Java does not support Operator Overloading.
The only option you have is define methods like
add(), subtract(), multiply(), etc, and write the logic there,
and invoke them for particular operation.
You can have a look at BigInteger class to get an idea of how you can
define methods to support various operations. And if interested,
you can even go through the source code, that you can find in the src folder
of your jdk home directory.