Package ratpack.core.service

Annotation Type DependsOn

@Documented
@Retention(RUNTIME)
@Target(TYPE)
@Inherited
public @interface DependsOn

Declares the other service types that services of the annotated type depend on.

This annotation is only effective when present on Service types.

 import ratpack.core.server.ServerConfig;
 import ratpack.core.server.RatpackServer;
 import ratpack.core.service.DependsOn;
 import ratpack.core.service.Service;
 import ratpack.core.service.StartEvent;
 import ratpack.core.service.StopEvent;

 import java.util.ArrayList;
 import java.util.List;

 import static java.util.Arrays.asList;
 import static org.junit.jupiter.api.Assertions.assertEquals;

 public class Example {

   private static final List<String> EVENTS = new ArrayList<>();

   private static class ServiceOne implements Service {
     @Override
     public void onStart(StartEvent event) throws Exception {
       EVENTS.add("one-start");
     }

     @Override
     public void onStop(StopEvent event) throws Exception {
       EVENTS.add("one-stop");
     }
   }

   @DependsOn(ServiceOne.class)
   private static class ServiceTwo implements Service {
     @Override
     public void onStart(StartEvent event) throws Exception {
       EVENTS.add("two-start");
     }

     @Override
     public void onStop(StopEvent event) throws Exception {
       EVENTS.add("two-stop");
     }
   }

   public static void main(String[] args) throws Exception {
     RatpackServer server = RatpackServer.of(s -> s
       .serverConfig(ServerConfig.embedded())
       .registryOf(r -> r
         // note: order of registration is irrelevant here
         .add(new ServiceOne())
         .add(new ServiceTwo())
       )
     );

     server.start();
     assertEquals(asList("one-start", "two-start"), EVENTS);

     server.stop();
     assertEquals(asList("one-start", "two-start", "two-stop", "one-stop"), EVENTS);
   }
 }
 

Since:

1.3

See Also:

ServiceDependencies

Required Element Summary

Required Elements

Modifier and Type	Required Element	Description
Class<?>[]	value	The types of services that services of the annotated type depend on.

Element Detail

value

Class<?>[] value

The types of services that services of the annotated type depend on.

Returns:

the types of services that services of the annotated type depend on.