JavaFX:线程 “JavaFX Application Thread” java.lang.RuntimeException 中出现异常:java.lang.reflect.InitationTargetException

Question

我正在开发 Java FX 项目我创建了两个 FXML 文件，我想加载另一个 Pane 来解决主要问题，即边框 Pane 。我想将另一个 Pane 加载到边框 Pane 中心区域!

这是我的项目的入口点，它是一个 Java 文件

package javafxapplication8;

    import java.io.IOException;
    import javafx.application.Application;
    import javafx.fxml.FXML;
    import javafx.fxml.FXMLLoader;
    import javafx.scene.Parent;
    import javafx.scene.Scene;
    import javafx.scene.input.MouseEvent;
    import javafx.scene.layout.BorderPane;
    import javafx.stage.Stage;

    /**
     *
     * @author Anu
     */
    public class JavaFXApplication8 extends Application {

        @Override
        public void start(Stage stage) throws Exception {
            Parent root = FXMLLoader.load(getClass().getResource("FXMLDocument.fxml"));
            Scene scene = new Scene(root);
            stage.setScene(scene);
            stage.show();
        }
        @FXML
        void handleButtonAction(MouseEvent event) throws IOException {
        }
        /**
         * @param args the command line arguments
         */
        public static void main(String[] args) {
            launch(args);
        }
    }

之后显示主 FXML 文件，其中显示我的边框 Pane

<?xml version="1.0" encoding="UTF-8"?>
    <?import com.jfoenix.controls.JFXButton?>
    <?import javafx.scene.layout.AnchorPane?>
    <?import javafx.scene.layout.BorderPane?>

    <AnchorPane id="AnchorPane" prefHeight="200" prefWidth="320" xmlns:fx="http://javafx.com/fxml/1" xmlns="http://javafx.com/javafx/8.0.171" 
                fx:controller="javafxapplication8.FXMLDocumentController">
       <children>
          <BorderPane fx:id="rootStage" layoutX="14.0" layoutY="-14.0" prefHeight="200.0" prefWidth="320.0" AnchorPane.bottomAnchor="0.0" AnchorPane.leftAnchor="0.0" AnchorPane.rightAnchor="0.0" AnchorPane.topAnchor="0.0">
             <left>
                <JFXButton buttonType="RAISED" 
                           onAction="#handleButtonAction"
                            text="Load Pane" BorderPane.alignment="CENTER" />
             </left>
          </BorderPane>
       </children>
    </AnchorPane>

我设置了一个按钮来显示特定 Pane 到该边框 Pane 中心区域。

<left>
   <JFXButton buttonType="RAISED" 
    onAction="#handleButtonAction"
    text="Load Pane" BorderPane.alignment="CENTER" />
</left>

这是我的边框 Pane 包含类的 Controller 类

package javafxapplication8;

    import java.io.IOException;
    import java.net.URL;
    import java.util.ResourceBundle;
    import javafx.event.ActionEvent;
    import javafx.fxml.FXML;
    import javafx.fxml.FXMLLoader;
    import javafx.fxml.Initializable;
    import javafx.scene.control.Label;
    import javafx.scene.layout.BorderPane;

    /**
     *
     * @author Anu
     */
    public class FXMLDocumentController implements Initializable {

        @FXML
        private BorderPane rootStage;

        @FXML
        private void handleButtonAction(ActionEvent event) throws IOException {
            System.out.println("Button Click");
            FXMLLoader loader = new FXMLLoader();  
            loader.setLocation(javafx.stage.Stage.class.getResource("FXML.fxml"));  

            BorderPane newScene = loader.load();  
            rootStage.setCenter(newScene);  
        }

        @Override
        public void initialize(URL url, ResourceBundle rb) {
            // TODO
            System.out.println("FXMLDocumentController");
        }    

    }

这是我想在边框 Pane 中心区域显示的 FXML 文件。

        <?xml version="1.0" encoding="UTF-8"?>
    <?import javafx.scene.control.Label?>
    <?import javafx.scene.layout.AnchorPane?>
    <?import javafx.scene.text.Font?>

    <AnchorPane id="AnchorPane" prefHeight="400.0" prefWidth="600.0" xmlns:fx="http://javafx.com/fxml/1" xmlns="http://javafx.com/javafx/8.0.171" fx:controller="javafxapplication8.FXMLController">
       <children>
          <Label layoutX="252.0" layoutY="179.0" text="Label">
             <font>
                <Font size="41.0" />
             </font>
          </Label>
       </children>
    </AnchorPane>

但是当我单击按钮时，出现了一堆错误!

Executing C:\Users\Anu\Documents\NetBeansProjects\JavaFXApplication8\dist\run922593932\JavaFXApplication8.jar using platform C:\Program Files\Java\jdk1.8.0_172\jre/bin/java
    FXMLDocumentController
    Button Click
    Exception in thread "JavaFX Application Thread" java.lang.RuntimeException: java.lang.reflect.InvocationTargetException
        at javafx.fxml.FXMLLoader$MethodHandler.invoke(FXMLLoader.java:1774)
        at javafx.fxml.FXMLLoader$ControllerMethodEventHandler.handle(FXMLLoader.java:1657)
        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$MouseEventNotification.run(GlassViewEventHandler.java:394)
        at com.sun.javafx.tk.quantum.GlassViewEventHandler$MouseEventNotification.run(GlassViewEventHandler.java:295)
        at java.security.AccessController.doPrivileged(Native Method)
        at com.sun.javafx.tk.quantum.GlassViewEventHandler.lambda$handleMouseEvent$353(GlassViewEventHandler.java:432)
        at com.sun.javafx.tk.quantum.QuantumToolkit.runWithoutRenderLock(QuantumToolkit.java:389)
        at com.sun.javafx.tk.quantum.GlassViewEventHandler.handleMouseEvent(GlassViewEventHandler.java:431)
        at com.sun.glass.ui.View.handleMouseEvent(View.java:555)
        at com.sun.glass.ui.View.notifyMouse(View.java:937)
        at com.sun.glass.ui.win.WinApplication._runLoop(Native Method)
        at com.sun.glass.ui.win.WinApplication.lambda$null$147(WinApplication.java:177)
        at java.lang.Thread.run(Thread.java:748)
    Caused by: java.lang.reflect.InvocationTargetException
        at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
        at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
        at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
        at java.lang.reflect.Method.invoke(Method.java:498)
        at sun.reflect.misc.Trampoline.invoke(MethodUtil.java:71)
        at sun.reflect.GeneratedMethodAccessor1.invoke(Unknown Source)
        at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
        at java.lang.reflect.Method.invoke(Method.java:498)
        at sun.reflect.misc.MethodUtil.invoke(MethodUtil.java:275)
        at javafx.fxml.FXMLLoader$MethodHandler.invoke(FXMLLoader.java:1769)
        ... 48 more
    Caused by: java.lang.IllegalStateException: Location is not set.
        at javafx.fxml.FXMLLoader.loadImpl(FXMLLoader.java:2434)
        at javafx.fxml.FXMLLoader.load(FXMLLoader.java:2409)
        at javafxapplication8.FXMLDocumentController.handleButtonAction(FXMLDocumentController.java:33)
        ... 58 more

我的项目结构:

有人可以告诉我我错过了什么吗？谢谢。

Answer 1

有两个原因

javafx.stage.Stage.class.getResource("FXML.fxml")

返回null，这是异常的原因:

• 不以 / 开头的资源是相对于类进行解析的，即本例中 java 正在寻找的资源是 /javafx/stage/FXML.fxml 而不是您的资源的真实位置
由于某种原因，
• Stage 似乎使用了不同的类加载器，无法解析位于 jar 中的资源。确保使用由有权访问 jar 的类加载器加载的不同类，例如使用FXMLDocumentController.class

loader.setLocation(FXMLDocumentController.class.getResource("/javafxapplication8/FXML.fxml"));

<小时/>

注意:您可能需要使用清理并构建来将新的.class文件添加到jar中。