org.springframework.beans.factory.UnsatisfiedDependencyException: Error creating bean with name ‘demoRestController’

Your DemoApplication class is in the com.ag.digital.demo.boot package and your LoginBean class is in the com.ag.digital.demo.bean package. By default components (classes annotated with @Component) are found if they are in the same package or a sub-package of your main application class DemoApplication. This means that LoginBean isn’t being found so dependency injection fails.

There are a couple of ways to solve your problem:

1. Move LoginBean into com.ag.digital.demo.boot or a sub-package.
2. Configure the packages that are scanned for components using the scanBasePackages attribute of @SpringBootApplication that should be on DemoApplication.

A few of other things that aren’t causing a problem, but are not quite right with the code you’ve posted:

• @Service is a specialisation of @Component so you don’t need both on LoginBean
• Similarly, @RestController is a specialisation of @Component so you don’t need both on DemoRestController
• DemoRestController is an unusual place for @EnableAutoConfiguration. That annotation is typically found on your main application class (DemoApplication) either directly or via @SpringBootApplication which is a combination of @ComponentScan, @Configuration, and @EnableAutoConfiguration.

In my case, this is erroring out during my unit test, apparently, not only do I have to add the new package on the Main class, but also on the Test configuration class where in the ComponentScan annotation specific to the test classes, I just added

com.bpg.csp.cbs.common.util

since this is the new package I added on my project. A snippet of my full test configuration code is below

@Profile("junit")
@Configuration
@ComponentScan(basePackages = {
        "com.bpg.services.booking.gds.adapter.impl.config",
        "com.bpg.csp.cbs.common.util"
})
public class TestConfiguration
{
}

To me it happened in DogController that autowired DogService that autowired DogRepository. Dog class used to have field name but I changed it to coolName, but didn’t change methods in DogRepository: Dog findDogByName(String name). I change that method to Dog findDogByCoolName(String name) and now it works.