JavaDocUtil.invokeMaven throws IllegalArgumentException for null arguments

[elharo]

Affected version

HEAD

Bug description

These should be NullPointerExceptions, per Effective Java

[olamy]

I personally find IllegalArgumentException more human-readable or self explanatory as it explains by itself the nature of the problem. `
Effective Java is just a book with the opinion from someone. We can have different POVs and make errors more friendly.

[elharo]

I don't know why. IllegalArgumentException doesn't do anything NullPointerException doesn't. It just depends on whatever message the constrcuting code supplies. Starting in JDK 15 NullPointerException gets noticeably better than IllegalArgumentException