JavaFX MediaPlayer 抛出 java.lang.reflect.InitationTargetException

Question

我一直在尝试使用 JavaFX MediaPlayer 类进行实验，并在不同的线程中发现了以下示例代码:

import java.net.URI;
import java.net.URISyntaxException;

import javafx.application.Application;
import javafx.scene.Group;
import javafx.scene.Scene;
import javafx.scene.media.Media;
import javafx.scene.media.MediaPlayer;
import javafx.scene.media.MediaView;
import javafx.stage.Stage;

public class test extends Application {

    @Override
    public void start(Stage primaryStage)
    {
        //Add a scene
        Group root = new Group();
        Scene scene = new Scene(root, 500, 200);
        URI file = null;
        try {
            file = new URI("/home/thomas/voodoo.mp3");
        } catch (URISyntaxException e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
            System.out.println("POOR URI SYNTAX");
        }
        Media pick = new Media(file.toString());
        MediaPlayer player = new MediaPlayer(pick);
        player.play();

        //Add a mediaView, to display the media. Its necessary !
        //This mediaView is added to a Pane
        MediaView mediaView = new MediaView(player);
        ((Group)scene.getRoot()).getChildren().add(mediaView);

        //show the stage
        primaryStage.setTitle("Media Player");
        primaryStage.setScene(scene);
        primaryStage.show();
    }
    public static void main(String[] args) {
         launch(args);
    }
}

我调整了文件路径以指向真实的音频文件(/home/thomas/voodoo.mp3)并尝试运行它，但控制台输出如下:

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:498)
    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:498)
    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$1(LauncherImpl.java:182)
    at java.lang.Thread.run(Thread.java:745)
Caused by: java.lang.IllegalArgumentException: uri.getScheme() == null! uri == '/home/thomas/voodoo.mp3'
    at com.sun.media.jfxmedia.locator.Locator.<init>(Locator.java:211)
    at javafx.scene.media.Media.<init>(Media.java:393)
    at test.start(test.java:28)
    at com.sun.javafx.application.LauncherImpl.lambda$launchApplication1$8(LauncherImpl.java:863)
    at com.sun.javafx.application.PlatformImpl.lambda$runAndWait$7(PlatformImpl.java:326)
    at com.sun.javafx.application.PlatformImpl.lambda$null$5(PlatformImpl.java:295)
    at java.security.AccessController.doPrivileged(Native Method)
    at com.sun.javafx.application.PlatformImpl.lambda$runLater$6(PlatformImpl.java:294)
    at com.sun.glass.ui.InvokeLaterDispatcher$Future.run(InvokeLaterDispatcher.java:95)
    at com.sun.glass.ui.gtk.GtkApplication._runLoop(Native Method)
    at com.sun.glass.ui.gtk.GtkApplication.lambda$null$5(GtkApplication.java:139)
    ... 1 more
Exception running application test

我的设置或代码有问题吗？

感谢您的帮助!

编辑:

按照纳什的建议更改为 Media pick = new Media(new File("/home/thomas/voodoo.mp3").toURI().toString());，但它仍然不起作用。不过，控制台输出现在有点不同。

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:498)
    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:498)
    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$1(LauncherImpl.java:182)
    at java.lang.Thread.run(Thread.java:745)
Caused by: MediaException: UNKNOWN : com.sun.media.jfxmedia.MediaException: Could not create player! : com.sun.media.jfxmedia.MediaException: Could not create player!
    at javafx.scene.media.MediaException.exceptionToMediaException(MediaException.java:146)
    at javafx.scene.media.MediaPlayer.init(MediaPlayer.java:511)
    at javafx.scene.media.MediaPlayer.<init>(MediaPlayer.java:414)
    at test.start(test.java:20)
    at com.sun.javafx.application.LauncherImpl.lambda$launchApplication1$8(LauncherImpl.java:863)
    at com.sun.javafx.application.PlatformImpl.lambda$runAndWait$7(PlatformImpl.java:326)
    at com.sun.javafx.application.PlatformImpl.lambda$null$5(PlatformImpl.java:295)
    at java.security.AccessController.doPrivileged(Native Method)
    at com.sun.javafx.application.PlatformImpl.lambda$runLater$6(PlatformImpl.java:294)
    at com.sun.glass.ui.InvokeLaterDispatcher$Future.run(InvokeLaterDispatcher.java:95)
    at com.sun.glass.ui.gtk.GtkApplication._runLoop(Native Method)
    at com.sun.glass.ui.gtk.GtkApplication.lambda$null$5(GtkApplication.java:139)
    ... 1 more
Caused by: com.sun.media.jfxmedia.MediaException: Could not create player!
    at com.sun.media.jfxmediaimpl.NativeMediaManager.getPlayer(NativeMediaManager.java:274)
    at com.sun.media.jfxmedia.MediaManager.getPlayer(MediaManager.java:118)
    at javafx.scene.media.MediaPlayer.init(MediaPlayer.java:467)
    ... 11 more
Exception running application test

Answer 1

问题是您的网址 /home/thomas/voodoo.mp3 无效，实际上该方案丢失，如错误消息中所述 (uri.getScheme() == null!uri == '/home/thomas/voodoo.mp3')，它应该以 file:// 开头，因为它是本地文件系统中的一个文件，因此它应该为file:///home/thomas/voodoo.mp3。

但是，由于像您当前所做的那样构建 URI 太容易出错，因为您必须确保它被正确的 URL 编码(例如，空格应替换为%20) 并且您需要提供有效的方案，您最好使用 Nash 建议的 new File(path).toURI().toString() .