grpc java helloworld 简单demo实现

写在前面

使用idea创建maven项目，添加pom配置

添加grpc1.0 maven依赖

<dependency>
<groupId>io.grpc</groupId>
<artifactId>grpc-netty</artifactId>
<version>1.0.0</version>
</dependency>
<dependency>
<groupId>io.grpc</groupId>
<artifactId>grpc-protobuf</artifactId>
<version>1.0.0</version>
</dependency>
<dependency>
<groupId>io.grpc</groupId>
<artifactId>grpc-stub</artifactId>
<version>1.0.0</version>
</dependency>

配置protobuf maven插件

<build>
<extensions>
<extension>
<groupId>kr.motd.maven</groupId>
<artifactId>os-maven-plugin</artifactId>
<version>1.4.1.Final</version>
</extension>
</extensions>
<plugins>
<plugin>
<groupId>org.xolstice.maven.plugins</groupId>
<artifactId>protobuf-maven-plugin</artifactId>
<version>0.5.0</version>
<configuration>
<protocArtifact>com.google.protobuf:protoc:3.0.0:exe:${os.detected.classifier}</protocArtifact>
<pluginId>grpc-java</pluginId>
<pluginArtifact>io.grpc:protoc-gen-grpc-java:1.0.0:exe:${os.detected.classifier}</pluginArtifact>
</configuration>
<executions>
<execution>
<goals>
<goal>compile</goal>
<goal>compile-custom</goal>
</goals>
</execution>
</executions>
</plugin>
</plugins>
</build>

编写proto文件 helloworld.proto

syntax = "proto3";

option java_multiple_files = true;
option java_package = "io.grpc.examples.helloworld";
option java_outer_classname = "HelloWorldProto";
option objc_class_prefix = "HLW";

package helloworld;

// The greeting service definition.
service Greeter {
// Sends a greeting
rpc SayHello (HelloRequest) returns (HelloReply) {}
}

// The request message containing the user's name.
message HelloRequest {
string name = 1;
}

// The response message containing the greetings
message HelloReply {
string message = 1;
}

编写grpc 服务端HelloWorldServer.java

package com;

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;

public class HelloWorldServer {

private int port = 50051;
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();
}
}

// block 一直到退出程序
private void blockUntilShutdown() throws InterruptedException {
if (server != null) {
server.awaitTermination();
}
}

public static void main(String[] args) throws IOException, InterruptedException {

final HelloWorldServer server = new HelloWorldServer();
server.start();
server.blockUntilShutdown();
}

// 实现 定义一个实现服务接口的类
private class GreeterImpl extends GreeterGrpc.GreeterImplBase {

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();
}
}
}

编写grpc 客户端 HelloWorldClient.java

package com;

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;

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",50051);
for(int i=0;i<5;i++){
client.greet("world:"+i);
}

}
}

项目完整结构

项目运行结果

服务端

客户端