title: Getting an exception when running some code
body: <p>I'm trying to run some code that imports <code>test.x3dv</code> in Java. The Java code that I have is: </p>
  
  <pre><code>package xj3dtest;
  
  import java.awt.BorderLayout;
  import java.awt.Component;
  import java.awt.Container;
  import javax.swing.JFrame;
  import org.web3d.x3d.sai.Browser;
  import org.web3d.x3d.sai.BrowserFactory;
  import org.web3d.x3d.sai.X3DComponent;
  import org.web3d.x3d.sai.X3DScene;
  
  public class Xj3DTest extends JFrame {
  
      public Xj3DTest(String title) {
  
          super(title);
  
          setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
  
          X3DComponent x3dComponent = BrowserFactory.createX3DComponent(null);
  
          Browser browser = x3dComponent.getBrowser();
  
          Component browserComponent = (Component)  x3dComponent.getImplementation();
  
          Container cp = getContentPane();
          cp.setLayout(new BorderLayout());
          cp.add(browserComponent, BorderLayout.CENTER);
  
          X3DScene scene = browser.createX3DFromURL(new String[]   {"test.x3dv"});
  
          browser.replaceWorld(scene);
      }
  
      public static void main(String[] args) {
          Xj3DTest frame = new Xj3DTest("Xj3D test");
          frame.setSize(640, 480);
          frame.setLocationRelativeTo(null);
          frame.setVisible(true);
      }
  }
  </code></pre>
  
  <p>And the code for the test.x3dv file is:</p>
  
  <pre><code>#X3D V3.0 utf8
  
  PROFILE Interactive
  
  DEF TS TimeSensor {
    cycleInterval 3
    loop TRUE
  }
  
  DEF TG Transform {
    rotation 0 1 0 0
    children Shape {
      geometry Box {}
      appearance Appearance {
        material DEF MAT Material {
          diffuseColor 1 0 0
        }
      }
    }
  }
  
  DEF OI OrientationInterpolator {
    key [ 0 0.5 1 ]
    keyValue [
       0 1 0 0
       0 1 0 3.14
       0 1 0 6.28
    ]
  }
  
  ROUTE TS.fraction_changed TO OI.set_fraction 
  ROUTE OI.value_changed TO TG.rotation
  </code></pre>
  
  <p>When I run the code, I get the following: </p>
  
  <pre><code>Exception in thread "main" java.lang.NullPointerException
  Unable to find X3D browser factory implementation
  
  at    org.web3d.x3d.sai.BrowserFactory.createX3DComponent(BrowserFactory.java:252)
  at xj3dtest.Xj3DTest.&lt;init&gt;(Xj3DTest.java:20)
  at xj3dtest.Xj3DTest.main(Xj3DTest.java:36)
  </code></pre>
  
  <p>I believe it's to do with the <code>Component browserComponent = (Component)  x3dComponent.getImplementation();</code> line and trying to call a method on a null object and I don't know how to fix it. If anyone can help, it would be greatly appreciated.  </p>
  
  <p><strong>EDIT</strong> 
  I was wondering how I'd go about trying to fix that one line so it works. That other question is useful but I'm struggling to see how I can use it for this line.</p>