GoLang与Java各自生成grpc代码流程介绍
GoLang与Java都支持gRPC服务的生成，下面将详细介绍它们各自生成gRPC代码的流程：
GoLang生成gRPC代码的流程
1.准备proto文件
准备好proto文件，它定义了gRPC服务所需要的消息结构和服务接口。
syntax = "proto3";
package greeter;
message HelloRequest {
string name = 1;
}
message HelloReply {
string message = 1;
}
service Greeter {
rpc SayHello (HelloRequest) returns (HelloReply) {}
}
2.使用protoc编译proto文件
使用官方提供的protoc工具，生成Go语言的gRPC代码。
protoc --go_out=plugins=grpc:. greeter.proto
其中，--go_out=plugins=grpc:参数表示生成gRPC代码，并指定输出目录为当前目录。
3.编写服务器代码
编写gRPC服务器代码，实现proto文件中定义的服务接口。
package main
import (
"context"
"log"
"net"
"google.golang.org/grpc"
pb "github.com/yourPackageName/yourProtoPackageName"
)
const (
port = ":50051"
)
type server struct {}
func (s *server) SayHello(ctx context.Context, in *pb.HelloRequest) (*pb.HelloReply, error) {
return &pb.HelloReply{Message: "Hello " + in.Name}, nil
}
func main() {
lis, err := net.Listen("tcp", port)
if err != nil {
log.Fatalf("failed to listen: %v", err)
}
s := grpc.NewServer()
pb.RegisterGreeterServer(s, &server{})
if err := s.Serve(lis); err != nil {
log.Fatalf("failed to serve: %v", err)
}
}
4.编写客户端代码
编写Golang gRPC客户端代码，调用proto文件中定义的服务接口。
package main
import (
"context"
"log"
"google.golang.org/grpc"
pb "github.com/yourPackageName/yourProtoPackageName"
)
const (
address = "localhost:50051"
)
func main() {
conn, err := grpc.Dial(address, grpc.WithInsecure())
if err != nil {
log.Fatalf("did not connect: %v", err)
}
defer conn.Close()
c := pb.NewGreeterClient(conn)
name := "world"
r, err := c.SayHello(context.Background(), &pb.HelloRequest{Name: name})
if err != nil {
log.Fatalf("could not greet: %v", err)
}
log.Printf("Greeting: %s", r.Message)
}
Java生成gRPC代码的流程
1.准备proto文件
准备好proto文件，它定义了gRPC服务所需要的消息结构和服务接口。
syntax = "proto3";
package greeter;
option java_package = "com.example.grpc";
option java_outer_classname = "GreeterProto";
option objc_class_prefix = "HLW";
message HelloRequest {
string name = 1;
}
message HelloReply {
string message = 1;
}
service Greeter {
rpc SayHello (HelloRequest) returns (HelloReply) {}
}
2.使用protobuf插件生成Java代码
使用protobuf插件，生成Java语言的gRPC代码。
protoc --plugin=protoc-gen-grpc-java=path/to/protoc-gen-grpc-java --grpc-java_out=path/to/output/directory --proto_path=path/to/proto/files --java_out=path/to/output/directory greeter.proto
其中，--grpc-java_out参数表示生成gRPC Java代码，--proto_path和--java_out参数表示proto文件和Java代码的输出目录。
3.编写服务器代码
编写gRPC服务器代码，实现proto文件中定义的服务接口。
package com.example.grpc;
import io.grpc.Server;
import io.grpc.ServerBuilder;
import io.grpc.stub.StreamObserver;
public class GreeterServer {
private int port = 50051;
private Server server;
private void start() throws Exception {
server = ServerBuilder.forPort(port)
.addService(new GreeterImpl())
.build()
.start();
System.out.println("Server started, listening on " + port);
Runtime.getRuntime().addShutdownHook(new Thread() {
@Override
public void run() {
System.err.println("*** shutting down gRPC server since JVM is shutting down");
GreeterServer.this.stop();
System.err.println("*** server shut down");
}
});
}
private void stop() {
if (server != null) {
server.shutdown();
}
}
private void blockUntilShutdown() throws Exception {
if (server != null) {
server.awaitTermination();
}
}
public static void main(String[] args) throws Exception {
final GreeterServer server = new GreeterServer();
server.start();
server.blockUntilShutdown();
}
static class GreeterImpl extends GreeterGrpc.GreeterImplBase {
@Override
public void sayHello(HelloRequest req, StreamObserver<HelloReply> responseObserver) {
HelloReply reply = HelloReply.newBuilder().setMessage("Hello " + req.getName()).build();
responseObserver.onNext(reply);
responseObserver.onCompleted();
}
}
}
4.编写客户端代码
编写Java gRPC客户端代码，调用proto文件中定义的服务接口。
package com.example.grpc;
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 GreeterClient {
private static final Logger logger = Logger.getLogger(GreeterClient.class.getName());
private final ManagedChannel channel;
private final GreeterGrpc.GreeterBlockingStub blockingStub;
public GreeterClient(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;
try {
response = blockingStub.sayHello(request);
} catch (StatusRuntimeException e) {
logger.log(Level.WARNING, "RPC failed: {0}", e.getStatus());
return;
}
logger.info("Greeting: " + response.getMessage());
}
public static void main(String[] args) throws Exception {
GreeterClient client = new GreeterClient("localhost", 50051);
try {
String user = "world";
client.greet(user);
} finally {
client.shutdown();
}
}
}
上述示例中，我们演示了使用GoLang与Java各自生成gRPC代码的流程，包括准备proto文件、使用相应的工具编译proto文件生成gRPC代码、编写服务器与客户端代码实现服务调用。