Spring boot 404 white label error when executing as Java application

Question

I have a basic Spring Boot application created from Start.spring.io

Have the following package structure:

And the controller code is following:

@RestController
@RequestMapping("/api")
public class Controller {

    @GetMapping("/hello")
    public String test() {
        return "hello";
    }
}

When I execute this on an existing Tomcat server on my PC It is running succesfully. But when I execute this as a Java Application from eclipse I get a 404 white label error