JavaFX異なるウィンドウで2つのコントローラ間で通信を行う方法

Question

2つのコントローラに通信する際に問題があります。 これらのうちの1つはMainPanelControllerであり、2つ目はAddUserControllerです。 AddUserControllerでUserNameOkButtonをクリックした後、mainControl.getTopPanelController（）。getUserSplitMenuButton（）で新しい項目を作成します。 しかし、私はこの行に誤りがあります。

package simplygoals.control; 
import simplygoals.model.*; 
import simplygoals.control.AddUserController; 
import java.util.ArrayList; 
import javafx.scene.control.MenuItem; 
import java.net.URL; 
import java.sql.SQLException; 
import java.util.ResourceBundle; 
import simplygoals.model.MySQLAccess; 
import javafx.fxml.FXML; 
import javafx.fxml.Initializable; 
import javafx.scene.control.Button; 
import javafx.scene.control.SplitMenuButton; 

import javafx.event.ActionEvent; 
import javafx.event.EventHandler; 
import javafx.fxml.FXMLLoader; 
import javafx.scene.Parent; 
import javafx.scene.Scene; 
import javafx.stage.Modality; 
import javafx.stage.Stage; 
import javafx.stage.StageStyle; 

public class MainPanelController extends MainController implements Initializable { 


    @FXML 
    private AddUserController addUserController; 

    @FXML 
    private TopPanelController topPanelController; 

    @FXML 
    private MenuPanelController menuPanelController; 

    @FXML 
    private LeftPanelTimeModeController leftPanelTimeModeController; 

    @FXML 
    private CenterPanelTableController centerPanelTableController; 


    @Override 
    public void initialize(URL location, ResourceBundle resources) { 
     //if there is no database create it, otherwise not 

     getAppModel().getMySQL().createDatabase(); 
     getAppModel().copyUsersfromMySqlToAllUsers(); 

     createNewUserTopPanel(); 
     showUsersTopPanel(); 



    } 
    public void showUsersTopPanel(){ 

     SplitMenuButton splitMenuButton = getTopPanelController().getUserSplitMenuButton(); 


         for(String t:getAppModel().getAllUsers().getUsersString()){ 

          final MenuItem menuItem = new MenuItem(t); 
          menuItem.setText(t); 
          splitMenuButton.getItems().add(menuItem); 

         } 

    } 
    public void createNewUserTopPanel(){ 
     MenuItem menuItem = getTopPanelController().getUserSplitMenuItem(); 
     menuItem.setOnAction(new EventHandler<ActionEvent>(){ 

       public void handle(ActionEvent event) { 
          try { 
       FXMLLoader fxmlLoader = new FXMLLoader(getClass().getResource("/simplygoals/view/AddUser.fxml")); 
         Parent root1 = (Parent) fxmlLoader.load(); 
         Stage stage = new Stage(); 
         stage.setScene(new Scene(root1)); 
         stage.show(); 
       } catch(Exception e) { 
        e.printStackTrace(); 
        } 
       } 
     }); 
    } 
    public TopPanelController getTopPanelController() { 
     return topPanelController; 
    } 
} 

第二のコントローラがあります：

package simplygoals.control; 
import java.net.URL; 
import javafx.fxml.Initializable; 
import java.util.ResourceBundle; 
import javafx.fxml.FXML; 
import javafx.scene.control.Button; 
import javafx.scene.control.MenuItem; 
import javafx.scene.control.SplitMenuButton; 
import javafx.scene.control.TextField; 
import javafx.scene.layout.AnchorPane; 
import simplygoals.control.MainPanelController; 
public class AddUserController extends MainController implements Initializable { 

    private MainPanelController mainControl; 

    @FXML 
    private Button UserNameOkButton; 

    @FXML 
    private AnchorPane AddUserAnchor; 

    @FXML 
    private TextField UserNameTextField; 

    @Override 
    public void initialize(URL arg0, ResourceBundle arg1) { 
     UserNameOkButton.setOnAction(x->{ 
      getAppModel().addNewUserToMySql(UserNameTextField.getText()); 
      getAppModel().copyUsersfromMySqlToAllUsers(); 
      SplitMenuButton splitMenuButton = mainControl.getTopPanelController().getUserSplitMenuButton(); 
      splitMenuButton.getItems().clear(); 
      for(String t:getAppModel().getAllUsers().getUsersString()){ 
       final MenuItem menuItem = new MenuItem(t); 
       menuItem.setText(t); 
       splitMenuButton.getItems().add(menuItem); 
      } 
     }); 

    } 

AddUserControllerは新しいウィンドウでコントローラです。そこに私は1つのテキストフィールドとOKボタンがあります。私はこの後、menuplitbuttonの新しい項目をクリックして作成したいのですが、MainPanelControllerを使用する必要があります。 異なるウィンドウで2つのコントローラを通信する方法は？ ありがとうございます。ここで エラー：

Exception in thread "JavaFX Application Thread" java.lang.NullPointerException 
    at simplygoals.control.AddUserController.lambda$0(AddUserController.java:30) 
    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.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.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(Unknown Source) 

Answer 1

あなたはどこにでもmainControlを初期化していません。あなたがロードするとき

がそれを初期化するためにAddUserControllerでsetMainControl()方法を定義し、それを呼び出すAddUser.fxml：

menuItem.setOnAction(event -> { 
    try { 
     FXMLLoader fxmlLoader = new FXMLLoader(getClass().getResource("/simplygoals/view/AddUser.fxml")); 
     Parent root1 = (Parent) fxmlLoader.load(); 
     Stage stage = new Stage(); 
     stage.setScene(new Scene(root1)); 

     AddUserController addUserController = fxmlLoader.getController(); 
     addUserController.setMainControl(this); 

     stage.show(); 
    } catch(Exception e) { 
     e.printStackTrace(); 
    } 
});