Migration · Vidocq

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

From Jersey

Jersey Cassini Note

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).

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

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.

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 delegates to 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.

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; full chunked streaming is on milestone M2h (see TCK).
SSE backpressure: CassiniSseEventSink buffers in 0.1.0 — real-time streaming arrives in M2i.
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.