Gluon Afterburner getPresenter() 仅返回 NoSuchElementException：不存在任何值

Question

我使用 Glisten Afterburner (v2.1.0) 从 Gluon Start 生成一个简单的应用程序。这会生成三个类，其中两个是 Main 和 AppViewManager，使用 glisten.afterburner AppView 和 AppViewRegistry。我向生成的代码添加了一个附加视图（“其他”），并向 AppViewManager 添加了方法以获取与视图关联的 Presenter。

生成的 Main 类如下所示，我在其中添加了获取 Presenters 的静态调用： getMainPresenter() 和 getOtherPresenter()：

public class Main extends Application {
    private final AppManager appManager = AppManager.initialize(this::postInit);

    @Override
    public void init() {
        AppViewManager.registerViewsAndDrawer();
    }

    @Override
    public void start(Stage stage) {
        appManager.start(stage);
    }

    private void postInit(Scene scene) {
    :
       // Get Main Presenter
       AppViewManager.getMainPresenter();
       // Get Other Presenter
       AppViewManager.getOtherPresenter();
    }
    :
}

AppViewManager 如下所示，我添加了附加视图（“其他”）并添加了获取 Presenters 的方法与视图相关联。在注册视图时，我添加了一些输出来查看发生了什么：

public class AppViewManager {
    private static final AppViewRegistry REGISTRY = new AppViewRegistry();

    public static final AppView MAIN_VIEW = view("Home", MainPresenter.class, MaterialDesignIcon.HOME, SHOW_IN_DRAWER, HOME_VIEW, SKIP_VIEW_STACK);
    public static final AppView OTHER_VIEW = view("Other", OtherPresenter.class, MaterialDesignIcon.NOTE, SHOW_IN_DRAWER, SKIP_VIEW_STACK);

    private static AppView view(String title, Class<?> presenterClass, MaterialDesignIcon menuIcon, AppView.Flag... flags ) {
        return REGISTRY.createView(name(presenterClass), title, presenterClass, menuIcon, flags);
    }

    private static String name(Class<?> presenterClass) {
        return presenterClass.getSimpleName().toUpperCase(Locale.ROOT).replace("PRESENTER", "");
    }

    public static void registerViewsAndDrawer()
    {
        for (AppView view : REGISTRY.getViews())
        {
            // What's in the REGISTRY?
            System.out.println("==> View: " +view.getId()+ ", Presenter: " +view.getPresenterClass().getCanonicalName());
            // Not sure what the following does, the javadoc is blank!
            view.registerView();
        }
    :
    }
    
    /**
     * Get MainPresenter.
     * See: .../AppViewRegistry.html#getPresenter(com.gluonhq.charm.glisten.afterburner.AppView)
     */
    public static void getMainPresenter()
    {
        MainPresenter mp = (MainPresenter)MAIN_VIEW.getPresenter().get();
        System.out.println("..Presenter..> " +mp.toString());
    }
    
    public static void getOtherPresenter()
    {
        OtherPresenter op = (OtherPresenter)OTHER_VIEW.getPresenter().get();
        System.out.println("..OtherPresenter..> " +op.toString());
    }
}

OtherPresenter 是一个简单的声明：

public class OtherPresenter {
    public void initialize() {}
}

OtherPresenter FXML 是：

<View fx:id="other" maxHeight="-Infinity" maxWidth="-Infinity" minHeight="-Infinity" minWidth="-Infinity" xmlns="http://javafx.com/javafx/11.0.1" xmlns:fx="http://javafx.com/fxml/1" fx:controller="com.runtheworld.sample.OtherPresenter">
    <center>
        <VBox styleClass="box">
            <children>
                <Label text="Other!" />
            </children>
        </VBox>
    </center>
</View>

REGISTRY 输出中的内容符合预期（除了我期望的是“HOME_VIEW”而不是“home”）：

==> View: home, Presenter: com.runtheworld.sample.MainPresenter
==> View: OTHER_VIEW, Presenter: com.runtheworld.sample.OtherPresenter

但无论我在哪里进行 getOtherPresenter() 调用，它都会返回：“Caused by: java.util.NoSuchElementException: No value present”。然而， getMainPresenter() 调用是有效的。事实上，该应用程序可以正常运行，显示 OtherPresenter（显示“其他！”），但仍然抛出“无值”。

为什么 Main 工作但其他不工作，是否有一些我错过的设置/初始化？

这是所有输出：

==> View: home, Presenter: com.runtheworld.sample.MainPresenter
==> View: OTHER_VIEW, Presenter: com.runtheworld.sample.OtherPresenter
Apr 03, 2022 11:24:16 AM com.gluonhq.attach.util.Platform <clinit>
INFO: [Gluon Attach] System Property javafx.platform is not defined. Platform will be set to Platform.DESKTOP
..MainPresenter..> com.runtheworld.sample.MainPresenter@686bbb76
java.util.NoSuchElementException: No value present
    at java.base/java.util.Optional.get(Optional.java:143)
    at com.runtheworld.sample.AppViewManager.getOtherPresenter(AppViewManager.java:54)
    at com.runtheworld.sample.Main.postInit(Main.java:41)
    at com.gluonhq.charm.glisten.application.AppManager.continueInit(AppManager.java:328)
    at com.gluonhq.charm.glisten.application.AppManager.start(AppManager.java:288)
    at com.runtheworld.sample.Main.start(Main.java:24)
    at javafx.graphics/com.sun.javafx.application.LauncherImpl.lambda$launchApplication1$9(LauncherImpl.java:847)
    at javafx.graphics/com.sun.javafx.application.PlatformImpl.lambda$runAndWait$12(PlatformImpl.java:484)
    at javafx.graphics/com.sun.javafx.application.PlatformImpl.lambda$runLater$10(PlatformImpl.java:457)
    at java.base/java.security.AccessController.doPrivileged(AccessController.java:399)
    at javafx.graphics/com.sun.javafx.application.PlatformImpl.lambda$runLater$11(PlatformImpl.java:456)
    at javafx.graphics/com.sun.glass.ui.InvokeLaterDispatcher$Future.run(InvokeLaterDispatcher.java:96)
    at javafx.graphics/com.sun.glass.ui.gtk.GtkApplication._runLoop(Native Method)
    at javafx.graphics/com.sun.glass.ui.gtk.GtkApplication.lambda$runLoop$11(GtkApplication.java:290)
    at java.base/java.lang.Thread.run(Thread.java:833)

编辑： 我决定避开 afterburner，简单地构建一个视图，如下所示：

public class OtherView {
    public static final String OTHER_VIEW = "OTHER_VIEW";
    
    public AbstractMap.SimpleEntry<String,AbstractMap.SimpleEntry<View,Presenter>> getViewController() {
        try {
            FXMLLoader f = new FXMLLoader(OtherView.class.getResource("/path/to/other.fxml"), ResourceBundle.getBundle("path.to.other"));
            View view = f.load();
            
            OtherPresenter controller = f.getController();
            return new AbstractMap.SimpleEntry(OTHER_VIEW,new AbstractMap.SimpleEntry(view,controller));
        } catch (IOException e) {
            e.printStackTrace();
            return null;
        }
    }
}

视图和控制器在 FXML 中定义，这将视图名称与视图及其关联的控制器联系起来。 getViewController() 是从 Main.init() 调用的。