[jdom-interest] malformed URL exception exception in saxbuilder.build due to unreachable URL

[Michael Kay]

> Having read some things recently in Effective Java, and also more 
> carefully implementing core API's like the Collections API, I am now 
> more inclined to do an explicit null check, and throw 
> NullPointerException.
I started putting @Nullable and @NotNull assertions into my code, and 
this got very confusing. I don't know about other tools, but IntelliJ 
gives you warnings if you say @NotNull and then have an "if null" test, 
while if you say @Nullable then the wrong information is conveyed to the 
user of the API.

Michael Kay
Saxonica