You have to provide a direct link to your video.
Try to change this line:
Uri uri = Uri.parse("http://www.learnixmba.com/doajax.php?profile=2809");
To this:
Uri uri = Uri.parse("http://pdl.vimeocdn.com/01593/020/145269025.mp4?token2=1388403392_f17d62baae773f48f5b1565a69857345&aksessionid=1ba8f3ac4cafca62");
EDIT: DISPLAY YOUTUBE VIDEOS
String videoId = "0HDsz3C9IHg"; // id of the youtube video you want to display
Intent intent = new Intent(Intent.ACTION_VIEW, Uri.parse("vnd.youtube:"+videoId));
intent.putExtra("VIDEO_ID", videoId);
startActivity(intent);
OR DIRECT LINK TO VIDEO, PLAYING IN THE YOUTUBE PLAYER:
Intent videoClient = new Intent(Intent.ACTION_VIEW);
videoClient.setData("VALID YOUTUBE LINK WITH HTTP");
videoClient.setClassName("com.google.android.youtube","com.google.android.youtube.WatchActivity");
startActivity(videoClient);