go语言拦截器的简单实现
拦截器服务端
interceptor := func(ctx context.Context, req interface{}, info *grpc.UnaryServerInfo, handler grpc.UnaryHandler) (resp interface{}, err error) { start := time.Now() fmt.Println("收到请求") c, r := handler(ctx, req) fmt.Printf("执行时间:%s\n", time.Since(start)) return c, r } opt := grpc.UnaryInterceptor(interceptor) // 实例化grpc Server s := grpc.NewServer(opt)
package main import ( "fmt" "google.golang.org/grpc/metadata" "net" "time" "golang.org/x/net/context" "google.golang.org/grpc" "google.golang.org/grpc/grpclog" pb "rpc/hello_proto/proto" // 引入编译生成的包 ) const ( // Address gRPC服务地址 Address = "127.0.0.1:12345" ) // 定义helloService并实现约定的接口 type helloService struct{} // HelloService Hello服务 var HelloService = helloService{} // SayHello 实现Hello服务接口 func (h helloService) SayHello(ctx context.Context, in *pb.HelloRequest) (*pb.HelloResponse, error) { //服务端 获取metadata md, ok := metadata.FromIncomingContext(ctx) if !ok { fmt.Println("metadata get err") } else { if name, ok := md["name"]; ok { fmt.Println(name[0]) } } resp := new(pb.HelloResponse) resp.Message = fmt.Sprintf("Hello %s.", in.Name) return resp, nil } func main() { listen, err := net.Listen("tcp", Address) if err != nil { grpclog.Fatalf("Failed to listen: %v", err) } interceptor := func(ctx context.Context, req interface{}, info *grpc.UnaryServerInfo, handler grpc.UnaryHandler) (resp interface{}, err error) { start := time.Now() fmt.Println("收到请求") c, r := handler(ctx, req) fmt.Printf("执行时间:%s\n", time.Since(start)) return c, r } opt := grpc.UnaryInterceptor(interceptor) // 实例化grpc Server s := grpc.NewServer(opt) // 注册HelloService pb.RegisterHelloServer(s, HelloService) grpclog.Println("Listen on " + Address) s.Serve(listen) }
拦截器客户端
opt := grpc.WithUnaryInterceptor(func(ctx context.Context, method string, req, reply interface{}, cc *grpc.ClientConn, invoker grpc.UnaryInvoker, opts ...grpc.CallOption) error { start := time.Now() err := invoker(ctx, method, req, reply, cc) fmt.Printf("请求花费时间:%s\n", time.Since(start)) return err }) // 连接 conn, err := grpc.Dial(Address, grpc.WithInsecure(), opt)
package main import ( "fmt" "golang.org/x/net/context" "google.golang.org/grpc" "google.golang.org/grpc/metadata" pb "rpc/hello_proto/proto" // 引入编译生成的包 "time" ) const ( // Address gRPC服务地址 Address = "127.0.0.1:12345" ) func main() { opt := grpc.WithUnaryInterceptor(func(ctx context.Context, method string, req, reply interface{}, cc *grpc.ClientConn, invoker grpc.UnaryInvoker, opts ...grpc.CallOption) error { start := time.Now() err := invoker(ctx, method, req, reply, cc) fmt.Printf("请求花费时间:%s\n", time.Since(start)) return err }) // 连接 conn, err := grpc.Dial(Address, grpc.WithInsecure(), opt) if err != nil { fmt.Println(err) } defer conn.Close() // 初始化客户端 c := pb.NewHelloClient(conn) //客户端 写入metadata //md := metadata.Pairs("name", "张三", "pwd", "123456") //或 md := metadata.New( map[string]string{ "name": "张三", "pwd": "123456", }) ctx := metadata.NewOutgoingContext(context.Background(), md) // 调用方法 req := &pb.HelloRequest{Name: "gRPC"} res, err := c.SayHello(ctx, req) if err != nil { fmt.Println(err) } fmt.Println(res.Message) }
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