Where do you get these numbers from? On my five year old MacBook Pro with default JVM options parsing a 20 MB file:
real 0m0.248s
user 0m0.325s
sys 0m0.043s
> 2. Memory usage of Java objects is quite heavy.
That's IBMs enterprise VM that uses three word headers. HotSpot is actually better. If you compare that with other "lightweight" programming languages it is really, really light.
A quarter of a second to start up the VM, run some code, and exit again is actually pretty steep compared to typical interpreted and compiled languages. Among other things, this means that you can't really call Java executables from a loop in a shell script.
For comparison purposes, both Ruby and Rust will show between "0.00 elapsed" and "0.02 elapsed" for a simple "Hello, world" program on my laptop.
To do a fair comparison, with your example, I just compiled and ran Hello World in Java on my machine and got this:
real 0.06 user 0.06 sys 0.01