JavaFX异常加载FXML文件

Question

我一直在使用桌面应用程序，我需要使用JavaFX。我在使用Scene Builder构建的eclipse上的JavaFX项目中创建了各种FXML文件。加载任何FXML文件都没有问题，除了这个讨厌的文件（FXMLImgList.fxml）。

主要思想是按下按钮时会出现一个新窗口。这是我的代码，用于该按钮的事件处理程序：

@FXML
private void handleOnActionButtonImg(ActionEvent e) throws MalformedURLException, URISyntaxException
{
    FXMLLoader loader = new FXMLLoader(getClass().getResource("/res/FXMLImgList.fxml").toURI().toURL());
    VBox root = null;
    try {
        root = (VBox) loader.load(); // ERROR LOADING HERE
    } catch (IOException e1) {
        e1.printStackTrace();
    }

    ImgListController ilc = loader.getController();
    ilc.init(imgUrl);

    Scene scene = new Scene(root);
    Stage stage = new Stage();
    stage.initModality(Modality.WINDOW_MODAL);
    stage.initOwner((Stage) vBox.getScene().getWindow());
    stage.setScene(scene);
    stage.setResizable(false);
    stage.setTitle("Elegir imagen");
    stage.show();
}

包浏览器中的项目如下所示：

  

https://image.ibb.co/ihGMoS/Capture.png（无法发布图片）

我从try-catch块中得到了这个异常：

javafx.fxml.LoadException:
/C:/Users/Ximo/Desktop/UNI/2017-2018%20(UPV)/IPC/EclipseWorkspaceIPC/PL03_Ej2/bin/res/FXMLImgList.fxml

    at javafx.fxml.FXMLLoader.constructLoadException(FXMLLoader.java:2601)
    at javafx.fxml.FXMLLoader.loadImpl(FXMLLoader.java:2579)
    at javafx.fxml.FXMLLoader.loadImpl(FXMLLoader.java:2441)
    at javafx.fxml.FXMLLoader.load(FXMLLoader.java:2409)
    at application.VentanaController.handleOnActionButtonImg(VentanaController.java:108)
    at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
    at sun.reflect.NativeMethodAccessorImpl.invoke(Unknown Source)
    at sun.reflect.DelegatingMethodAccessorImpl.invoke(Unknown Source)
    at java.lang.reflect.Method.invoke(Unknown Source)
    at sun.reflect.misc.Trampoline.invoke(Unknown Source)
    at sun.reflect.GeneratedMethodAccessor1.invoke(Unknown Source)
    at sun.reflect.DelegatingMethodAccessorImpl.invoke(Unknown Source)
    at java.lang.reflect.Method.invoke(Unknown Source)
    at sun.reflect.misc.MethodUtil.invoke(Unknown Source)
    at javafx.fxml.FXMLLoader$MethodHandler.invoke(FXMLLoader.java:1769)
    at javafx.fxml.FXMLLoader$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:8413)
    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$MouseEventNotification.run(GlassViewEventHandler.java:381)
    at com.sun.javafx.tk.quantum.GlassViewEventHandler$MouseEventNotification.run(GlassViewEventHandler.java:295)
    at java.security.AccessController.doPrivileged(Native Method)
    at com.sun.javafx.tk.quantum.GlassViewEventHandler.lambda$handleMouseEvent$353(GlassViewEventHandler.java:417)
    at com.sun.javafx.tk.quantum.QuantumToolkit.runWithoutRenderLock(QuantumToolkit.java:389)
    at com.sun.javafx.tk.quantum.GlassViewEventHandler.handleMouseEvent(GlassViewEventHandler.java:416)
    at com.sun.glass.ui.View.handleMouseEvent(View.java:555)
    at com.sun.glass.ui.View.notifyMouse(View.java:937)
    at com.sun.glass.ui.win.WinApplication._runLoop(Native Method)
    at com.sun.glass.ui.win.WinApplication.lambda$null$147(WinApplication.java:177)
    at java.lang.Thread.run(Unknown Source)
Caused by: java.lang.IllegalArgumentException: Invalid URL: unknown protocol: c
    at javafx.scene.image.Image.validateUrl(Image.java:1121)
    at javafx.scene.image.Image.<init>(Image.java:659)
    at application.ImgListController.initialize(ImgListController.java:64)
    at javafx.fxml.FXMLLoader.loadImpl(FXMLLoader.java:2548)
    ... 61 more
Caused by: java.net.MalformedURLException: unknown protocol: c
    at java.net.URL.<init>(Unknown Source)
    at java.net.URL.<init>(Unknown Source)
    at java.net.URL.<init>(Unknown Source)
    at javafx.scene.image.Image.validateUrl(Image.java:1115)
    ... 64 more
Exception in thread "JavaFX Application Thread" java.lang.RuntimeException: java.lang.reflect.InvocationTargetException
    at javafx.fxml.FXMLLoader$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:8413)
    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$MouseEventNotification.run(GlassViewEventHandler.java:381)
    at com.sun.javafx.tk.quantum.GlassViewEventHandler$MouseEventNotification.run(GlassViewEventHandler.java:295)
    at java.security.AccessController.doPrivileged(Native Method)
    at com.sun.javafx.tk.quantum.GlassViewEventHandler.lambda$handleMouseEvent$353(GlassViewEventHandler.java:417)
    at com.sun.javafx.tk.quantum.QuantumToolkit.runWithoutRenderLock(QuantumToolkit.java:389)
    at com.sun.javafx.tk.quantum.GlassViewEventHandler.handleMouseEvent(GlassViewEventHandler.java:416)
    at com.sun.glass.ui.View.handleMouseEvent(View.java:555)
    at com.sun.glass.ui.View.notifyMouse(View.java:937)
    at com.sun.glass.ui.win.WinApplication._runLoop(Native Method)
    at com.sun.glass.ui.win.WinApplication.lambda$null$147(WinApplication.java:177)
    at java.lang.Thread.run(Unknown Source)
Caused by: java.lang.reflect.InvocationTargetException
    at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
    at sun.reflect.NativeMethodAccessorImpl.invoke(Unknown Source)
    at sun.reflect.DelegatingMethodAccessorImpl.invoke(Unknown Source)
    at java.lang.reflect.Method.invoke(Unknown Source)
    at sun.reflect.misc.Trampoline.invoke(Unknown Source)
    at sun.reflect.GeneratedMethodAccessor1.invoke(Unknown Source)
    at sun.reflect.DelegatingMethodAccessorImpl.invoke(Unknown Source)
    at java.lang.reflect.Method.invoke(Unknown Source)
    at sun.reflect.misc.MethodUtil.invoke(Unknown Source)
    at javafx.fxml.FXMLLoader$MethodHandler.invoke(FXMLLoader.java:1769)
    ... 48 more
Caused by: java.lang.NullPointerException: Root cannot be null
    at javafx.scene.Scene.<init>(Scene.java:336)
    at javafx.scene.Scene.<init>(Scene.java:194)
    at application.VentanaController.handleOnActionButtonImg(VentanaController.java:116)
    ... 58 more

什么甚至更奇怪，其余的FXML文件加载得很好，例如这个：

@FXML
private void handleOnActionButtonMod(ActionEvent event) 
{
    FXMLLoader loader = new FXMLLoader(getClass().getResource("/res/FXMLVentana.fxml"));
    VBox root = null;
    try {
        root = (VBox) loader.load(); // NO ERROR LOADING HERE
    } catch (IOException e) {
        e.printStackTrace();
    }
    VentanaController vac = loader.getController();
    vac.init(observablePersonData, table.getSelectionModel().selectedIndexProperty().getValue());
    Scene scene = new Scene(root);
    Stage stage = new Stage();
    stage.initModality(Modality.WINDOW_MODAL);
    stage.initOwner(this.stage);
    stage.setScene(scene);
    stage.setResizable(false);
    stage.setTitle("Modificar");
    stage.show();
}

这个事件处理程序背后的想法几乎相同，按下按钮 - ＆gt;窗口打开并且工作得很好。我已经尝试了许多这样的功能，比如编辑返回的网址，但似乎没有任何效果。

我已注意到第67行的消息：

  

引起：java.lang.IllegalArgumentException：无效的URL：未知   协议：c

然而结果是：

    System.out.println(getClass().getResource("/res/FXMLVentana.fxml"));
    System.out.println(getClass().getResource("/res/FXMLImgList.fxml"));

输出：

  

文件：/ C：/用户/细末/桌面/ UNI / 2017至2018年20％（UPV）/IPC/EclipseWorkspaceIPC/PL03_Ej2/bin/res/FXMLVentana.fxml

     

文件：/ C：/用户/细末/桌面/ UNI / 2017至2018年20％（UPV）/IPC/EclipseWorkspaceIPC/PL03_Ej2/bin/res/FXMLImgList.fxml

这里是FXMLImgList.fxml的代码：     

<?import javafx.geometry.Insets?>
<?import javafx.scene.control.Button?>
<?import javafx.scene.layout.HBox?>
<?import javafx.scene.layout.VBox?>

<VBox fx:id="root" maxHeight="-Infinity" maxWidth="-Infinity" minHeight="-Infinity" minWidth="-Infinity" spacing="12.0" xmlns="        http://javafx.com/javafx/8.0.151" xmlns:fx="http://javafx.com/fxml/1" fx:controller="application.ImgListController">
   <children>
      <HBox alignment="CENTER_RIGHT" spacing="12.0">
         <children>
            <Button fx:id="cancelar" mnemonicParsing="false" onAction="#handleOnActionButtonCancelar" text="Cancelar" />
            <Button fx:id="salvar" mnemonicParsing="false" onAction="#handleOnActionButtonSalvar" text="Salvar" />
         </children>
         <VBox.margin>
            <Insets />
         </VBox.margin>
      </HBox>
   </children>
   <padding>
      <Insets bottom="12.0" left="12.0" right="12.0" top="12.0" />
   </padding>
</VBox>

这里有FXMLVentana.fxml：

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

<?import javafx.geometry.Insets?>
<?import javafx.scene.control.Button?>
<?import javafx.scene.control.Label?>
<?import javafx.scene.control.TextField?>
<?import javafx.scene.image.ImageView?>
<?import javafx.scene.layout.HBox?>
<?import javafx.scene.layout.VBox?>

<VBox fx:id="vBox" maxHeight="-Infinity" maxWidth="-Infinity" minHeight="-Infinity" minWidth="-Infinity" spacing="12.0" xmlns="http://javafx.com/javafx/8.0.151" xmlns:fx="http://javafx.com/fxml/1" fx:controller="application.VentanaController">
   <children>
      <HBox alignment="CENTER" spacing="30.0">
         <children>
            <Label prefHeight="17.0" prefWidth="53.0" text="DNI" />
            <TextField fx:id="dni" />
         </children>
      </HBox>
      <HBox alignment="CENTER" spacing="30.0">
         <children>
            <Label prefHeight="17.0" prefWidth="53.0" text="Nombre" />
            <TextField fx:id="nombre" />
         </children>
      </HBox>
      <HBox alignment="CENTER" spacing="30.0">
         <children>
            <Label prefHeight="17.0" prefWidth="52.0" text="Apellidos" />
            <TextField fx:id="apellidos" />
         </children>
      </HBox>
      <HBox alignment="CENTER" spacing="30.0">
         <children>
            <Label prefHeight="17.0" prefWidth="52.0" text="Ciudad" />
            <TextField fx:id="city" />
         </children>
      </HBox>
      <HBox alignment="CENTER" spacing="30.0">
         <children>
            <Label prefHeight="17.0" prefWidth="52.0" text="Provincia" />
            <TextField fx:id="province" />
         </children>
      </HBox>
      <HBox alignment="CENTER" spacing="12.0">
         <children>
            <ImageView fx:id="imgView" fitHeight="80.0" fitWidth="80.0" onMouseClicked="#handleImgMouseClick" pickOnBounds="true" preserveRatio    ="true" />
        <Button     fx:id="buttonImg" mnemonicParsing="false" onAction="#handleOnActionButtonImg" text="Imagen" />
     </children    >
  </HBox    >
  <    HBox alignment="CENTER_RIGHT" spacing="12.0">
         <children>
            <Button fx:id="buttonCancelar" mnemonicParsing="false" onAction="#handleOnActionButtonCancelar" text="Cancelar" />
            <Button fx:id="buttonAction" mnemonicParsing="false" onAction="#handleOnActionButtonAction" text="Salvar" />
         </children>
      </HBox>
   </children>
   <padding>
      <Insets bottom="12.0" left="30.0" right="30.0" top="12.0" />
   </padding>
</VBox>

总而言之，我所有的想法都没有，我找不到任何东西似乎解决了这个问题。感谢任何帮助，谢谢！

Answer 1

在你的堆栈跟踪中有2个例外。

当您尝试将root传递给Scene的构造函数时，最后一个表示Image为空。这是因为加载fxml失败了。这不是因为fxml网址无效，而是因为ImgListController.initialize方法中创建的File值不是URL作为构造函数参数。可能你传递了一个绝对文件路径。

您可以使用Path或File f = ... URL url = f.toURI().toURL(); Image img = new Image(url.toExternalForm()); 类来获取文件的网址：

{{1}}

注意：如果发生异常，您不应该只是继续使用您的逻辑，并且该方法的其余部分依赖于try-block来完成而没有异常。这样你就得到2个例外，而不只是一个。

替代方案是：

• 重新抛出

  抛出新的IllegalStateException（＆＃34;这不应该发生＆＃34;，e1）;

• 向用户显示错误/记录错误后返回。
• 等...