gRPC HelloWorld java版

1. 创建一个maven项目

2. 加入依赖

3. 编写proto文件

4. 编写服务端文件， 和客户端文件

package org;

import io.grpc.Server;
import io.grpc.ServerBuilder;
import io.grpc.examples.helloworld.GreeterGrpc;
import io.grpc.examples.helloworld.HelloReply;
import io.grpc.examples.helloworld.HelloRequest;
import io.grpc.stub.StreamObserver;

import java.io.IOException;

/**
 *
 * Created by saxing on 2018/5/30.
 */
public class HelloWorldServer {

    private int port = 23333;
    private Server server;

    private void start() throws IOException{
        server = ServerBuilder.forPort(port)
                .addService(new GreeterImpl())
                .build()
                .start();

        System.out.println("service start...");

        Runtime.getRuntime().addShutdownHook(new Thread(){
            @Override
            public void run() {
                System.err.println("*** shutting down gRPC server since JVM is shutting down");
                HelloWorldServer.this.stop();
                System.err.println("*** server shut down");
            }
        });
    }

    private void stop(){
        if (server != null){
            server.shutdown();
        }
    }

    public static void main(String[] args) throws InterruptedException, IOException {
        final HelloWorldServer server = new HelloWorldServer();
        server.start();
        server.blockUtilShutdown();
    }

    private void blockUtilShutdown() throws InterruptedException{
        if (server != null){
            server.awaitTermination();
        }
    }

    private class GreeterImpl extends GreeterGrpc.GreeterImplBase{

        @Override
        public void sayHello(HelloRequest req, StreamObserver<HelloReply> responseObserver){
            System.out.println("service: " + req.getName());
            HelloReply reply = HelloReply.newBuilder().setMessage(("Hello: " + req.getName())).build();
            responseObserver.onNext(reply);
            responseObserver.onCompleted();
        }
    }
}

package org;

import io.grpc.ManagedChannel;
import io.grpc.ManagedChannelBuilder;
import io.grpc.examples.helloworld.GreeterGrpc;
import io.grpc.examples.helloworld.HelloReply;
import io.grpc.examples.helloworld.HelloRequest;

import java.util.concurrent.TimeUnit;

/**
 *
 * Created by saxing on 2018/5/30.
 */
public class HelloWorldClient {

    private final ManagedChannel channel;
    private final GreeterGrpc.GreeterBlockingStub blockingStub;

    public HelloWorldClient(String host, int port) {
        channel = ManagedChannelBuilder.forAddress(host, port)
                .usePlaintext(true)
                .build();

        blockingStub = GreeterGrpc.newBlockingStub(channel);
    }

    public void shutdown() throws InterruptedException {
        channel.shutdown().awaitTermination(5, TimeUnit.SECONDS);
    }

    public void greet(String name){
        HelloRequest request = HelloRequest.newBuilder().setName(name).build();
        HelloReply response = blockingStub.sayHello(request);
        System.out.println(response.getMessage());
    }

    public static void main(String[] args) throws InterruptedException {
        HelloWorldClient client = new HelloWorldClient("127.0.0.1", 23333);
        for (int i = 0; i < 5; i++) {
            client.greet("world: " + i);
        }
        client.shutdown();
    }
}

5. 运行测试结果

 

更多详细参考：

https://github.com/grpc/grpc-java/tree/master/examples/src/main/java/io/grpc/examples