You program did not start a valid pointer.
The pointer was empty.
A pointer was empty but it was never started.
the only "pointers" in java are the object reference pointers, which are object types. for example, you can declare a variable as a ArrayList but unless you set it to an instance of an ArrayList it is a null pointer, and any attempt to access the methods of the variable results in an NullPointerException.
of course since no actual code was provided it's impossible to determine the exact cause of the issue. the only helpful information here is that it occured in the main() routine.
