Multiple @SpringBootApplication Annotation in a Project

I recently faced the same scenario here and I solved with a simple solution.

My projected uses Maven and is configured with sub-modules like this:

my-parent
  |__ my-main (depends on my-other module)
  |__ my-other

Each module has its own main App class annotated with @SpringBootApplication. The problem is that both classes reside in the same package even though they are in different modules.

Once I start MyMainApp it also starts MyOtherApp. To avoid this I just had to do the following.

In the my-main module I have:

@SpringBootApplication
public class MyMainApp ... { ... }

and in the my-other module I have:

@SpringBootApplication
@ConditionalOnProperty(name = "my.other.active", havingValue = "true", matchIfMissing = false)
public class MyOtherApp ... { ... }

with application.properties with:

my.other.active=true

It works as expected.

The @SpringBootApplication annotation is a shortcut annotation for @Configuration, @EnableAutoConfiguration, and @ComponentScan.

http://docs.spring.io/spring-boot/docs/current/reference/html/using-boot-using-springbootapplication-annotation.html

The default behavior of @ComponentScan is to look for @Configuration and @Component classes within the same package and all sub-packages of the annotated class. Since all your classes are in the same package, when you start any one of them Spring will find the others and treat them like @Configuration classes, and register their beans, etc.

So yes, this is expected behavior given your project setup. Put each @SpringBootApplication class in a separate subpackage if you don't want this to happen for local testing. If this moves beyond a demo at some point you'll probably want to come up with a better setup (subprojects for each @SpringBootApplication perhaps).