Make a assign module.
Add a two new module inside the assign module, cal-api, cal-impl.
Make Calculator class inside cal-api which will have all the +, -, *, / method for integer value.
Create the Application class(It is a java main class) inside the cal-impl module inside src/main/java director.
Call the calculator method inside main class.
Add the CheckStyle plugin in the main pom.
Add the Spot bug plugin sin the main pom.
Add executable plugin in the main pom.
It should be a multi-module project.
Then you can execute the jar that is present in module which has main class.