JavaFx添加图像

Question

无论我做什么来改变它，我都会不断得到这个错误。我对JavaFX非常陌生，我想尝试一个小程序。我只是想让一张照片出现在现场，但我甚至不能让图像加载到我的程序中。我将图像放在主包（seaapp）旁边的包（seaapp.images）中

package seaapp;

import javafx.application.Application;
import javafx.event.ActionEvent;
import javafx.event.EventHandler;
import javafx.scene.Scene;
import javafx.scene.control.Button;
import javafx.scene.image.Image;
import javafx.scene.image.ImageView;
import javafx.scene.layout.Pane;
import javafx.scene.layout.StackPane;
import javafx.stage.Stage;

public class SeaApp extends Application {

@Override
public void start(Stage primaryStage) {
    ImageView image = new ImageView(new Image(SeaApp.class.getResourceAsStream("images/space.png")));
    Pane root = new Pane();
    root.getChildren().add(image);
    Scene scene = new Scene(root, 300, 250);

    primaryStage.setTitle("Hello World!");
    primaryStage.setScene(scene);
    primaryStage.show();
}

public static void main(String[] args) {
    launch(args);
}

}

这给了我一个错误：

Exception in Application start method
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:497)
at com.sun.javafx.application.LauncherImpl.launchApplicationWithArgs(LauncherImpl.java:389)
at com.sun.javafx.application.LauncherImpl.launchApplication(LauncherImpl.java:328)
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.launcher.LauncherHelper$FXHelper.main(LauncherHelper.java:767)
Caused by: java.lang.RuntimeException: Exception in Application start method
at com.sun.javafx.application.LauncherImpl.launchApplication1(LauncherImpl.java:917)
at com.sun.javafx.application.LauncherImpl.lambda$launchApplication$152(LauncherImpl.java:182)
at com.sun.javafx.application.LauncherImpl$$Lambda$50/355629945.run(Unknown Source)
at java.lang.Thread.run(Thread.java:745)
Caused by: java.lang.NullPointerException: Input stream must not be null
at javafx.scene.image.Image.validateInputStream(Image.java:1109)
at javafx.scene.image.Image.<init>(Image.java:694)
at seaapp.SeaApp.start(SeaApp.java:27)
at com.sun.javafx.application.LauncherImpl.lambda$launchApplication1$159(LauncherImpl.java:863)
at com.sun.javafx.application.LauncherImpl$$Lambda$53/1175241703.run(Unknown Source)
at com.sun.javafx.application.PlatformImpl.lambda$runAndWait$172(PlatformImpl.java:326)
at com.sun.javafx.application.PlatformImpl$$Lambda$46/1685538367.run(Unknown Source)
at com.sun.javafx.application.PlatformImpl.lambda$null$170(PlatformImpl.java:295)
at com.sun.javafx.application.PlatformImpl$$Lambda$48/435396101.run(Unknown Source)
at java.security.AccessController.doPrivileged(Native Method)
at com.sun.javafx.application.PlatformImpl.lambda$runLater$171(PlatformImpl.java:294)
at com.sun.javafx.application.PlatformImpl$$Lambda$47/485815673.run(Unknown Source)
at com.sun.glass.ui.InvokeLaterDispatcher$Future.run(InvokeLaterDispatcher.java:95)
at com.sun.glass.ui.win.WinApplication._runLoop(Native Method)
at com.sun.glass.ui.win.WinApplication.lambda$null$145(WinApplication.java:101)
at com.sun.glass.ui.win.WinApplication$$Lambda$36/1673605040.run(Unknown Source)
... 1 more
Exception running application seaapp.SeaApp
Java Result: 1

当我添加一个图片的URL作为新图片时，这很好，但是当我有一个下载的图片时，它会给我这个错误。我的netbeans也完全更新了。我已经把我如何设置文件的截图链接。我错过什么了吗？

项目设置：

https://drive.google.com/file/d/0B_KZLduvxt26dE5XS1p5blE5VFE/view?usp=sharing

文件设置：

https://drive.google.com/file/d/0B_KZLduvxt26Nm1sZWROSlRMeUE/view?usp=sharing

链接到整个项目：

https://drive.google.com/file/d/0B_KZLduvxt26dXVFYlFhREFGZW8/view?usp=sharing

Answer 1

更改以下行：

ImageView图像=new ImageView（new Image（SeaApp.class.getResourceAsStream（"图像/space.png"）））

到

ImageView图像=new ImageView（new Image（SeaApp.class.getResourceAsStream（文件：./"图像/space.png））

参考：https://stackoverflow.com/a/23878479/6336264

Answer 2

这样做：

Image image = new Image( getClass().getResource( "images/space.png").toExternalForm());
ImageView image = new ImageView( image);

如果这不起作用，找出要查找的路径：

System.out.println( "Path: " + getClass().getResource("/").toExternalForm());
System.out.println( "Path: " + getClass().getResource("images").toExternalForm());
...

并检查图像是否存在。

Answer 3

在images/space.png之前添加一个正斜杠/，代码将正常工作（即，如果路径正确）。

ImageView image = new ImageView(new Image(SeaApp.class.getResourceAsStream("/images/space.png")));

编辑：

它应该很好用。