Spring Boot: Jersey ResourceConfig needs annotating?

Question

I am just getting started with Spring Boot and I wanted to implement a ResourceConfig and I finding some conflicting ideas.

Take the following:

@Component
public class JerseyExampleConfig extends ResourceConfig {

The above is annotated with COMPONENT:

@Configuration
public class JerseyExampleConfig extends ResourceConfig {

Which one is correct?

I thought annotating with Configuration would be the correct way but it appears that the Component is used in examples.

What's the difference?

Answer 1

The documentation suggests @Component:

To get started with Jersey 2.x just include the spring-boot-starter-jersey as a dependency and then you need one @Bean of type ResourceConfig in which you register all the endpoints:

@Component
public class JerseyConfig extends ResourceConfig {

    public JerseyConfig() {
        register(Endpoint.class);
    }
}

The documentation also says the following:

You can also register an arbitrary number of beans implementing ResourceConfigCustomizer for more advanced customizations.

All the registered endpoints should be @Components with HTTP resource annotations (@GET etc.), e.g.

@Component
@Path("/hello")
public class Endpoint {

    @GET
    public String message() {
        return "Hello";
    }
}

Since the Endpoint is a Spring @Component its lifecycle is managed by Spring and you can @Autowired dependencies and inject external configuration with @Value. The Jersey servlet will be registered and mapped to /* by default. You can change the mapping by adding @ApplicationPath to your ResourceConfig.