protobuf
syntax = "proto3";
package com.example.grpc;
service Greeter {
rpc SayHello (HelloRequest) returns (HelloReply) {}
}
message HelloRequest {
string name = 1;
}
message HelloReply {
string message = 1;
}
import io.grpc.Server;
import io.grpc.ServerBuilder;
import io.grpc.stub.StreamObserver;
public class GreeterServer {
public static void main(String[] args) throws Exception {
Server server = ServerBuilder.forPort(50051)
.addService(new GreeterImpl())
.build()
.start();
System.out.println("Server started");
server.awaitTermination();
}
static class GreeterImpl extends GreeterGrpc.GreeterImplBase {
@Override
public void sayHello(HelloRequest request, StreamObserver<HelloReply> responseObserver) {
String message = "Hello, " + request.getName();
HelloReply reply = HelloReply.newBuilder().setMessage(message).build();
responseObserver.onNext(reply);
responseObserver.onCompleted();
}
}
}
import io.grpc.ManagedChannel;
import io.grpc.ManagedChannelBuilder;
public class GreeterClient {
public static void main(String[] args) {
ManagedChannel channel = ManagedChannelBuilder.forAddress("localhost", 50051).usePlaintext().build();
GreeterGrpc.GreeterBlockingStub stub = GreeterGrpc.newBlockingStub(channel);
HelloRequest request = HelloRequest.newBuilder().setName("John").build();
HelloReply reply = stub.sayHello(request);
System.out.println("Server replied: " + reply.getMessage());
channel.shutdown();
}
}
StreamObserver<HelloReply> responseObserver = new StreamObserver<HelloReply>() {
@Override
public void onNext(HelloReply reply) {
}
@Override
public void onError(Throwable t) {
System.out.println("Error occurred: " + t.getMessage());
}
@Override
public void onCompleted() {
}
};
@Override
public void sayHello(HelloRequest request, StreamObserver<HelloReply> responseObserver) {
try {
// ...
responseObserver.onNext(reply);
responseObserver.onCompleted();
} catch (Exception e) {
responseObserver.onError(e);
}
}
Server server = ServerBuilder.forPort(50051)
.build()
.start();
ManagedChannel channel = ManagedChannelBuilder.forAddress("localhost", 50051)
.usePlaintext()
.build();
