diff --git a/Step_3.md b/Step_3.md deleted file mode 100644 index 7b03cdf585f..00000000000 --- a/Step_3.md +++ /dev/null @@ -1,82 +0,0 @@ -# Step-3: Implement a server. - -This step extends the generated server skeleton code to write a simple server -that provides the hello service. This introduces two new classes: - -- a service implementation [GreetingsImpl.java](src/main/java/ex/grpc/GreetingsImpl.java). - -- a server that hosts the service implementation and allows access over the network: [GreetingsServer.java](src/main/java/ex/grpc/GreetingsServer.java). - -## Service implementation - -[GreetingsImpl.java](src/main/java/ex/grpc/GreetingsImpl.java) -implements the behaviour we require of our GreetingService. There are a -number of important features of gRPC being used here: - -``` - public void hello(Helloworld.HelloRequest req, - StreamObserver responseObserver) { - Helloworld.HelloReply reply = Helloworld.HelloReply.newBuilder().setMessage( - "Hello " + req.getName()).build(); - responseObserver.onValue(reply); - responseObserver.onCompleted(); - } -``` - -- it provides a class `GreetingsImpl` that implements a generated interface `GreetingsGrpc.Greetings` -- `GreetingsGrpc.Greetings` declares the method `hello` that was declared in the proto [IDL](src/main/proto/helloworld.proto) -- `hello's` signature is typesafe: - hello(Helloworld.HelloRequest req, StreamObserver responseObserver) -- `hello` takes two parameters: - `Helloworld.HelloRequest`: the request - `StreamObserver`: a response observer, an interface to be called with the response value -- to complete the call - - the return value is constructed - - the responseObserver.onValue() is called with the response - - responseObserver.onCompleted() is called to indicate that no more work will done on the RPC. - - -## Server implementation - -[GreetingsServer.java](src/main/java/ex/grpc/GreetingsServer.java) shows the -other main feature required to provde the gRPC service; how to allow a service -implementation to be accessed from the network. - -``` - private void start() throws Exception { - server = NettyServerBuilder.forPort(port) - .addService(GreetingsGrpc.bindService(new GreetingsImpl())) - .build(); - server.startAsync(); - server.awaitRunning(5, TimeUnit.SECONDS); - } - -``` - -- it provides a class `GreetingsServer` that holds a `ServerImpl` that will run the server -- in the `start` method, `GreetingServer` binds the `GreetingsService` implementation to a port and begins running it -- there is also a `stop` method that takes care of shutting down the service and cleaning up when the program exits - -## Build it - -This is the same as before: our client and server are part of the same maven -package so the same command builds both. - -``` -$ mvn package -``` - -## Try them out - -We've added simple shell scripts to simplifying running the examples. Now -that they are built, you can run the server with: - -``` -$ ./run_greetings_server.sh -``` - -and in another terminal window confirm that it receives a message. - -``` -$ ./run_greetings_client.sh -```