The jvm is a pretty insane beast. It will do usage based recompilation, escape analysis for memory, so non heap allocation is super fast, has great memory safety...
But a lot of people use it with spring/spring boot, a technology designed to work around the complexities of a particular type of middleware software in the late 90s and early 2000s. It's cargo cult programming of the highest order.
In the OP, the author is comparing apples with oranges, with a bit of misunderstanding that java/jvm means spring boot, and while that is true for a lot of people and certainly a lot of stuff on the internet implies that 'this is the way', it's not required.
Startup times of ~100ms are absolutely standard for a big program, similarly unit tests taking 1ms.
I prefer to write kotlin rather than java, as it's a nicer language ,IMHO, but still those bytecodes run on Jvm and same stuff applies.
Edit: im not advocating writing 'ls' in java, and I would also agree that java uses more memory for small programs, so its not a systems programming language probably.
Just use new() it's pretty fast.
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