There are plenty of examples of basic Dockerfile based builds out there, but a production application requires a bunch of different things, such as reproducibility, hardening, health checks, static analysis - and ideally still be quick to build.
Modern containerised 12 factor applications are expected to derive their configuration from environment variables. While Spring Boot does import its common properties from environment variables, sometimes you need to interpolate several variables together, e.g. to form a URL.
Spring MVC abstracts the Java servlet container implementation away from you almost completely, this allows you to migrate from Tomcat quite easily.