Why am i getting a NullPointer?

i m trying to create a videoplayer that getting videos from a path in the sdcard.unfortunately i m getting a nullpointer!Could you please help me?? this is the code:

class VideoFilter implements FilenameFilter {
    public boolean accept(File dir, String name) {
        return (name.endsWith(".wmv"));
    }
}
public class video extends ListActivity {

    private static final String MEDIA_PATH = new String("/sdcard/videodata/");
    private List<String> songs = new ArrayList<String>();
    ArrayAdapter<String> videoList ;
    File home = new File(MEDIA_PATH);
private VideoView mVideoView;

    @Override
    public void onCreate(Bundle icicle) {


           try {
                super.onCreate(icicle);
                setContentView(R.layout.main3);
                updateVideoList();
            } catch (NullPointerException e) {
                Log.v(getString(R.string.app_name), e.getMessage());
            }


    }

    private void updateVideoList() {
        // TODO Auto-generated method stub 
        if (home.listFiles( new VideoFilter()).length > 0) {
            for (File file : home.listFiles( new VideoFilter())) {
                songs.add(file.getName());
            }
    videoList开发者_开发知识库 = new ArrayAdapter<String>(this,R.layout.video_item,songs);

            setListAdapter(videoList);
        }
    }

    @Override
    protected void onListItemClick(ListView l, View v, int position, long id) {



        mVideoView.setVideoPath(MEDIA_PATH + songs.get(position));
        mVideoView.setMediaController(new MediaController(this));
        mVideoView.requestFocus();
    }

}

@martin if i do it like that

@Override
    protected void onListItemClick(ListView l, View v, int position, long id) {

        setContentView(R.layout.main2);
        mVideoView = (VideoView) findViewById(R.id.VideoView);

        mVideoView.setVideoPath(MEDIA_PATH + songs.get(position));
        mVideoView.setMediaController(new MediaController(this));
        mVideoView.requestFocus();
    }

then i m getting 07-03 15:55:55.190: ERROR/AndroidRuntime(4090): java.lang.RuntimeException: Your content must have a ListView whose id attribute is 'android.R.id.list'

EDIT:

public class mainscreen extends Activity {

    Bundle extras = getIntent().getExtras();
    final int VIDEOS = extras.getInt("VIDEO");  
    private VideoView mVideoView;

   String k= new Integer(VIDEOS).toString();
    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState); 
        setContentView(R.layout.main2);

        mVideoView = (VideoView) findViewById(R.id.VideoView);
        mVideoView = (VideoView) findViewById(R.id.video);
        mVideoView.setVideoPath(k);
        mVideoView.setMediaController(new MediaController(this));
        mVideoView.requestFocus();

        }

thats the way i m passing the path string from the first activity t the second but its not working.............

You need to fetch your videoview first:

mVideoView = (VideoView) findViewById(R.id.myvideoview);

Edit

Your content must have a ListView whose id attribute is 'android.R.id.list'. It's as simple as that. In your main2.xml you need a ListView with the id 'list'.

Edit2

So you want to get rid of your ListView as you play the video. I'd recommend indeed starting a new Activity for this. ListActivity doesn't allow contents without a ListView.