import javafx.application.Application;
import javafx.scene.Scene;
import javafx.scene.web.WebView;
import javafx.stage.Stage;

public class FarsiWebTest extends Application {

    @Override
    public void start(final Stage primaryStage) throws Exception {
        String descriptionText = "این یک متن ساده به زبان فارسی است";
        WebView webView = new WebView();
        webView.getEngine().loadContent("<html><body><h1>Test</h1><br><h1>" + descriptionText + "</h1><br></body></html>", "text/html");
        Scene scene = new Scene(webView, 600, 300);
        primaryStage.setScene(scene);
        primaryStage.show();
        String userAgent = webView.getEngine().getUserAgent();
        primaryStage.setTitle("JavaFX " + System.getProperty("javafx.version") + ", WebKit: " + userAgent.substring(userAgent.indexOf("Safari") + 7)); //616.1, 617.1, 619.1 OK, 620.1 fails
    }
}
