How to use coroutine inside the router.route(“/api/*”).handler?

问题

I am trying to use coroutine inside the route handler lambda as follows:

  private suspend fun createRoutes(router: Router, auth: OAuth2Auth): Unit {


    val oauth2 = OAuth2AuthHandler.create(vertx, auth)
    val authz = KeycloakAuthorization.create()


    router.route().handler(LoggerHandler.create())

    router.route("/api/*").handler(oauth2)

     router.route("/api/greet").handler {

      println(RoleBasedAuthorization.create("ad-admins").match(it.user()))

      authz.getAuthorizations(it.user()).await()
    }

  }

The compiler complains on authz.getAuthorizations(it.user()).await() about Suspension functions can be called only within coroutine body. What am I doing wrong?

The whole code:

class MainVerticle : CoroutineVerticle() {

  private suspend fun initConfig(): JsonObject {
    val yamlConfigOpts = ConfigStoreOptions()
      .setFormat("yaml")
      .setType("file")
      .setConfig(JsonObject().put("path", "config.yaml"))

    val configRetrieverOpts = ConfigRetrieverOptions()
      .addStore(yamlConfigOpts)

    val configRetriever = ConfigRetriever.create(vertx, configRetrieverOpts)

    return configRetriever.config.await()
  }


  private suspend fun createJwtAuth(): OAuth2Auth =

    KeycloakAuth.discover(
      vertx,
      OAuth2Options()
        .setFlow(OAuth2FlowType.AUTH_CODE)
        .setClientID("svc")
        .setClientSecret("9d782e45-67e7-44b1-9b74-864f45f9a18f")
        .setSite("https://oic.dev.databaker.io/auth/realms/databaker")
    ).await()


  private suspend fun createRoutes(router: Router, auth: OAuth2Auth): Unit {


    val oauth2 = OAuth2AuthHandler.create(vertx, auth)
    val authz = KeycloakAuthorization.create()


    router.route().handler(LoggerHandler.create())

    router.route("/api/*").handler(oauth2)

    router.route("/api/greet").handler {

      println(RoleBasedAuthorization.create("ad-admins").match(it.user()))

      authz.getAuthorizations(it.user()).await()
    }

  }


  private suspend fun server(router: Router): HttpServer {
    val server = vertx.createHttpServer()

    return server.requestHandler(router)
      .listen(8080)
      .onSuccess {
        println("HTTP server started on port ${it.actualPort()}")
      }
      .onFailure {
        println("Failed to start the server. Reason ${it.message}")
      }
      .await()
  }


  override suspend fun start() {

    val router = Router.router(vertx)


    createRoutes(router, createJwtAuth())
    server(router)

  }

}

Hint: I am using Vertx 4.0.0 RC1

回答1:

The compiler because authz.getAuthorizations(it.user()).await() is not invoked in a suspended function: it is invoked from the Vert.x Web route handler.

You must wrap your invocation with launch:

router.route("/api/greet").handler {
  println(RoleBasedAuthorization.create("ad-admins").match(it.user()))
  launch {
    authz.getAuthorizations(it.user()).await()
  }
}

Given this code is defined in a CoroutineVerticle, the coroutine will be bound to the verticle context (and the code invoked on the verticle's event loop).

来源：https://stackoverflow.com/questions/64959205/how-to-use-coroutine-inside-the-router-route-api-handler

标签

java

kotlin

vert.x