using this code:
http://stackoverflow.com/questions/10913682/how-to-capture-and-save-an-image-using-custom-camera-in-android

Getting error in line number: 28, which is :     mCamera.setPreviewDisplay(surfaceHolder); [CameraPreview.java]

Logcat says:

05-30 10:18:17.496: E/AndroidRuntime(807): FATAL EXCEPTION: main
05-30 10:18:17.496: E/AndroidRuntime(807): java.lang.NullPointerException
05-30 10:18:17.496: E/AndroidRuntime(807): 	at com.example.demo.CameraPreview.surfaceCreated(CameraPreview.java:28)
05-30 10:18:17.496: E/AndroidRuntime(807): 	at android.view.SurfaceView.updateWindow(SurfaceView.java:569)
05-30 10:18:17.496: E/AndroidRuntime(807): 	at android.view.SurfaceView.access$000(SurfaceView.java:86)
05-30 10:18:17.496: E/AndroidRuntime(807): 	at android.view.SurfaceView$3.onPreDraw(SurfaceView.java:174)
05-30 10:18:17.496: E/AndroidRuntime(807): 	at android.view.ViewTreeObserver.dispatchOnPreDraw(ViewTreeObserver.java:680)
05-30 10:18:17.496: E/AndroidRuntime(807): 	at android.view.ViewRootImpl.performTraversals(ViewRootImpl.java:1842)
05-30 10:18:17.496: E/AndroidRuntime(807): 	at android.view.ViewRootImpl.doTraversal(ViewRootImpl.java:989)
05-30 10:18:17.496: E/AndroidRuntime(807): 	at android.view.ViewRootImpl$TraversalRunnable.run(ViewRootImpl.java:4351)
05-30 10:18:17.496: E/AndroidRuntime(807): 	at android.view.Choreographer$CallbackRecord.run(Choreographer.java:749)
05-30 10:18:17.496: E/AndroidRuntime(807): 	at android.view.Choreographer.doCallbacks(Choreographer.java:562)
05-30 10:18:17.496: E/AndroidRuntime(807): 	at android.view.Choreographer.doFrame(Choreographer.java:532)
05-30 10:18:17.496: E/AndroidRuntime(807): 	at android.view.Choreographer$FrameDisplayEventReceiver.run(Choreographer.java:735)
05-30 10:18:17.496: E/AndroidRuntime(807): 	at android.os.Handler.handleCallback(Handler.java:725)
05-30 10:18:17.496: E/AndroidRuntime(807): 	at android.os.Handler.dispatchMessage(Handler.java:92)
05-30 10:18:17.496: E/AndroidRuntime(807): 	at android.os.Looper.loop(Looper.java:137)
05-30 10:18:17.496: E/AndroidRuntime(807): 	at android.app.ActivityThread.main(ActivityThread.java:5041)
05-30 10:18:17.496: E/AndroidRuntime(807): 	at java.lang.reflect.Method.invokeNative(Native Method)
05-30 10:18:17.496: E/AndroidRuntime(807): 	at java.lang.reflect.Method.invoke(Method.java:511)
05-30 10:18:17.496: E/AndroidRuntime(807): 	at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:793)
05-30 10:18:17.496: E/AndroidRuntime(807): 	at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:560)
05-30 10:18:17.496: E/AndroidRuntime(807): 	at dalvik.system.NativeStart.main(Native Method)