1.proto

syntax = "proto3";
option go_package = ".;proto";
service Greeter {
  rpc SayHello (HelloRequest) returns (HelloReply);
}
//将session放入 放入cookie中 http协议
message HelloRequest {
  string name = 1;
}
message HelloReply {
  string message = 1;
}

2.server

package main
import (
    "OldPackageTest/grpc_interceptor/proto"
    "context"
    "fmt"
    "google.golang.org/grpc"
    "net"
)
type Server struct {
}
func (s *Server) SayHello(ctx context.Context, request *proto.HelloRequest) (*proto.HelloReply, error) {
    return &proto.HelloReply{
        Message: "hello " + request.Name,
    }, nil
}
func main() {
    var interceptor grpc.UnaryServerInterceptor
    interceptor = func(ctx context.Context, req interface{}, info *grpc.UnaryServerInfo, handler grpc.UnaryHandler) (resp interface{}, err error) {
        //继续处理请求
        fmt.Println("接收到新请求")
        res, err := handler(ctx, req)
        fmt.Println("请求处理完成")
        return res, err
    }
    var opts []grpc.ServerOption
    opts = append(opts, grpc.UnaryInterceptor(interceptor))
    g := grpc.NewServer(opts...)
    proto.RegisterGreeterServer(g, &Server{})
    lis, err := net.Listen("tcp", "0.0.0.0:50051")
    if err != nil {
        panic("failed to listen" + err.Error())
    }
    err = g.Serve(lis)
    if err != nil {
        panic("failed to start" + err.Error())
    }
}

package main
import (
    "OldPackageTest/grpc_test/proto"
    "context"
    "fmt"
    "google.golang.org/grpc"
    "net"
)
type Server struct {
}
func (s *Server) SayHello(ctx context.Context, request *proto.HelloRequest) (*proto.HelloReply, error) {
    return &proto.HelloReply{
        Message: "hello " + request.Name,
    }, nil
}
func main() {
    interceptor := func(ctx context.Context, req interface{}, info *grpc.UnaryServerInfo, handler grpc.UnaryHandler) (resp interface{}, err error) {
        fmt.Println("接收到了一个新的请求")
        res,err := handler(ctx, req)
        fmt.Println("请求已经完成")
        return res,err
    }
    opt := grpc.UnaryInterceptor(interceptor)
    g := grpc.NewServer(opt)
    proto.RegisterGreeterServer(g, &Server{})
    lis, err := net.Listen("tcp", "0.0.0.0:8080")
    if err != nil {
        panic("failed to listen" + err.Error())
    }
    err = g.Serve(lis)
    if err != nil {
        panic("failed to start" + err.Error())
    }
}

3.client

package main
import (
    "OldPackageTest/grpc_interceptor/proto"
    "context"
    "fmt"
    "google.golang.org/grpc"
    "time"
)
func interceptor(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, opts...)
    if err != nil {
        return err
    }
    fmt.Printf("耗时: %s\n",time.Since(start))
    return err
}
func main() {
    //stream
    var opts []grpc.DialOption
    opts = append(opts,grpc.WithInsecure())
    //指定客户端 interceptor
    opts = append(opts,grpc.WithUnaryInterceptor(interceptor))
    conn,err := grpc.Dial("localhost:50051",opts...)
    if err != nil{
        panic(err)
    }
    defer conn.Close()
    c := proto.NewGreeterClient(conn)
    r, err := c.SayHello(context.Background(), &proto.HelloRequest{Name: "Anwma"})
    if err != nil {
        panic(err)
    }
    fmt.Println(r.Message)
}

package main
import (
    "OldPackageTest/grpc_test/proto"
    "context"
    "fmt"
    "google.golang.org/grpc"
    "time"
)
func main() {
    //stream
    interceptor := 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, opts...)
        if err != nil {
            return err
        }
        fmt.Printf("耗时: %s\n",time.Since(start))
        return err
    }
    var opts []grpc.DialOption
    opts = append(opts,grpc.WithInsecure())
    opts = append(opts,grpc.WithUnaryInterceptor(interceptor))
    //opt := grpc.WithUnaryInterceptor(interceptor)
    //conn, err := grpc.Dial("127.0.0.1:8080", grpc.WithInsecure(),opt)
    conn, err := grpc.Dial("127.0.0.1:8080", opts...)
    if err != nil {
        panic(err)
    }
    defer conn.Close()
    c := proto.NewGreeterClient(conn)
    r, err := c.SayHello(context.Background(), &proto.HelloRequest{Name: "Anwma"})
    if err != nil {
        panic(err)
    }
    fmt.Println(r.Message)
}

4. 拦截器的应用场景