JavaFX / Netbeans程序未運行

Question

到目前為止，這是我在Netbeans程序中擁有的代碼。 應該打開一個帶有圖片的窗口，該圖片被稱為海浪。 但是由於某種原因它沒有運行。 你知道為什么嗎？

    package myseaapp;

import javafx.application.Application;
import javafx.scene.Scene;
import javafx.scene.image.Image;
import javafx.scene.image.ImageView;
import javafx.scene.layout.Pane;
import javafx.scene.shape.Rectangle;
import javafx.stage.Stage;
import javafx.stage.StageStyle;

public class MySeaApp extends Application {

    private ImageView seawave;
    private Rectangle seawaveClip;

    @Override
    public void start(Stage primaryStage) {
       primaryStage.initStyle(StageStyle.TRANSPARENT);

       seawave = new ImageView(new Image(MySeaApp.class.getResourceAsStream("images/seawave")));
       seawaveClip = new Rectangle(300, 220);
       seawaveClip.setArcHeight(20);
       seawaveClip.setArcWidth(20);

       seawave.setClip(seawaveClip);
       Pane root = new Pane();
       root.getChildren().add(seawave);

       Scene myScene = new Scene(root, 300, 250);
       myScene.setFill(null);
       primaryStage.setScene(myScene);
       primaryStage.show();
    }

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

}

這就是我得到的...

Executing /Users/SethRataiczak/NetBeansProjects/MySeaApp/dist/run1104410607/MySeaApp.jar using platform /Library/Java/JavaVirtualMachines/jdk1.8.0_60.jdk/Contents/Home/jre/bin/java
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$156(LauncherImpl.java:182)
    at java.lang.Thread.run(Thread.java:745)
Caused by: java.lang.NullPointerException: Input stream must not be null
    at javafx.scene.image.Image.validateInputStream(Image.java:1110)
    at javafx.scene.image.Image.<init>(Image.java:694)
    at myseaapp.MySeaApp.start(MySeaApp.java:30)
    at com.sun.javafx.application.LauncherImpl.lambda$launchApplication1$163(LauncherImpl.java:863)
    at com.sun.javafx.application.PlatformImpl.lambda$runAndWait$176(PlatformImpl.java:326)
    at com.sun.javafx.application.PlatformImpl.lambda$null$174(PlatformImpl.java:295)
    at java.security.AccessController.doPrivileged(Native Method)
    at com.sun.javafx.application.PlatformImpl.lambda$runLater$175(PlatformImpl.java:294)
    at com.sun.glass.ui.InvokeLaterDispatcher$Future.run(InvokeLaterDispatcher.java:95)
Exception running application myseaapp.MySeaApp
Java Result: 1
Deleting directory /Users/SethRataiczak/NetBeansProjects/MySeaApp/dist/run1104410607
jfxsa-run:
BUILD SUCCESSFUL (total time: 1 second)

Answer 1

首先，使用try and catch塊進行此類錯誤處理

try {
 // code 
}catch {
 // error handling code
}

其次，您沒有使用圖像類型例如.png，.jpg等

seawave = new ImageView(new Image(MySeaApp.class.getResourceAsStream("images/seawave")));

使用正確的圖像類型更改此代碼行

像這樣：

seawave = new ImageView(new Image(MySeaApp.class.getResourceAsStream("images/seawave.jpg")));