RestBuilder violates Vert.x 4.3's handler ordering #134
Description
Description
Since vert.x 4.3 the order in which routes are registered is checked by io.vertx.ext.web.impl.RouteState.
Using rest.vertx with vert.x 4.3 can lead to an error in specific circumstances:
Exception in thread "main" java.lang.IllegalStateException: Cannot add [BODY] handler to route with [USER] handler at index 0
at io.vertx.ext.web.impl.RouteState.addContextHandler(RouteState.java:554)
at io.vertx.ext.web.impl.RouteImpl.handler(RouteImpl.java:143)
at com.zandero.rest.RestRouter.register(RestRouter.java:152)
at com.zandero.rest.RestRouter.register(RestRouter.java:70)
at com.zandero.rest.RestBuilder.getRouter(RestBuilder.java:497)
at com.zandero.rest.RestBuilder.build(RestBuilder.java:570)
This can be circumvented by setting the io.vertx.web.router.setup.lenient property to true, but even then a WARNING is logged.
As far as I could tell, this issue occurs
- When the request body is present in the function parameters
- When context (e.g.
User) is present in the function parameters
Resolution suggestions
From a cursory glance, the "weight" of a handler is determined by its type. As such, a PlatformHandler should have the highest "priority". So a possible solution would be to mark the custom handlers that are registered before the body handler as implements io.vertx.ext.web.handler.PlatformHandler.
If no marker interface is implemented, priority "USER" is assumed (lowest priority -> register last).
Steps to reproduce
Setup minimal vert.x app with a sample resource
fun main() {
val vertx = Vertx.vertx()
val router = RestBuilder(vertx)
.register(TestResource::class.java)
.build()
vertx.createHttpServer().requestHandler(router).listen(8080)
}
@Path("/test")
class TestResource {
@POST
fun postFoo(requestBody: String) = requestBody
@GET
fun getFoo(@Context user: User?) = "${user?.subject()}"
}Use vert.x 4.3+ and rest.vertx 1.1
dependencies {
implementation(platform("io.vertx:vertx-stack-depchain:4.3.3"))
implementation("io.vertx:vertx-web")
implementation("com.zandero:rest.vertx:1.1")
}Run app:
Exception in thread "main" java.lang.IllegalStateException: Cannot add [BODY] handler to route with [USER] handler at index 0
at io.vertx.ext.web.impl.RouteState.addContextHandler(RouteState.java:554)
at io.vertx.ext.web.impl.RouteImpl.handler(RouteImpl.java:143)
at com.zandero.rest.RestRouter.register(RestRouter.java:152)
at com.zandero.rest.RestRouter.register(RestRouter.java:70)
at com.zandero.rest.RestBuilder.getRouter(RestBuilder.java:497)
at com.zandero.rest.RestBuilder.build(RestBuilder.java:570)
at rest.vertx.repro.AppKt.main(App.kt:10)
at rest.vertx.repro.AppKt.main(App.kt)