== Vert.x gRPC/IO Server

Vert.x gRPC/IO Server extends the Vert.x gRPC server with _grpc-java_ integration.

This server provides compatibility with the _grpc-java_ generated stub approach with a service bridge.

=== Using Vert.x gRPC/IO Server

To use Vert.x gRPC/IO Server, add the following dependency to the _dependencies_ section of your build descriptor:

* Maven (in your `pom.xml`):

[source,xml,subs="+attributes"]
----
<dependency>
  <groupId>io.vertx</groupId>
  <artifactId>vertx-grpcio-server</artifactId>
  <version>5.0.0.CR3</version>
</dependency>
----

* Gradle (in your `build.gradle` file):

[source,groovy,subs="+attributes"]
----
dependencies {
  compile 'io.vertx:vertx-grpcio-server:5.0.0.CR3'
}
----

=== Service bridge

The Vert.x gRPC Server can bridge a gRPC service to use with _grpc-java_ generated server classes.

[source,java]
----
GrpcIoServer grpcServer = GrpcIoServer.server(vertx);

GreeterGrpc.GreeterImplBase service = new GreeterGrpc.GreeterImplBase() {
  @Override
  public void sayHello(HelloRequest request, StreamObserver<HelloReply> responseObserver) {
    responseObserver.onNext(HelloReply.newBuilder().setMessage("Hello " + request.getName()).build());
    responseObserver.onCompleted();
  }
};

// Bind the service bridge in the gRPC server
GrpcIoServiceBridge serverStub = GrpcIoServiceBridge.bridge(service);
serverStub.bind(grpcServer);

// Start the HTTP/2 server
vertx.createHttpServer(options)
  .requestHandler(grpcServer)
  .listen();
----

The bridge supports deadline automatic cancellation: when a gRPC request carrying a timeout is received, a deadline is associated with the `io.grpc.Context` an can be obtained from the current context. This deadline automatically cancels the request in progress when its associated timeout fires.