参考博客：
Grpc项目集成到java方式调用实践
gRpc入门和springboot整合
java 中使用grpc java调用grpc服务

准备

因为需要生成代码，所以必备插件

安装后重启

依赖包

<?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>org.example</groupId>
    <artifactId>mistra</artifactId>
    <version>1.0-SNAPSHOT</version>

    <parent>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter-parent</artifactId>
        <version>2.7.10</version>
        <relativePath/>
    </parent>

    <properties>
        <maven.compiler.source>11</maven.compiler.source>
        <maven.compiler.target>11</maven.compiler.target>
        <protoc.version>3.25.2</protoc.version>
        <grpc.version>1.61.1</grpc.version>
        <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
    </properties>

    <dependencies>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-web</artifactId>
        </dependency>

        <dependency>
            <groupId>io.grpc</groupId>
            <artifactId>grpc-stub</artifactId>
            <version>${grpc.version}</version>

        </dependency>
        <dependency>
            <groupId>io.grpc</groupId>
            <artifactId>grpc-core</artifactId>
            <version>${grpc.version}</version>

        </dependency>

        <dependency>
            <groupId>com.google.protobuf</groupId>
            <artifactId>protobuf-java</artifactId>
            <version>3.25.2</version> <!-- 或者与你的 protoc.version 相匹配的版本 -->
        </dependency>
        <dependency>
            <groupId>io.grpc</groupId>
            <artifactId>grpc-netty</artifactId>
            <version>${grpc.version}</version>
        </dependency>
        <dependency>
            <!-- necessary for Java 9+ -->
            <groupId>org.apache.tomcat</groupId>
            <artifactId>annotations-api</artifactId>
            <version>6.0.53</version>
        </dependency>
    </dependencies>

    <build>
        <extensions>
            <extension>
                <groupId>kr.motd.maven</groupId>
                <artifactId>os-maven-plugin</artifactId>
                <version>1.6.2</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:${protoc.version}:exe:${os.detected.classifier}</protocArtifact>
                    <pluginId>grpc-java</pluginId>
                    <pluginArtifact>io.grpc:protoc-gen-grpc-java:${grpc.version}:exe:${os.detected.classifier}</pluginArtifact>
                </configuration>
                <executions>
                    <execution>
                        <goals>
                            <goal>compile</goal>
                            <goal>compile-custom</goal>
                        </goals>
                    </execution>
                </executions>
            </plugin>

            <plugin>
                <groupId>org.springframework.boot</groupId>
                <artifactId>spring-boot-maven-plugin</artifactId>
            </plugin>
        </plugins>
    </build>
</project>

在resource同级目录下创建一个包，包下创建proto文件

proto文件

syntax = "proto3";

package mistra;
//生成的java代码包名
option java_package = "org.example.mistra";
//创建的javaBean的文件名
option java_outer_classname = "MistraProto";
//option java_generic_services = true;
option java_multiple_files = true;

//请求
message MistraRequest {
  string id = 1;
  int64 timestamp = 2;
  string message = 3;
}

//响应
message MistraResponse {
  string message = 1;
}
//声明一个服务名称
service MistraService {
  rpc SendMessage(MistraRequest) returns (MistraResponse) {}
}

然后使用maven打包，在target目录下生成代码，复制到自己的目录下。
生成代码：

复制到自己目录下，再创建一个client和server，结构如下

client

package com.test.grpc.mistra.generate.client;

import com.test.grpc.mistra.generate.MistraRequest;
import com.test.grpc.mistra.generate.MistraResponse;
import com.test.grpc.mistra.generate.MistraServiceGrpc;
import io.grpc.ManagedChannel;
import io.grpc.ManagedChannelBuilder;

import java.util.concurrent.TimeUnit;

/**
 * @author清梦
 * @site www.xiaomage.com
 * @company xxx公司
 * @create 2024-06-04 21:59
 */
public class MistraClient {

    private final ManagedChannel channel;
    private final MistraServiceGrpc.MistraServiceBlockingStub blockingStub;


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

        blockingStub = MistraServiceGrpc.newBlockingStub(channel);
    }

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

    public void greet(String name) {
        MistraRequest request = MistraRequest.newBuilder().setId(name).build();
        MistraResponse response = blockingStub.sendMessage(request);
        System.out.println(response.getMessage());

    }

    public static void main(String[] args) throws InterruptedException {
        MistraClient client = new MistraClient("127.0.0.1", 8001);
        System.out.println("-------------------客户端开始访问请求-------------------");
        for (int i = 0; i < 10; i++) {
            client.greet("你若想生存，绝处也能缝生: " + i);
        }
    }
}

server

package com.test.grpc.mistra.generate.server;

import com.test.grpc.mistra.generate.MistraRequest;
import com.test.grpc.mistra.generate.MistraResponse;
import com.test.grpc.mistra.generate.MistraServiceGrpc;
import io.grpc.BindableService;
import io.grpc.Server;
import io.grpc.ServerBuilder;
import io.grpc.stub.StreamObserver;

import java.io.IOException;

/**
 * @author清梦
 * @site www.xiaomage.com
 * @company xxx公司
 * @create 2024-06-04 21:59
 */
public class MistraServer {

    private int port;

    private Server server;

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

        System.out.println("-------------------服务端服务已开启，等待客户端访问------------------");

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

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

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

    public static void main(String[] args) throws IOException, InterruptedException {
        final MistraServer server = new MistraServer();
        //启动服务
        server.start();
        //服务一直在线，不关闭
        server.blockUntilShutdown();
    }

    private class MistraSendMessage extends MistraServiceGrpc.MistraServiceImplBase {
        @Override
        public void sendMessage(MistraRequest request, StreamObserver<MistraResponse> responseObserver) {
            //业务实现代码
            System.out.println("server:" + request.getId());
            MistraResponse response = MistraResponse.newBuilder().setMessage("响应信息" + request.getMessage()).build();
            responseObserver.onNext(response);
            responseObserver.onCompleted();
        }
    }


}