java - Instantiating a web view media player within a JavaFX application -

i writing piece of educational software, , want user able select video watch list lies within javafx gui.

i have created mediaplayer class contains main method runs code , displays video correctly, next task instantiate mediaplayer class, , pass url of video watched parameter.

i have attempted code mediaplayertest, whereby instantiate mediaplayer, pass url parameter, , call start() method, getting following errors when running tester class:

exception in thread "main" java.lang.exceptionininitializererror     @ javafx.scene.web.webview.<init>(webview.java:271)     @ media.mediaplayer.start(mediaplayer.java:34)     @ media.mediaplayertest.main(mediaplayertest.java:23) caused by: java.lang.runtimeexception: internal graphics not initialized yet     @ com.sun.glass.ui.screen.getscreens(screen.java:70)     @ com.sun.javafx.webkit.prism.prismgraphicsmanager.<init>(prismgraphicsmanager.java:43)     @ javafx.scene.web.webengine.<clinit>(webengine.java:290)     ... 3 more 

any solving issue appreciated, can find tester class , mediaplayer class code below:

mediaplayer

import javafx.application.application; import javafx.scene.scene; import javafx.scene.web.webview; import javafx.stage.stage;  public class mediaplayer extends application {         public static void main(string[] args) { launch(args); }     // url of video played   string url = "https://www.youtube.com/embed/cysfqy_lgr4";    public mediaplayer(string url) {        this.url = url;    }    @override public void start(stage stage) throws exception {     webview webview = new webview();     webview.getengine().load(url);     webview.setprefsize(640, 390);      stage.setscene(new scene(webview));     stage.show();   }     } 

mediaplayertest

package media;  import java.util.logging.level; import java.util.logging.logger;   /**  *  * @author joe  */ public class mediaplayertest {      public static void main (string[] args) {          try {             mediaplayer mp = new mediaplayer("https://www.youtube.com/embed/cysfqy_lgr4");             mp.start(null);         } catch (exception ex) {             logger.getlogger(mediaplayertest.class.getname()).log(level.severe, null, ex);         }     }  } 

you should not invoke start() yourself: invoked part of complex process when call launch().

so can do:

import javafx.application.application; import javafx.scene.scene; import javafx.scene.web.webview; import javafx.stage.stage;  import java.util.list ;  public class mediaplayer extends application {         public static void main(string[] args) { launch(args); }     // url of video played   private string url = "https://www.youtube.com/embed/cysfqy_lgr4";     @override public void start(stage stage) throws exception {      list<string> params = getparameters.getraw();     if (params.size() > 0) {         url = params.get(0);     }      webview webview = new webview();     webview.getengine().load(url);     webview.setprefsize(640, 390);      stage.setscene(new scene(webview));     stage.show();   }     } 

and (if want, typically not approach):

import java.util.logging.level; import java.util.logging.logger;   /**  *  * @author joe  */ public class mediaplayertest {      public static void main (string[] args) {          try {             application.launch(mediaplayer.class, "https://www.youtube.com/embed/cysfqy_lgr4");         } catch (exception ex) {             logger.getlogger(mediaplayertest.class.getname()).log(level.severe, null, ex);         }     }  } 

obviously here mediaplayertest class redundant anyway: can run mediaplayer class directly.

the bottom line application subclasses represent entry point of application, , such not designed reusable. if want reuse mediaplayer class elsewhere, refactor it's not application subclass. see java: how start standalone application current 1 when both in same package?