NPEs happening a lot happen in all applications. It isn't Spring specific. NPEs is my bane in
Java development. I get it a lot, and that was even before I ever used Spring.
But I will say that you just can't get around a NPE happening if an object is set to null and you try to call a method etc.
Practices are
1) check for null before calling the object
2) never leave an object at null
3) Make sure it is set.
4) You can do exception handling with AOP, but that won't stop NPEs or other exceptions, just a nice centralized location for Exception Handling.
Mark