Vertx web routes and Reactive Pg Client issue in Quarkus - vert.x

Question

The application is based on the following stack:
Quarkus 1.5.0
Extensions: vertx-web, reactive-pgclient
The complete codes is here.
I created a Router by #Observes Router.
#ApplicationScoped
public class RoutesObserver {
#Inject PostsHandlers handlers;
public void route(#Observes Router router) {
router.get("/posts").produces("application/json").handler(handlers::getAll);
router.post("/posts").consumes("application/json").handler(handlers::save);
router.get("/posts/:id").produces("application/json").handler(handlers::get);
router.put("/posts/:id").consumes("application/json").handler(handlers::update);
router.delete("/posts/:id").handler(handlers::delete);
router.get("/hello").handler(rc -> rc.response().end("Hello from my route"));
}
}
And extracted the handlers into a standalone bean.
#ApplicationScoped
class PostsHandlers {
private static final Logger LOGGER = Logger.getLogger(PostsHandlers.class.getSimpleName());
PostRepository posts;
ObjectMapper objectMapper;
#Inject
public PostsHandlers(PostRepository posts, ObjectMapper objectMapper) {
this.posts = posts;
this.objectMapper = objectMapper;
}
public void getAll(RoutingContext rc) {
this.posts.findAll().thenAccept(
data -> rc.response()
.write(toJson(data))
.end()
);
}
//... other methods.
}
And the PostRepository used the Java 8 CompletionStage API.
#ApplicationScoped
public class PostRepository {
private static final Logger LOGGER = LoggerFactory.getLogger(PostRepository.class);
private final PgPool client;
#Inject
public PostRepository(PgPool _client) {
this.client = _client;
}
public CompletionStage<List<Post>> findAll() {
return client.query("SELECT * FROM posts ORDER BY id ASC")
.execute()
.thenApply(rs -> StreamSupport.stream(rs.spliterator(), false)
.map(this::from)
.collect(Collectors.toList())
);
}
And when I ran this application and tried to access the /posts. It is frozen and no response printed.

Answer 1

When using the write method, you need to set (beforehand) the content-length header.
There are a several approaches to handle this:
You can use .end(toJson(data)) instead of write(...).end() - it will computed the length automatically
You can use .putHeader("transfer-encoding", "chunked") and you write(...).end() - if you plan to retrieve multiple results, it's interesting as it writes each chunk to the client one by one, avoiding sending a large payload in one go
you can set the content-length as in:
String result = toJson(data);
rc.response()
.putHeader("content-length", Long.toString(result.length()))
.write(result)
.end();