Authenticating Vaadin-based applications: null pointer assignment

dear all,

I am having a problem running the wiki example.

The Statement “SMSApp.getInstance ()” always returns a null pointer and in the consequence the authenticate method cannot be executed.

I am running the example code with Tomcat v6.0 Server at localhost [Apache Tomcat]
/usr/lib/jvm/java-6-sun-1.6.0.22
and vaadin: 6.4.7

Any help is much appreciated.
Ray

I cannot directly see anything wrong in the example, but what you described would mean that the currentApplication instance is not set. This happens, for example, if you haven’t registered your application as a transaction listener and thus transactionStart is never called.

If you don’t want to implement authentication yourself, you could always use, for example, the
AppFoundation add-on
and its
authentication module
.