I\'m currently working on a REST API with Spring Boot.
I\'m new to Maven and have just started coding with IDEA (don\'t know well this IDE yet), and I have a problem
You need to tell SpringBoot where to look for your controllers. Per default that only happens in sub-packages of your @SpringBootApplication class (which will probably not include your sub module).
In order to change that you can use @ComponentScan("path.to.package") to change the default package.
Additionally, you can use @EntityScan to do the same for @Entity classes that might be in your sub-module.