[brandur]

🤖 Move worker configuration and startup onto Client. Workers now holds typed handler registrations, and Client.start() returns an AutoCloseable RunHandle with stop(), stopAndCancel(), and runtime queue/periodic controls.

var workers = new Workers().add(email, context -> sendEmail(context.args()));
var client = Client.builder(database).queue("default", 10).workers(workers).build();
try (var run = client.start()) {
  application.awaitStop();
}

Subscriptions and event types also move to Client, so callers can subscribe before startup and retain subscriptions across restarts. A client permits only one active run, including while a timed-out stop drains. Successful shutdown allows restart with the same client ID; stopping an old handle cannot affect a later run. Insert-only clients still need no lifecycle calls.

Update the existing runtime tests, conformance adapter, examples, API inventory, and changelog. Add regression coverage for concurrent starts, startup failure recovery, registry snapshots, local insert wakeups, subscriptions, restarts, and both stop modes.

Validation:

• make lint/java test/java/tools test/java/sqlite check/java/package
• make test/java/postgres against a disposable local database
• Compiled and ran the README quick start against SQLite
• Exercised the conformance adapter with pre-start jobs, completion events, and two start/stop cycles

[brandur]

@bgentry Found a piece of the Java API that was weirdly inconsistent here (instead of getting a RunHandle that you'd called stop on like in Rust, in Java you got a Workers instead and called stop on that, which is fairly odd because Workers does something else in every other language.

I'm going to do a quick patch here while we can still break things without much trouble:

Language	Startup	Shutdown
Go	Client.Start()	Client.Stop() / StopAndCancel()
Ruby	Client#start	On Client
JavaScript	client.start() → RunHandle	On RunHandle
Rust	client.start() → RunHandle	On RunHandle
Java, previously	Workers.Builder.start() → Workers	On Workers
Java, updated	client.start() → RunHandle	RunHandle.stop() / stopAndCancel() / close()