quarkus

REST Endpoints

• Annotate resource classes with @Path and use @GET, @POST, @PUT, @DELETE for HTTP methods.
• Return String or Response for plain text. Add rest-jackson or rest-jsonb for JSON serialization.
• Use @RestParam for parameter binding, or omit the annotation entirely — RESTEasy Reactive infers parameter types from the method signature.
• For async endpoints, return Uni<T> or Multi<T> from Mutiny.
• For custom status codes, return RestResponse<T> (type-safe) or Response.
• @GET endpoints typically do NOT need @Transactional.
• Inject services with @Inject. Keep business logic out of resource classes.

Filters and Exception Mapping

• Use @ServerRequestFilter and @ServerResponseFilter on methods for simple filters.
• Use @ServerExceptionMapper on methods in resource classes to map exceptions to responses.
• Both approaches are simpler than implementing ContainerRequestFilter or ExceptionMapper<T>.

Testing

• Use @QuarkusTest with REST Assured for endpoint testing.
• Use @TestHTTPEndpoint(MyResource.class) to avoid hardcoding paths.
• Test both success and error paths.
• Test classes and methods can be package-private (JUnit 5 does not require public).

Common Pitfalls

• Resource classes default to @Singleton in RESTEasy Reactive. Use @RequestScoped if you need per-request state.
• @Path on class + @Path on methods combine (e.g. /api + /items = /api/items).
• REST Reactive (this extension) is NOT compatible with RESTEasy Classic — do not mix them.