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Diffstat (limited to 'examples/cpp/metadata/greeter_client.cc')
-rw-r--r-- | examples/cpp/metadata/greeter_client.cc | 95 |
1 files changed, 95 insertions, 0 deletions
diff --git a/examples/cpp/metadata/greeter_client.cc b/examples/cpp/metadata/greeter_client.cc new file mode 100644 index 0000000000..8049438993 --- /dev/null +++ b/examples/cpp/metadata/greeter_client.cc @@ -0,0 +1,95 @@ +/* + * + * Copyright 2015 gRPC authors. + * + * Licensed under the Apache License, Version 2.0 (the "License"); + * you may not use this file except in compliance with the License. + * You may obtain a copy of the License at + * + * http://www.apache.org/licenses/LICENSE-2.0 + * + * Unless required by applicable law or agreed to in writing, software + * distributed under the License is distributed on an "AS IS" BASIS, + * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. + * See the License for the specific language governing permissions and + * limitations under the License. + * + */ + +#include <iostream> +#include <memory> +#include <string> + +#include <grpcpp/grpcpp.h> + +#ifdef BAZEL_BUILD +#include "examples/protos/helloworld.grpc.pb.h" +#else +#include "helloworld.grpc.pb.h" +#endif + +using grpc::Channel; +using grpc::ClientContext; +using grpc::Status; +using helloworld::HelloRequest; +using helloworld::HelloReply; +using helloworld::Greeter; + +class CustomHeaderClient { + public: + CustomHeaderClient(std::shared_ptr<Channel> channel) + : stub_(Greeter::NewStub(channel)) {} + + // Assembles the client's payload, sends it and presents the response back + // from the server. + std::string SayHello(const std::string& user) { + // Data we are sending to the server. + HelloRequest request; + request.set_name(user); + + // Container for the data we expect from the server. + HelloReply reply; + + // Context for the client. It could be used to convey extra information to + // the server and/or tweak certain RPC behaviors. + ClientContext context; + + // Setting custom metadata to be sent to the server + context.AddMetadata("custom-header", "Custom Value"); + + // Setting custom binary metadata + char bytes[8] = {'\0', '\1', '\2', '\3', + '\4', '\5', '\6', '\7'}; + context.AddMetadata("custom-bin", grpc::string(bytes, 8)); + + // The actual RPC. + Status status = stub_->SayHello(&context, request, &reply); + + // Act upon its status. + if (status.ok()) { + std::cout << "Client received initial metadata from server: " << context.GetServerInitialMetadata().find("custom-server-metadata")->second << std::endl; + std::cout << "Client received trailing metadata from server: " << context.GetServerTrailingMetadata().find("custom-trailing-metadata")->second << std::endl; + return reply.message(); + } else { + std::cout << status.error_code() << ": " << status.error_message() + << std::endl; + return "RPC failed"; + } + } + + private: + std::unique_ptr<Greeter::Stub> stub_; +}; + +int main(int argc, char** argv) { + // Instantiate the client. It requires a channel, out of which the actual RPCs + // are created. This channel models a connection to an endpoint (in this case, + // localhost at port 50051). We indicate that the channel isn't authenticated + // (use of InsecureChannelCredentials()). + CustomHeaderClient greeter(grpc::CreateChannel( + "localhost:50051", grpc::InsecureChannelCredentials())); + std::string user("world"); + std::string reply = greeter.SayHello(user); + std::cout << "Client received message: " << reply << std::endl; + return 0; +} |