无法加载图像获取空指针异常

Question

I am trying to add an image from the "photographs" folder into a list.我正在尝试将“照片”文件夹中的图像添加到列表中。 The list has been initialized and the relative path of the photo is correct.列表已初始化，照片的相对路径正确。 PhotographicGame is the name of the class where this method is written. PhotographyGame 是编写此方法的类的名称。 I keep on getting a null pointer exception when the method tries to "add" the image to the list.当该方法尝试将图像“添加”到列表中时，我不断收到空指针异常。 HELP!!帮助！！

I have another case in which I used this exact method and had no problems!我有另一个案例，我使用了这种确切的方法并且没有问题！

    private List<Image> populateList()
    {
        photoList.add(new Image(PhotographicGame.class.getResourceAsStream("photographs/faces/face1.jpg"), 200, 400, true, true));
        return photoList;
    }

UPDATED: Once i try to perform the above mentioned action im getting an error like:更新：一旦我尝试执行上述操作，我就会收到如下错误：

    Mar 11, 2016 2:10:53 AM brainbright.gui.gameselect.GameSelectController startGame
SEVERE: null
javafx.fxml.LoadException: 
file:/C:/Users/D/Documents/3/Industrial/new/BrainBright-master/dist/run285479268/BrainBright.jar!/brainbright/gui/facenamehouse/FaceNameHouse.fxml:85

    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.loadImpl(FXMLLoader.java:3214)
    at javafx.fxml.FXMLLoader.loadImpl(FXMLLoader.java:3175)
    at javafx.fxml.FXMLLoader.loadImpl(FXMLLoader.java:3148)
    at javafx.fxml.FXMLLoader.loadImpl(FXMLLoader.java:3124)
    at javafx.fxml.FXMLLoader.loadImpl(FXMLLoader.java:3104)
    at javafx.fxml.FXMLLoader.load(FXMLLoader.java:3097)
    at brainbright.gui.gameselect.GameSelectController.startGame(GameSelectController.java:362)
    at brainbright.gui.gameselect.GameSelectController.handleStartAction(GameSelectController.java:304)
    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:497)
    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:497)
    at sun.reflect.misc.MethodUtil.invoke(MethodUtil.java:275)
    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: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$MouseEventNotification.run(GlassViewEventHandler.java:352)
    at com.sun.javafx.tk.quantum.GlassViewEventHandler$MouseEventNotification.run(GlassViewEventHandler.java:275)
    at java.security.AccessController.doPrivileged(Native Method)
    at com.sun.javafx.tk.quantum.GlassViewEventHandler.lambda$handleMouseEvent$355(GlassViewEventHandler.java:388)
    at com.sun.javafx.tk.quantum.QuantumToolkit.runWithoutRenderLock(QuantumToolkit.java:389)
    at com.sun.javafx.tk.quantum.GlassViewEventHandler.handleMouseEvent(GlassViewEventHandler.java:387)
    at com.sun.glass.ui.View.handleMouseEvent(View.java:555)
    at com.sun.glass.ui.View.notifyMouse(View.java:937)
    at com.sun.glass.ui.win.WinApplication._runLoop(Native Method)
    at com.sun.glass.ui.win.WinApplication.lambda$null$149(WinApplication.java:191)
    at java.lang.Thread.run(Thread.java:745)
Caused by: java.lang.IllegalArgumentException: Can not set javafx.scene.layout.HBox field brainbright.gui.facenamehouse.FaceNameHouseController.faceContainer to javafx.scene.layout.VBox
    at sun.reflect.UnsafeFieldAccessorImpl.throwSetIllegalArgumentException(UnsafeFieldAccessorImpl.java:167)
    at sun.reflect.UnsafeFieldAccessorImpl.throwSetIllegalArgumentException(UnsafeFieldAccessorImpl.java:171)
    at sun.reflect.UnsafeObjectFieldAccessorImpl.set(UnsafeObjectFieldAccessorImpl.java:81)
    at java.lang.reflect.Field.set(Field.java:764)
    at javafx.fxml.FXMLLoader.injectFields(FXMLLoader.java:1163)
    at javafx.fxml.FXMLLoader.access$1600(FXMLLoader.java:103)
    at javafx.fxml.FXMLLoader$ValueElement.processValue(FXMLLoader.java:857)
    at javafx.fxml.FXMLLoader$ValueElement.processStartElement(FXMLLoader.java:751)
    at javafx.fxml.FXMLLoader.processStartElement(FXMLLoader.java:2707)
    at javafx.fxml.FXMLLoader.loadImpl(FXMLLoader.java:2527)
    ... 67 more

Answer 1

Firstly, your string isn't closed above.首先，你的字符串没有在上面关闭。 I assume that it is in your actual code.我假设它在您的实际代码中。

Check that the image is on your classpath, in that location.检查图像是否在您的类路径上，在该位置。 I had a similar issue as I was forgetting to deploy my images to my compiled classes folder, ready for building into a JAR.我有一个类似的问题，因为我忘记将我的图像部署到我编译的类文件夹中，准备构建到 JAR 中。

You may have to add a forward slash at the front, to reference it from the root of your classpath.您可能需要在前面添加一个正斜杠，以便从类路径的根目录引用它。 Otherwise, it may be trying to locate that relative path from the calling class.否则，它可能会尝试从调用类中定位该相对路径。 See here: How do I reference a resource in Java?请参阅此处：如何在 Java 中引用资源？

I tried the following test:我尝试了以下测试：

package test.game;

import javafx.application.Application;
import javafx.scene.Group;
import javafx.scene.Scene;
import javafx.scene.image.Image;
import javafx.scene.image.ImageView;
import javafx.stage.Stage;

public class MainApp extends Application {
    @Override
    public void start(Stage stage) {
        Image image = new Image(MainApp.class.getResourceAsStream("photos/faces/Sunset01.jpg"), 400, 200, true, true);
        ImageView imageView = new ImageView();
        imageView.setImage(image);

        Group group = new Group(imageView);
        Scene scene = new Scene(group, 800, 600);

        stage.setScene(scene);
        stage.setTitle("Main App");
        stage.show();
    }
}

I put my MainApp.java file in test/game and my Sunset01.jpg in test/game/photos/faces.我将 MainApp.java 文件放在 test/game 中，将 Sunset01.jpg 放在 test/game/photos/faces 中。 And it worked fine.它工作得很好。 So, it must be an issue with your image loading, being copied to your output directory, your runtime classpath or your photoList being initialized (eg List<Image> photoList = new ArrayList<>(); ).因此，这一定是您的图像加载、被复制到您的输出目录、您的运行时类路径或您的 photoList 被初始化的问题（例如List<Image> photoList = new ArrayList<>(); ）。

无法加载图像获取空指针异常

问题描述

1 个解决方案

解决方案1
0 2016-03-10 18:44:23

无法加载图像获取空指针异常

问题描述

1 个解决方案

解决方案1 0 2016-03-10 18:44:23

解决方案1
0 2016-03-10 18:44:23