NULL Pointer Exception when integrating g+ Signin

Question

This is my code

public class gsign extends Activity implements ConnectionCallbacks,OnConnectionFailedListener {
private static final int RC_SIGN_IN = 0;
private          


        

Answer 1

The stack trace tells it all...

You don't call mGoogleApiClient.connect() until onStart(). Meanwhile back in onCreate(), which is called before onStart(), you call the signInWithGplus(); method.

!mGoogleApiClient.isConnecting() in that method is true leading to resolveSignInError() being called.

You have not yet assigned a value to mConnectionResult so calling mConnectionResult.hasResolution() in resolveSignInError() will throw a NullPointerException.