# 安裝protobuf編譯器
brew install protobuf
# 安裝Go的protobuf插件
go install google.golang.org/protobuf/cmd/protoc-gen-go@latest
go install google.golang.org/grpc/cmd/protoc-gen-go-grpc@latest

syntax = "proto3";
package user;
option go_package = "./user";
// 用戶服務(wù)
service UserService {
  // 獲取用戶信息
  rpc GetUser(GetUserRequest) returns (GetUserResponse);
  // 創(chuàng)建用戶
  rpc CreateUser(CreateUserRequest) returns (CreateUserResponse);
  // 流式獲取用戶列表
  rpc ListUsers(ListUsersRequest) returns (stream ListUsersResponse);
}
// 獲取用戶請求
message GetUserRequest {
  int32 id = 1;
}
// 獲取用戶響應(yīng)
message GetUserResponse {
  User user = 1;
}
// 創(chuàng)建用戶請求
message CreateUserRequest {
  string name = 1;
  string email = 2;
}
// 創(chuàng)建用戶響應(yīng)
message CreateUserResponse {
  User user = 1;
}
// 列表用戶請求
message ListUsersRequest {
  int32 page = 1;
  int32 page_size = 2;
}
// 列表用戶響應(yīng)
message ListUsersResponse {
  User user = 1;
}
// 用戶信息
message User {
  int32 id = 1;
  string name = 2;
  string email = 3;
}

# 生成Go代碼
protoc --go_out=. --go-grpc_out=. proto/user.proto

package main
import (
	"context"
	"fmt"
	"log"
	"net"
	"google.golang.org/grpc"
	pb "your-project/user"
)
// 實現(xiàn)UserService服務(wù)
type userService struct {
	pb.UnimplementedUserServiceServer
}
// GetUser實現(xiàn)
func (s *userService) GetUser(ctx context.Context, req *pb.GetUserRequest) (*pb.GetUserResponse, error) {
	// 模擬從數(shù)據(jù)庫獲取用戶
	user := &pb.User{
		Id:    req.GetId(),
		Name:  "張三",
		Email: "zhangsan@example.com",
	}
	return &pb.GetUserResponse{User: user}, nil
}
// CreateUser實現(xiàn)
func (s *userService) CreateUser(ctx context.Context, req *pb.CreateUserRequest) (*pb.CreateUserResponse, error) {
	// 模擬創(chuàng)建用戶
	user := &pb.User{
		Id:    1,
		Name:  req.GetName(),
		Email: req.GetEmail(),
	}
	return &pb.CreateUserResponse{User: user}, nil
}
// ListUsers實現(xiàn)（流式）
func (s *userService) ListUsers(req *pb.ListUsersRequest, stream pb.UserService_ListUsersServer) error {
	// 模擬批量獲取用戶
	users := []*pb.User{
		{Id: 1, Name: "張三", Email: "zhangsan@example.com"},
		{Id: 2, Name: "李四", Email: "lisi@example.com"},
		{Id: 3, Name: "王五", Email: "wangwu@example.com"},
	}
	for _, user := range users {
		if err := stream.Send(&pb.ListUsersResponse{User: user}); err != nil {
			return err
		}
	}
	return nil
}
func main() {
	// 創(chuàng)建gRPC服務(wù)器
	server := grpc.NewServer()
	// 注冊服務(wù)
	pb.RegisterUserServiceServer(server, &userService{})
	// 監(jiān)聽端口
	listener, err := net.Listen("tcp", ":50051")
	if err != nil {
		log.Fatalf("Failed to listen: %v", err)
	}
	fmt.Println("Server is running on port 50051")
	if err := server.Serve(listener); err != nil {
		log.Fatalf("Failed to serve: %v", err)
	}
}

package main
import (
	"context"
	"fmt"
	"log"
	"google.golang.org/grpc"
	pb "your-project/user"
)
func main() {
	// 連接服務(wù)器
	conn, err := grpc.Dial("localhost:50051", grpc.WithInsecure())
	if err != nil {
		log.Fatalf("Failed to connect: %v", err)
	}
	defer conn.Close()
	// 創(chuàng)建客戶端
	client := pb.NewUserServiceClient(conn)
	// 測試GetUser
	getUserReq := &pb.GetUserRequest{Id: 1}
	getUserResp, err := client.GetUser(context.Background(), getUserReq)
	if err != nil {
		log.Fatalf("Failed to get user: %v", err)
	}
	fmt.Printf("GetUser response: %v\n", getUserResp)
	// 測試CreateUser
	createUserReq := &pb.CreateUserRequest{
		Name:  "趙六",
		Email: "zhaoliu@example.com",
	}
	createUserResp, err := client.CreateUser(context.Background(), createUserReq)
	if err != nil {
		log.Fatalf("Failed to create user: %v", err)
	}
	fmt.Printf("CreateUser response: %v\n", createUserResp)
	// 測試ListUsers（流式）
	listUsersReq := &pb.ListUsersRequest{
		Page:     1,
		PageSize: 10,
	}
	stream, err := client.ListUsers(context.Background(), listUsersReq)
	if err != nil {
		log.Fatalf("Failed to list users: %v", err)
	}
	for {
		resp, err := stream.Recv()
		if err != nil {
			break
		}
		fmt.Printf("ListUsers response: %v\n", resp)
	}
}

// 服務(wù)端攔截器
func loggingInterceptor(ctx context.Context, req interface{}, info *grpc.UnaryServerInfo, handler grpc.UnaryHandler) (interface{}, error) {
	log.Printf("Received request: %v", info.FullMethod)
	resp, err := handler(ctx, req)
	log.Printf("Sent response: %v", info.FullMethod)
	return resp, err
}
// 注冊攔截器
server := grpc.NewServer(
	grpc.UnaryInterceptor(loggingInterceptor),
)

// 客戶端設(shè)置超時
ctx, cancel := context.WithTimeout(context.Background(), 5*time.Second)
defer cancel()
resp, err := client.GetUser(ctx, req)

// 服務(wù)端返回錯誤
func (s *userService) GetUser(ctx context.Context, req *pb.GetUserRequest) (*pb.GetUserResponse, error) {
	if req.GetId() <= 0 {
		return nil, status.Errorf(codes.InvalidArgument, "Invalid user ID")
	}
	// 其他邏輯...
}
// 客戶端處理錯誤
resp, err := client.GetUser(ctx, req)
if err != nil {
	if status, ok := status.FromError(err); ok {
		switch status.Code() {
		case codes.InvalidArgument:
			fmt.Println("Invalid argument error")
		case codes.NotFound:
			fmt.Println("User not found")
		default:
			fmt.Println("Unknown error")
		}
	}
}