解决了的。这就成功了。

String mrl = new File(vids).getAbsolutePath();

我真傻下面是最后一段代码，我将视频路径保存在mysql数据库中：

public static void video() throws InterruptedException{
    MediaPlayerFactory mediaPlayerFactory = new MediaPlayerFactory();
    Canvas canvas = new Canvas();
    canvas.setBackground(Color.black);
    CanvasVideoSurface videoSurface = mediaPlayerFactory.newVideoSurface(canvas);
    EmbeddedMediaPlayer mediaPlayer = mediaPlayerFactory.newEmbeddedMediaPlayer();
    mediaPlayer.setVideoSurface(videoSurface);
    MediaListPlayer mediaListPlayer = mediaPlayerFactory.newMediaListPlayer();
    mediaListPlayer.addMediaListPlayerEventListener(new MediaListPlayerEventAdapter() {
        @Override
        public void nextItem(MediaListPlayer mediaListPlayer, libvlc_media_t item, String itemMrl) {
            System.out.println("nextItem()");
        }
    });
    mediaListPlayer.setMediaPlayer(mediaPlayer); // <--- Important, associate the media player with the media list player
    vid.add(canvas);
    MediaList mediaList = mediaPlayerFactory.newMediaList();
    String[] options = {};
    LinkedList<String> video = new LinkedList<>(); 
    try{
        Class.forName("com.mysql.jdbc.Driver");
        String url = "jdbc:mysql://localhost/mediaplaylist";
        Connection conn = DriverManager.getConnection(url,"root","");
        Statement stmt = conn.createStatement();
        String sqlSelect= "select * from media";
            ResultSet rs = stmt.executeQuery(sqlSelect);
        while(rs.next()){
            String vids= rs.getString("videos");

        String mrl = new File(vids).getAbsolutePath();
            System.out.println(mrl);

          mediaList.addMedia(mrl); 
          System.out.println(mediaList.items());
          mediaList.mediaListInstance();
          mediaListPlayer.setMediaList(mediaList);
          mediaListPlayer.setMode(MediaListPlayerMode.LOOP);
          mediaListPlayer.play();
        } 

    }catch (Exception ex) {

    Logger.getLogger(home.class.getName()).log(Level.SEVERE, null, ex);
    }
    }