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From Scott Arnold <sca7...@bjc.org>
Subject RE: Non-Null Object Is Null
Date Wed, 13 Jul 2016 15:34:41 GMT
Thought I would add a little more detail.  I'm using Groovy 2.3.7.  I thought this might be
somehow related to Groovy's NullObject, but you are supposed to be able to call getClass()
on NullObject based on info I have found online.  The very next line of my code is to just
call icf.getClass() and that is when the NullPointerException is thrown.

I'm going to go back and play around with the instantiation some more and see if that adds
any more clues.  I'm not sure what the repercussions are of using ICF icf (vs def icf) are.

-----Original Message-----
From: Scott Arnold [mailto:sca7740@bjc.org] 
Sent: Wednesday, July 13, 2016 10:01 AM
To: users@groovy.apache.org
Subject: Non-Null Object Is Null

I'm new to Groovy (lots of Java experience but almost no Groovy experience) and maybe there
is something very basic I am missing here, but I am running into the following issue in a
Grails app (but I think it's a not understanding Groovy issue).  I'm not sure I can break
it down any further than I already have, so I am kind of stumped about what I am doing wrong
here.

In case you know Grails and want some detail on where this code is happening, I'm working
on a pre-existing Grails app that calls a service from the BootStrap.groovy during application
startup.  The code I'm having a problem with is within the service class.

Here's the code snippet:

System.out.println("is icf null? " + (icf == null));
System.out.println("is icf not null? " + (icf != null));
System.out.println("what is icf? " + icf);

And here's the output:

is icf null? false
is icf not null? true
what is icf? Null

If I try to call a method on icf, I get a NullPointerException.  However, earlier in the code
icf is created (currently it is created Java-style rather than using def, as in ICF icf =
new ICF()) and the code tries to set several property values within icf (e.g. icf.code = suchandsuch)
and none of that throws any errors.

What might be happening here?

Thanks.

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