There seems to be a bug in the XMPPConnection class in Smack 3.0.0 Beta.
When connecting and then immediately disconnecting without logging in a NullPointerException is thrown.
A quick look at the source shows that in line 636 of XMPPConnection a call is made to cleanup the roster. However, in this scenario the roster has not yet been initialized.
Should be easy enough to fix…
Kind regards,
Lars