354(GlassViewEventHandler.java:416)
at com.sun.javafx.tk.quantum.QuantumToolkit.runWithoutRenderLock(QuantumToolkit.java:389)
at com.sun.javafx.tk.quantum.GlassViewEventHandler.handleMouseEvent(GlassViewEventHandler.java:415)
at com.sun.glass.ui.View.handleMouseEvent(View.java:555)
at com.sun.glass.ui.View.notifyMouse(View.java:937)
at com.sun.glass.ui.win.WinApplication._runLoop(Native Method)
at com.sun.glass.ui.win.WinApplication.lambda$null$148(WinApplication.java:191)
at java.lang.Thread.run(Thread.java:745)

personen_detail.fxml:

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

<?import java.net.URL?>
<?import javafx.scene.control.Label?>
<?import javafx.scene.control.SplitPane?>
<?import javafx.scene.control.Tab?>
<?import javafx.scene.control.TabPane?>
<?import javafx.scene.control.TableView?>
<?import javafx.scene.control.TextField?>
<?import javafx.scene.layout.AnchorPane?>

<AnchorPane id="AnchorPane" prefHeight="882.0" prefWidth="1294.0" styleClass="mainFxmlClass" xmlns="http://javafx.com/javafx/8.0.60" xmlns:fx="http://javafx.com/fxml/1" fx:controller="admintool.ui.stammdaten.personen.Personen_detailController">
    <stylesheets>
        <URL value="@personen.css" />
    </stylesheets>
   <children>
      <TabPane fx:id="tabPane" prefHeight="882.0" prefWidth="1294.0" tabClosingPolicy="UNAVAILABLE" AnchorPane.bottomAnchor="0.0" AnchorPane.leftAnchor="0.0" AnchorPane.rightAnchor="0.0" AnchorPane.topAnchor="0.0">
        <tabs>
          <Tab closable="false" text="Details">
            <content>
              <AnchorPane minHeight="0.0" minWidth="0.0" prefHeight="180.0" prefWidth="200.0">
                     <children>
                        <SplitPane dividerPositions="0.2291421856639248" layoutX="151.0" layoutY="82.0" orientation="VERTICAL" prefHeight="853.0" prefWidth="1294.0" AnchorPane.bottomAnchor="0.0" AnchorPane.leftAnchor="0.0" AnchorPane.rightAnchor="0.0" AnchorPane.topAnchor="0.0">
                          <items>
                            <AnchorPane minHeight="0.0" minWidth="0.0" prefHeight="100.0" prefWidth="160.0">
                                 <children>
                                    <Label layoutX="14.0" layoutY="14.0" text="Name:" />
                                    <Label layoutX="566.0" layoutY="49.0" text="Sperre:" />
                                    <Label layoutX="547.0" layoutY="14.0" text="Person_ID:" />
                                    <TextField fx:id="name_TextFeld_detail" layoutX="66.0" layoutY="10.0" prefHeight="25.0" prefWidth="186.0" />
                                    <Label layoutX="20.0" layoutY="49.0" text="Land:" />
                                    <TextField fx:id="land_TextFeld_detail" layoutX="66.0" layoutY="45.0" prefHeight="25.0" prefWidth="186.0" />
                                    <TextField fx:id="personId_TextFeld_detail" layoutX="620.0" layoutY="10.0" />
                                    <Label layoutX="500.0" layoutY="88.0" text="Windows Kennung:" />
                                    <TextField fx:id="sperre_TextFeld_detail" layoutX="620.0" layoutY="45.0" />
                                    <TextField fx:id="windowsKennung_TextFeld_detail" layoutX="620.0" layoutY="84.0" />
                                 </children>
                              </AnchorPane>
                            <AnchorPane minHeight="0.0" minWidth="0.0" prefHeight="100.0" prefWidth="160.0">
                                 <children>
                                    <TableView fx:id="personTable" prefHeight="709.0" prefWidth="1294.0" />
                                 </children>
                              </AnchorPane>
                          </items>
                        </SplitPane>
                     </children>
                  </AnchorPane>
            </content>
          </Tab>
        </tabs>
      </TabPane>
   </children>
</AnchorPane>

if you need anything to help me, please let me know. Thank you all.

Possible duplicate of [What is a NullPointerException, and how do I fix it?](http://stackoverflow.com/questions/218384/what-is-a-nullpointerexception-and-how-do-i-fix-it) — OH GOD SPIDERS, Nov 17 '16 at 12:16
Can you post the FXML file that uses `Personen_detailController` as its controller class? The only possibility here is that `personTable` is null, so maybe the `fx:id` in that FXML file is wrong. — James_D, Nov 17 '16 at 12:16
@911DidBush While that post is probably useful for the OP, none of the answers there address fields that are initialized via injection from a framework; so there's really no help there for "why is `personTable` null?". — James_D, Nov 17 '16 at 12:18
@Xplosio Please [edit] the question to include additional information. Do not post additional information as an "answer". — James_D, Nov 17 '16 at 12:21
I deleted the anwere and added it in the original Post. Do you need anything else? — Xplosio, Nov 17 '16 at 12:23
You really need to post a [mcve], posting your full code with hundreds of lines... not the best approch — AxelH, Nov 17 '16 at 12:27
the [What is a NullPointerException, and how do I fix it?](http://stackoverflow.com/questions/218384/what-is-a-nullpointerexception-and-how-do-i-fix-it) is not the solution, because in my `list` is really an object I checked it `personList.get(0).getPersonId()` — Xplosio, Nov 17 '16 at 12:37
@Xplosio But I guess you didn't check that `personTable` wasn't null... — James_D, Nov 17 '16 at 12:38
@James_D isn't `personTable` null until I set the Item `personList`? — Xplosio, Nov 17 '16 at 12:42
Any reference is null until it is set to something non-null. You are expecting the `FXMLLoader` to set `personTable` to a `TableView` instance (since you annotate it `@FXML`). That won't work, as explained in the answer. — James_D, Nov 17 '16 at 12:44
@James_D That is true. But the question could have been made a lot clearer by asking "why isn't my injection working" or something similar. The fact that the asker didn't formulate it like that suggests that he did not really know what NPEs are and realize that his `personTable` was null. — OH GOD SPIDERS, Nov 17 '16 at 13:06
@911DidBush That's a fair point (which is reinforced by subsequent comments). While it's likely true that the OP doesn't understand what a NPE is, and your dup is helpful in that regard, the actual problem presented here is that (s)he doesn't understand what injection is. What happens from the OP's perspective when questions like this are marked as dups of the NPE question is that they then initialize the injected field. Now the NPE goes away, so that issue is "solved", but it still doesn't work, so they think something else is wrong - when in fact the underlying issue was never fixed. — James_D, Nov 17 '16 at 13:27

score 1 · Accepted Answer · edited May 23 '17 at 12:24

Fields that are initialized via @FXML injection in a controller are initialized by the FXMLLoader when the corresponding FXML file is loaded.

In your code you are creating an instance of the controller class yourself:

Personen_detailController detailController = new Personen_detailController();

Since detailController is not created by the FXMLLoader while the FXML is loaded, the @FXML-injected fields (such as personTable) will not be injected, and will remain null. Hence the null pointer exception. (In other words, detailController is not actually a controller, it is just an object that happens to be the same class as the controller for one of the FMXL files.)

You haven't posted enough code to give a complete response, but you need to get the controller from the FXMLLoader after the FXML file is loaded:

FXMLLoader loader = new FXMLLoader(getClass().getResource("path/to/fxml/file"));
Parent root = loader.load();
// display root in UI
Person_detailController detailController = loader.getController();

and then arrange for the detailController to be passed to the PersonenController instance that is similarly retrieved from its FXMLLoader.

As an alternative, consider using a MVC approach (e.g. Applying MVC With JavaFx), so both controllers have access to a shared model.

Thank you very much. You Helped me a lot :) – Xplosio Nov 17 '16 at 13:00 — Xplosio, Nov 17 '16 at 13:00

Java NullPointerException TavleView.setItem(FXCollections.observableArrayList())

1 Answers1