Thread: Method access problem

I'm trying to get access to a method that is outside of three classes that extend each other. Basically the three classes below are linked together by the extends.

class CheckedTime extends class PreciseTime extends class Time.

I have a third class LocalCall that extends an abstract class PhoneCall

I have two objects of CheckedTime(int, int, int) that make up my LocalCall(CheckedTime, CheckedTime) constructor. I have a method that needs to access a method in PreciseTime, but am receiving a NullPointerException since I can't determine how to call the particular method. Here's the line in my LocalCall class causing the exception.

callLength = endTime.toSeconds() - startTime.toSeconds();

How can I write this line to access my PreciseTime method from LocalCall? I've been stumped on this for 3 days.

That is nowhere near enough information. For starters, post your full stack trace for the NullPointerException. Anybody wanting to help you on this would want to be sure exactly where the NPE was thrown.

Enter file name to read: testdata.txt
Calltype: L
StartTime: 07:30:00
EndTime: 07:30:00
Made it into the "L" else-loop, creating CheckedTime object
CheckedTime objects created
Created new LocalCall object:
Added LOCAL call to ArrayList
Exception in thread "main" java.lang.NullPointerException
at LocalCall.computeCost(LocalCall.java:43)
at MonthlyPhoneBill.main(MonthlyPhoneBill.java:142