[1.12.2] NullPointerException caused when accessing ArrayList in a packet

[Tut]

I'm having some trouble with the fromBytes method when I'm implementing my own packet.

 

The packet is supposed to combine two chest's inventories into one. 

 

Here's the code.

 

Specifically, my issue regards line 43 of the tutmodMessage class. I'm getting a NullPointerException when accessing the newList List, and I'm not sure why. The toBytes method works completely fine, and the HuskItem class has nothing that would clear the newlist List before the fromByte method would access it.

 

Weird part is, that line of code worked before I implemented a large part of code in the handle() method. The previous working code can be seen here. (the array of chestPos and the for loop in fromBytes should be 3 in length. I was still figuring out how I was going to clear the chest contents.) 

 

Here's the crash log as well.

 

Am I just not understanding how the implementation of iMessage works? Or is something wrong in my constructor? Am I doing the whole reading and writing from the buffer wrong? Still trying to grasp how to use custom packets. Feel free to tell me other things I'm doing wrong. Thanks!

[Draco18s]

https://github.com/Excaliburns/ModPractice/blob/master/src/main/java/network/tutmodMessage.java#L43

 

When the packet is being reconstructed from the byte array...what is the value (and therefore its size) of itemsList?

I'll give you a hint, it's specified in the zero-argument constructor.

Edited November 8, 2017 by Draco18s

[Tut]

21 minutes ago, Draco18s said:

https://github.com/Excaliburns/ModPractice/blob/master/src/main/java/network/tutmodMessage.java#L43

 

When the packet is being reconstructed from the byte array...what is the value (and therefore its size) of itemsList?

I'll give you a hint, it's specified in the zero-argument constructor.

1

I just don't know why it's null. Is there something within Java that I just don't understand here?

 

Edit: I think I got it. Trying some stuff now.

Edited November 8, 2017 by Tut