java: grpc demo之代码生成插件

一、pom.xml

<?xml version="1.0" encoding="UTF-8"?>
<project xmlns="http://maven.apache.org/POM/4.0.0"
         xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
         xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
    <modelVersion>4.0.0</modelVersion>

    <groupId>cn.edu.tju</groupId>
    <artifactId>grpctest</artifactId>
    <version>1.0-SNAPSHOT</version>
    <properties>
        <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
        <maven.compiler.source>1.8</maven.compiler.source>
        <maven.compiler.target>1.8</maven.compiler.target>
        <grpc-version>1.54.0</grpc-version>
    </properties>

    <dependencies>
        <dependency>
            <groupId>io.grpc</groupId>
            <artifactId>grpc-core</artifactId>
            <version>${grpc-version}</version>
        </dependency>
        <dependency>
            <groupId>io.grpc</groupId>
            <artifactId>grpc-netty-shaded</artifactId>
            <version>${grpc-version}</version>
        </dependency>
        <dependency>
            <groupId>io.grpc</groupId>
            <artifactId>grpc-protobuf</artifactId>
            <version>${grpc-version}</version>
        </dependency>
        <dependency>
            <groupId>io.grpc</groupId>
            <artifactId>grpc-stub</artifactId>
            <version>${grpc-version}</version>
        </dependency>

        <dependency>
            <groupId>com.google.protobuf</groupId>
            <artifactId>protobuf-java</artifactId>
            <version>3.22.2</version>
        </dependency>
    </dependencies>


    <build>
        <extensions>
            <extension>
                <groupId>kr.motd.maven</groupId>
                <artifactId>os-maven-plugin</artifactId>
                <version>1.7.1</version>
            </extension>
        </extensions>
        <plugins>
            <plugin>
                <groupId>org.xolstice.maven.plugins</groupId>
                <artifactId>protobuf-maven-plugin</artifactId>
                <version>0.6.1</version>
                <configuration>
                    <protocArtifact>com.google.protobuf:protoc:3.21.7:exe:${os.detected.classifier}</protocArtifact>
                    <pluginId>grpc-java</pluginId>
                    <pluginArtifact>io.grpc:protoc-gen-grpc-java:1.54.0:exe:${os.detected.classifier}</pluginArtifact>
                </configuration>
                <executions>
                    <execution>
                        <goals>
                            <goal>compile</goal>
                            <goal>compile-custom</goal>
                        </goals>
                    </execution>
                </executions>
            </plugin>
        </plugins>
    </build>


</project>

二、在src\main\proto下创建proto文件，

syntax = "proto3";

option java_multiple_files = true;
option java_package = "cn.edu.tju.hello";
option java_outer_classname = "HelloWorldProto";
option objc_class_prefix = "TEST";

package helloworld;

message HelloRequest {
    string name = 1;
}

message HelloReply {
    string message = 1;
}
service Greeter{
    rpc greet(HelloRequest) returns (HelloReply);
}

三、mvn clean install ，生成java代码，并拷贝到source目录下的对应的package下
四、编写服务端的实现

package cn.edu.tju.hello;

import io.grpc.stub.StreamObserver;

public class MyGreeterImpl  extends GreeterGrpc.GreeterImplBase {

    @Override
    public void greet(HelloRequest req, StreamObserver<HelloReply> responseObserver) {
        HelloReply reply=null;
        reply = HelloReply.newBuilder().setMessage("hi ,"+req.getName()).build();


        responseObserver.onNext(reply);
        responseObserver.onCompleted();
    }

}

五、编写服务器

package cn.edu.tju.hello;


import io.grpc.Server;
import io.grpc.ServerBuilder;
import io.grpc.stub.StreamObserver;
import java.io.IOException;
import java.util.concurrent.TimeUnit;
import java.util.logging.Logger;


public class MyHelloServer {
    private static final Logger logger = Logger.getLogger(MyHelloServer.class.getName());

    private Server server;

    private void start() throws IOException {
        int port = 50059;
        server = ServerBuilder.forPort(port)
                .addService(new MyGreeterImpl())
                .build()
                .start();
        logger.info("服务器启动，监听端口:" + port);
        Runtime.getRuntime().addShutdownHook(new Thread() {
            @Override
            public void run() {
                System.err.println("正在关闭grpc服务......");
                try {
                    MyHelloServer.this.stop();
                } catch (Exception ex) {
                    System.out.println(ex.getMessage());
                }
                System.err.println("服务器已关闭");
            }
        });
    }

    private void stop() throws InterruptedException {
        if (server != null) {
            server.shutdown().awaitTermination(30, TimeUnit.SECONDS);
        }
    }


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


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


}

六、编写客户端

package cn.edu.tju.hello;




import io.grpc.Channel;
import io.grpc.ManagedChannel;
import io.grpc.ManagedChannelBuilder;
import io.grpc.StatusRuntimeException;
import java.util.concurrent.TimeUnit;
import java.util.logging.Level;
import java.util.logging.Logger;


public class MyHelloClient {
    private static final Logger logger = Logger.getLogger(MyHelloClient.class.getName());

    private final GreeterGrpc.GreeterBlockingStub blockingStub;

    public MyHelloClient(Channel channel) {
        blockingStub = GreeterGrpc.newBlockingStub(channel);
    }


    public void greet(String name) {
        logger.info("Will try to greet " + name +" ...");
        HelloRequest request = HelloRequest.newBuilder().setName(name).build();
        HelloReply response;
        try {
            response = blockingStub.greet(request);
        } catch (Exception ex) {
            logger.info(ex.getMessage());
            return;
        }
        logger.info("来自服务器的响应: " + response.getMessage());
    }


    public static void main(String[] args) throws Exception {
        String user = "爱因斯坦";
        String target = "localhost:50059";


        ManagedChannel channel = ManagedChannelBuilder.forTarget(target)
                .usePlaintext()
                .build();
        try {
            MyHelloClient client = new MyHelloClient(channel);
            client.greet(user);
        }catch (Exception ex){
            System.out.println(ex.getMessage());
        }
        finally {
            channel.shutdownNow().awaitTermination(5, TimeUnit.SECONDS);
        }
    }
}

七、启动服务器和客户端