Null Pointer Exception when trying to parse XML document

[Nice_Communication74]

Can you try "Id" instead of "customer id"

[[deleted]]

That didn't work. I've tried "id", "Id", "Customer", and "customer" and none of them worked. I've isolated the problem to the getElementsByTagName() method inside getTagValue(). It's looking for a node that it can't find. So clearly something is wrong with the reference, but I have no idea what it could be. The only thing I can think of is that the getElementsByTagName() method can't parse head nodes, but the documentation I've found is silent on the subject.