JAX-RS - Spring Boot vs without Spring Boot

Question

I want to use Spring boot with JAX-RS (Jersey Implementation). If we were not using Spring Boot, we could use the following code to register all the Rest service classes

@ApplicationPath("/myrest")
public class MyApplication extends Application {
    @Override
    public Set<Class<?>> getClasses() {
        Set<Class<?>> s = new HashSet<Class<?>>();
        s.add(HelloWorld.class);
        return s;
    }
}

This works fine in a Servlet 3.0 supported container.

But when we use Spring Boot with JAX-RS(Jersey) why do we have to extend from org.glassfish.jersey.server.ResourceConfig Why extending from javax.ws.rs.core.Application doesn't work?

Answer 1

But when we use Spring Boot with JAX-RS(Jersey) why do we have to extend from org.glassfish.jersey.server.ResourceConfig Why extending from javax.ws.rs.core.Application doesn't work?

Because Spring Boot uses the ResourceConfig type as the as a service that it injects into its auto configurer, namely the JerseyAutoConfiguration . If you look at the source code, you will see

@Autowired
private ResourceConfig config;

From there, Sprig Boot configures the app with that instance. If a ResourceConfig bean is not available in the Spring context, then not auto-configuration happens.