Play with grpc - communication between different programming languages

1 brief introduction gRPC How to connect between different languages

2 install Protoc buffer

Download link ：https://github.com/protocolbuffers/protobuf/releases

Windows I suggest downloading the executable file directly ：

Put it into the specified directory after downloading , Configure environment variables ：

verification ：

If the following exception occurs ：

Solution ：

hold protoc.exe copy to C:\Windows\System32

3 Go Use gRPC Conduct Go Communication between programs

Project structure ：

Download dependency ：

go get google.golang.org/protobuf/runtime/[email protected]
go get google.golang.org/grpc
go get google.golang.org/protobuf

go.mod file ：

module grpc_go

go 1.16

require (
   google.golang.org/grpc v1.43.0 // indirect
   google.golang.org/protobuf v1.26.0 // indirect
)

protoc file ：

syntax = "proto3";  // Specify the syntax format 
package proto;  // Specify the generated package name 

option java_package = "org.ymx.proto";
option go_package = "/";

//  Definition gRPC Service interface 
service HelloService {
  //  Specific methods of interface 
  rpc SayHello(HelloRequest) returns (HelloReply) {}
}

//  The request parameter type of the interface 
message HelloRequest {
  string name = 1;
}

//  The response parameter type of the interface 
message HelloReply {
  string message = 1;
}

To proto Compile under directory , After compilation, the specified go file ：

C:\Users\17122\Desktop\grpc_demo\grpc_go\protoc> protoc -I . --go_out=plugins=grpc:. hello.proto

If there is an anomaly ：

'protoc-gen-go'  Not an internal or external command , It's not a runnable program  
 Or batch files . 
--go_out: protoc-gen-go: Plugin failed with status code 1.

Solution ：

Download this project , To protoc-gen-go Under the table of contents ,go build -o protoc-gen-go.exe main.go , Generate protoc-gen-go.exe file

then protoc-gen-go.exe copy to C:\Windows\System32

grpc client ,main.go

package main

import (
   "context"
   "fmt"
   "google.golang.org/grpc"
   _ "grpc_go/proto"
   __ "grpc_go/proto"
   "log"
)

func main() {
    
   //1  To configure grpc The port of the server is used as the listening port of the client 
   conn, err := grpc.Dial(":6666", grpc.WithInsecure())
   if err != nil {
    
      log.Fatalf(" Monitoring the server  : %v\n", err)
   }
   defer conn.Close()
   //2  Instantiation  UserInfoService  Client of service 
   client := __.NewHelloServiceClient(conn)
   //3  call grpc service 
   req := new (__.HelloRequest)
   req.Name = "YMX"
   resp, err := client.SayHello(context.Background(), req)
   if err != nil {
    
      log.Fatalf(" Request error  : %v\n", err)
   }
   fmt.Printf(" Response content  : %v\n", resp)
}

grpc Server side ,main.go

import (
   "context"
   "fmt"
   "google.golang.org/grpc"
   __ "grpc_go/proto"
   "log"
   "net"
)

// Define the server   Realization   Agreed interface 
type HelloServiceServer struct{
    }

var u = HelloServiceServer{
    }

// Realization  interface
func (s *HelloServiceServer) SayHello(ctx context.Context, req *__.HelloRequest) (resp *__.HelloReply, err error) {
    
   name := req.Name
   if name == "YMX" {
    
      resp = &__.HelloReply{
    Message: "Hello YMX"}
   } else {
    
      resp = &__.HelloReply{
    Message: "Hi NoYMX"}
   }
   err = nil
   return resp, nil
}

// Start the service 
func main() {
    
   //1  Add listening port 
   port := ":6666"
   l, err := net.Listen("tcp", port)
   if err != nil {
    
      log.Fatalf(" Port listening error  : %v\n", err)
   }
   fmt.Printf(" Monitoring ： %s  port \n", port)
   //2  start-up grpc service 
   s := grpc.NewServer()
   //3  take UserInfoService Service registered to gRPC in , Note that the second parameter is a variable of interface type , You need to take the address to pass the parameter 
   __.RegisterHelloServiceServer(s, &u)
   s.Serve(l)
}

Start the server and client , To test ：

4 Java Use gRPC Conduct Java Communication between programs

Project structure ：

pom rely on

<?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.ymx</groupId>
    <artifactId>grpc_java</artifactId>
    <version>1.0-SNAPSHOT</version>

    <dependencies>
        <dependency>
            <groupId>com.google.protobuf</groupId>
            <artifactId>protobuf-java</artifactId>
            <version>3.5.1</version>
        </dependency>
        <dependency>
            <groupId>io.grpc</groupId>
            <artifactId>grpc-all</artifactId>
            <version>1.43.0</version>
        </dependency>
    </dependencies>

    <properties>
        <maven.compiler.source>8</maven.compiler.source>
        <maven.compiler.target>8</maven.compiler.target>
    </properties>
    <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>

</project>

protoc The contents of the document ：

syntax = "proto3";  // Specify the syntax format 
package proto;  // Specify the generated package name ;

option java_multiple_files = true;
option java_package = "org.ymx.proto";
option go_package = "/";
option java_outer_classname = "Hello";
option objc_class_prefix = "YMX";


service HelloService {
  rpc SayHello(HelloRequest) returns (HelloReply) {}
}

message HelloRequest {
  string name = 1;
}

message HelloReply {
  string message = 1;
}

Compile , The first use of protobuf Compile ：

And then reuse it maven Compile ：

grpc Server code ：

package org.ymx;

import io.grpc.ServerBuilder;
import io.grpc.stub.StreamObserver;
import org.ymx.proto.HelloReply;
import org.ymx.proto.HelloRequest;
import org.ymx.proto.HelloServiceGrpc;

import java.io.IOException;

/** * @desc: grpc Server side  * @author: YanMingXin * @create: 2021/12/18-14:52 **/
public class Server {
    

    private final static int port = 5555;
    private io.grpc.Server server;

    private void start() throws IOException {
    
        server = ServerBuilder.forPort(port)
                .addService(new HelloServiceImpl())
                .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");
                Server.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 Server server = new Server();
        server.start();
        server.blockUntilShutdown();
    }

    /** *  Realization   Define a class that implements the service interface  */
    private class HelloServiceImpl extends HelloServiceGrpc.HelloServiceImplBase {
    

        @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();
        }
    }
}

grpc Client code ：

package org.ymx;

import io.grpc.ManagedChannel;
import io.grpc.ManagedChannelBuilder;
import org.ymx.proto.HelloReply;
import org.ymx.proto.HelloRequest;
import org.ymx.proto.HelloServiceGrpc;

import java.util.concurrent.TimeUnit;

/** * @desc: grpc client  * @author: YanMingXin * @create: 2021/12/18-14:52 **/
public class Client {
    

    private final ManagedChannel channel;
    private final HelloServiceGrpc.HelloServiceBlockingStub blockingStub;

    public Client(String host, int port) {
    
        channel = ManagedChannelBuilder.forAddress(host, port)
                .usePlaintext()
                .build();
        blockingStub = HelloServiceGrpc.newBlockingStub(channel);
    }

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

    public void hello(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) {
    
        Client client = new Client("127.0.0.1", 5555);
        for (int i = 0; i < 5; i++) {
    
            if (i < 3) {
    
                client.hello("ZS");
            } else {
    
                client.hello("YMX");
            }
        }
    }
}

Start the test ：

5 Use gRPC Conduct Go and Java Communication between programs

5.1 Use Java As a server ,Go As a client

Modify the client port ：

Java Server code , The rest of the code doesn't change ：

/** * @desc: grpc Server side  * @author: YanMingXin * @create: 2021/12/18-14:52 **/
public class Server {
    

    private final static int port = 5555;
    private io.grpc.Server server;

    private void start() throws IOException {
    
        server = ServerBuilder.forPort(port)
                .addService(new HelloServiceImpl())
                .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");
                Server.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 Server server = new Server();
        server.start();
        server.blockUntilShutdown();
    }

    /** *  Realization   Define a class that implements the service interface  */
    private class HelloServiceImpl extends HelloServiceGrpc.HelloServiceImplBase {
    

        @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();
        }
    }
}

Go Client code , The rest of the code doesn't change ：

import (
   "context"
   "fmt"
   "google.golang.org/grpc"
   _ "grpc_go/proto"
   __ "grpc_go/proto"
   "log"
)

func main() {
    
   //1  To configure grpc The port of the server is used as the listening port of the client 
   conn, err := grpc.Dial(":5555", grpc.WithInsecure())
   if err != nil {
    
      log.Fatalf(" Monitoring the server  : %v\n", err)
   }
   defer conn.Close()
   //2  Instantiation  UserInfoService  Client of service 
   client := __.NewHelloServiceClient(conn)
   //3  call grpc service 
   req := new (__.HelloRequest)
   req.Name = "YMX"
   resp, err := client.SayHello(context.Background(), req)
   if err != nil {
    
      log.Fatalf(" Request error  : %v\n", err)
   }
   fmt.Printf(" Response content  : %v\n", resp)
}

test ：

5.2 Use Go As a server ,Java As a client

Modify the client port ：

Go Server code , The rest of the code doesn't change ：

import (
   "context"
   "fmt"
   "google.golang.org/grpc"
   __ "grpc_go/proto"
   "log"
   "net"
)

// Define the server   Realization   Agreed interface 
type HelloServiceServer struct{
    }

var u = HelloServiceServer{
    }

// Realization  interface
func (s *HelloServiceServer) SayHello(ctx context.Context, req *__.HelloRequest) (resp *__.HelloReply, err error) {
    
   name := req.Name
   if name == "YMX" {
    
      resp = &__.HelloReply{
    Message: "Hello YMX"}
   } else {
    
      resp = &__.HelloReply{
    Message: "Hi NoYMX"}
   }
   err = nil
   return resp, nil
}

// Start the service 
func main() {
    
   //1  Add listening port 
   port := ":6666"
   l, err := net.Listen("tcp", port)
   if err != nil {
    
      log.Fatalf(" Port listening error  : %v\n", err)
   }
   fmt.Printf(" Monitoring ： %s  port \n", port)
   //2  start-up grpc service 
   s := grpc.NewServer()
   //3  take UserInfoService Service registered to gRPC in , Note that the second parameter is a variable of interface type , You need to take the address to pass the parameter 
   __.RegisterHelloServiceServer(s, &u)
   s.Serve(l)
}

Java Client code , The rest of the code doesn't change ：

/** * @desc: grpc client  * @author: YanMingXin * @create: 2021/12/18-14:52 **/
public class Client {
    

    private final ManagedChannel channel;
    private final HelloServiceGrpc.HelloServiceBlockingStub blockingStub;

    public Client(String host, int port) {
    
        channel = ManagedChannelBuilder.forAddress(host, port)
                .usePlaintext()
                .build();
        blockingStub = HelloServiceGrpc.newBlockingStub(channel);
    }

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

    public void hello(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) {
    
        Client client = new Client("127.0.0.1", 6666);
        for (int i = 0; i < 5; i++) {
    
            if (i < 3) {
    
                client.hello("ZS");
            } else {
    
                client.hello("YMX");
            }
        }
    }
}

test ：

6 summary

• Deposit protoc Try to use proto name

Source code acquisition method ： Pay attention to the official account below. , reply 【0701】