vlcj無法在默認安裝文件夾中找到插件庫，NativeDiscovery有效

Question

我正在嘗試將vlcj與我的Java應用程序捆綁在一起，但是如果沒有本機發現，就無法加載vlcj。 我的Java和VLC安裝都是64位的，因此沒有問題。 使用本機發現時，我可以使視頻正常播放。 我嘗試了JNA 3.5.2，JNA 4.1.0，JNA 4.5.1，並且都產生了相同的結果

我可以得到的最簡單的示例：

public class Test {

private final JFrame frame;

private final EmbeddedMediaPlayerComponent mediaPlayerComponent;

public static void main(final String[] args) {

    NativeLibrary.addSearchPath(RuntimeUtil.getLibVlcLibraryName(), "C:\\Program Files\\VideoLAN\\VLC");
    System.setProperty("VLC_PLUGIN_PATH",  "C:\\Program Files\\VideoLAN\\VLC\\plugins");
    System.out.println(LibVlc.INSTANCE.libvlc_get_version());

    SwingUtilities.invokeLater(new Runnable() {
        @Override
        public void run() {
            new Test(args);
        }
    });
   }

public Test(String[] args) {
    frame = new JFrame("My First Media Player");
    frame.setBounds(100, 100, 600, 400);
    frame.setDefaultCloseOperation(JFrame.DO_NOTHING_ON_CLOSE);
    frame.addWindowListener(new WindowAdapter() {
        @Override
        public void windowClosing(WindowEvent e) {
            mediaPlayerComponent.release();
            System.exit(0);
        }
    });
    mediaPlayerComponent = new EmbeddedMediaPlayerComponent();
}
   }

堆棧跟蹤：

[main] INFO uk.co.caprica.vlcj.Info - vlcj: 3.10.1
[main] INFO uk.co.caprica.vlcj.Info - java: 10.0.1 Oracle Corporation
[main] INFO uk.co.caprica.vlcj.Info - java home: C:\Program Files\Java\jdk-10.0.1
[main] INFO uk.co.caprica.vlcj.Info - os: Windows 10 10.0 amd64
3.0.3 Vetinari
[AWT-EventQueue-0] INFO uk.co.caprica.vlcj.binding.LibVlcFactory - vlc:      3.0.3 Vetinari, changeset 3.0.3-1-0-gc2bb759264
[AWT-EventQueue-0] INFO uk.co.caprica.vlcj.binding.LibVlcFactory - libvlc: C:\Program Files\VideoLAN\VLC\libvlc.dll
[AWT-EventQueue-0] ERROR uk.co.caprica.vlcj.player.MediaPlayerFactory - Failed to initialise libvlc
Exception in thread "AWT-EventQueue-0" java.lang.RuntimeException: Failed to initialise libvlc.

This is most often caused either by an invalid vlc option being passed when creating a MediaPlayerFactory or by libvlc being unable to locate the required plugins.

If libvlc is unable to locate the required plugins the instructions below may help:

In the text below <libvlc-path> represents the name of the directory containing "libvlc.dll" and "libvlccore.dll" and <plugins-path> represents the name of the directory containing the vlc plugins...

For libvlc to function correctly the vlc plugins must be available, there are a number of different ways to achieve this:
 1. Make sure the plugins are installed in the "<libvlc-path>/plugins" directory, this should be the case with a normal vlc installation.
 2. Set the VLC_PLUGIN_PATH operating system environment variable to point to "<plugins-path>".

More information may be available in the log.


at uk.co.caprica.vlcj.player.MediaPlayerFactory.<init>(MediaPlayerFactory.java:300)
at uk.co.caprica.vlcj.player.MediaPlayerFactory.<init>(MediaPlayerFactory.java:259)
at uk.co.caprica.vlcj.component.EmbeddedMediaPlayerComponent.onGetMediaPlayerFactory(EmbeddedMediaPlayerComponent.java:349)
at uk.co.caprica.vlcj.component.EmbeddedMediaPlayerComponent.<init>(EmbeddedMediaPlayerComponent.java:217)
at vlctest.Test.<init>(Test.java:46)
at vlctest.Test$1.run(Test.java:30)
at java.desktop/java.awt.event.InvocationEvent.dispatch(InvocationEvent.java:313)
at java.desktop/java.awt.EventQueue.dispatchEventImpl(EventQueue.java:770)
at java.desktop/java.awt.EventQueue.access$600(EventQueue.java:97)
at java.desktop/java.awt.EventQueue$4.run(EventQueue.java:721)
at java.desktop/java.awt.EventQueue$4.run(EventQueue.java:715)
at java.base/java.security.AccessController.doPrivileged(Native Method)
at java.base/java.security.ProtectionDomain$JavaSecurityAccessImpl.doIntersectionPrivilege(ProtectionDomain.java:87)
at java.desktop/java.awt.EventQueue.dispatchEvent(EventQueue.java:740)
at java.desktop/java.awt.EventDispatchThread.pumpOneEventForFilters(EventDispatchThread.java:203)
at java.desktop/java.awt.EventDispatchThread.pumpEventsForFilter(EventDispatchThread.java:124)
at java.desktop/java.awt.EventDispatchThread.pumpEventsForHierarchy(EventDispatchThread.java:113)
at java.desktop/java.awt.EventDispatchThread.pumpEvents(EventDispatchThread.java:109)
at java.desktop/java.awt.EventDispatchThread.pumpEvents(EventDispatchThread.java:101)
at java.desktop/java.awt.EventDispatchThread.run(EventDispatchThread.java:90)

知道可能是什么原因嗎？

Answer 1

因此，感謝cubrr，我得以解決此問題。 只需創建一個設置環境變量的批處理文件，然后運行jar即可使其工作。

set VLC_PLUGIN_PATH=C:\Program Files\VideoLAN\VLC\plugins
start cmd.exe /c start "" javaw -jar test.jar

請注意，使用javaw運行jar會使控制台窗口關閉，因此使用Java會使控制台窗口不停留在應用程序窗口下方。

同樣也要留在這里：ClassLoader可用於加載libvlc.dll和libvlccore.dll

File jarDir = new File(ClassLoader.getSystemClassLoader().getResource(".").getPath());
NativeLibrary.addSearchPath(RuntimeUtil.getLibVlcLibraryName(), jarDir.getAbsolutePath());`

如果您的jar文件和dll位於同一目錄中，則此方法有效。