grpc java helloworld 简单demo实现

本是古典何须时尚 2022-07-18 00:28 217阅读 0赞

## 写在前面 ##

最近google发布了grpc1.0，之前一直关注过grpc，数据交互使用了protocol buffer,相比之前使用的hession和json序列化方式性能应该提升不少，所有先搞一个grpc的hello world跑一下,项目使用maven搭建，并使用idea开发。

## 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 ###

配置了protobuf 插件后，可以自动将.proto文件生成对应的java代码

<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 ##

![这里写图片描述][20160903104442056]

## 项目运行结果 ##

### 服务端 ###

![这里写图片描述][20160903104620932]

### 客户端 ###

![这里写图片描述][20160903104639014]

[20160903104442056]: /images/20220717/987d833d86d948a091e7f965ca41efb6.png
[20160903104620932]: /images/20220717/846e9cbd63a44636bffa5e16b103a784.png
[20160903104639014]: /images/20220717/51fe37421aa44ad7aed7aa56fb8026f8.png