Vidocq Documentation
Version

Cassini strictly implements Jakarta RESTful Web Services 4.0. If your application is already standard (spec annotations, no proprietary API), the migration is mostly a swap of the Maven runtime coordinates. This page documents the gotchas and the mappings.

Cassini is at 0.4.0-SNAPSHOT. A production migration is premature until the first stable release ships. This page anticipates the path for evaluators.

From Jersey

Jersey Cassini Note

org.glassfish.jersey.server.ResourceConfig

jakarta.ws.rs.core.Application

Standard spec. Jersey-isms (packages(), register(Object)) become getClasses() / getSingletons().

org.glassfish.jersey.containers.grizzly2

cassini-chappe (reference transport) or cassini-jdk-http

Standard SeBootstrap.start(…​) instead of GrizzlyHttpServerFactory.

HK2 bridge (hk2-cdi-bridge)

cassini-cdi-vauban

Vauban resolves injection at build time, not via HK2.

jersey-mvc, jersey-bean-validation…​

No proprietary extensions

Cassini stays 100 % spec. Bean Validation must be wired manually (TODO post-1.0).

LoggingFeature

Standard ContainerRequestFilter + ContainerResponseFilter

Hand-written impl (10 lines — see usage).

 
// Before — Jersey + Grizzly
ResourceConfig config = new ResourceConfig().packages("com.example");
GrizzlyHttpServerFactory.createHttpServer(URI.create("http://0.0.0.0:8080/"), config);

// After — Cassini SE-Bootstrap
SeBootstrap.start(MyApplication.class, SeBootstrap.Configuration.builder()
    .host("0.0.0.0").port(8080).build()).toCompletableFuture().join();

From RESTEasy

RESTEasy Cassini Note

quarkus-resteasy-reactive

cassini-cdi-vauban

Equivalent build-time path, without Quarkus. Champollion replaces Quarkus’s JSON binding.

Vert.x transport

Chappe (cassini-chappe)

Native virtual threads, no event-loop. Different concurrency model — see internals.

Embedded Weld

Vauban (Lite) optional

Vauban is CDI 4.1 Lite, not Full. Verify you don’t rely on Full features (dynamic decorators, conversation scope, etc.).

jakarta.ws.rs.client (Client API)

cassini-client

Standard JAX-RS Client 4.0 now shipped (java.net.http + virtual threads). MicroProfile Rest Client is provided separately via Vidocq (Cyrano).

Pre/Post-matching filters

Same Jakarta REST 4.0

No change.

From Helidon REST

Helidon SE 4 exposes a custom API (HttpRouting, Handler). Helidon MP runs Jersey under the hood — migration is then equivalent to "from Jersey" above.

For Helidon SE → Cassini, you need to rewrite to standard JAX-RS annotations. Cassini is not a "fluent routing" engine — it is a Jakarta REST engine.

From CXF (JAX-RS)

CXF tracks the spec closely. Migration is largely a Maven-coordinate swap and replacing <jaxrs:server> Spring/Blueprint with SeBootstrap.start(…​).

JSON binding — heads-up

Jersey and RESTEasy default to Yasson or Jackson. Cassini goes through the JSON-B API; the Vidocq runtime, and the examples, use Champollion:

  • Static serialization: add champollion-codegen-apt to the build for new types.

  • Standard @JsonbProperty, @JsonbDateFormat, @JsonbTypeAdapter annotations supported.

  • Jackson annotations (@JsonProperty, @JsonIgnore…​) not supported — convert to JSON-B.

  • Unreadable JSON bodies NEW — with their default JSON-B providers, Jersey and RESTEasy answer 500 to a malformed or wrongly typed JSON body; for an empty body, Jersey answers 400 and RESTEasy passes null to the resource method. Cassini answers 400 in all these cases, after your own exception mappers — see Unreadable request entities.

Jakarta REST 4.0 annotations

All standard annotations are preserved. No expected change on user code if it is strictly spec-compliant.

Known pitfalls

  • Sub-resource locators (@Path on a method returning an instance): supported. Verify imports if the application used a proprietary variant.

  • @Suspended AsyncResponse: supported. SSE real-time streaming shipped with M2i; M2h (the true non-blocking milestone) was dropped as a non-goal — blocking on a virtual thread already yields the carrier (see TCK).

  • SSE: real-time streaming since M2i — events are flushed as they are emitted (no buffering), with client callbacks (spec §8.2) and broken-connection detection through Chappe.

  • JAX-RS Client: a standard client now ships in cassini-client (ClientBuilder.newClient(), java.net.http + virtual threads). Client-side multipart entities remain limited — use an external client for those in the meantime.

  • MicroProfile Config / Health / Metrics: wire via Vidocq Runtime (orchestrator) — Cassini alone does not configure MP.

See also