https://github.com/boot-clj/boot/blob/master/boot/base/src/m... looks like the gnu standard for C (https://www.gnu.org/prep/standards/standards.html#Formatting), applied to Java.
I think that was done to make grepping for function definitions easier (when searching for the definition of foo, grep for “^foo\b”. That makes implementing “go to function definition” possible without having to parse code)