Go Web编程 Chapter3

Go web编程

Chapter_3 Handling_Requests

chain_handler

package main

import (
	"fmt"
	"net/http"
)

type HelloHandler struct{}

func (h HelloHandler) ServeHTTP(w http.ResponseWriter, r *http.Request) {
	fmt.Fprintf(w, "Hello!")
}

func log(h http.Handler) http.Handler {
	return http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
		fmt.Printf("Handler called - %T\n", h)
		h.ServeHTTP(w, r)
	})
}

func protect(h http.Handler) http.Handler {
	return http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
		// some code to make sure the user is authorized
		h.ServeHTTP(w, r)
	})
}

func main() {
	server := http.Server{
		Addr: "127.0.0.1:8080",
	}
	hello := HelloHandler{}
	http.Handle("/hello", protect(log(hello)))
	server.ListenAndServe()
}

chain_handlerfunc

package main

import (
	"fmt"
	"net/http"
	"reflect"
	"runtime"
)

func hello(w http.ResponseWriter, r *http.Request) {
	fmt.Fprintf(w, "Hello!")
}

func log(h http.HandlerFunc) http.HandlerFunc {
	return func(w http.ResponseWriter, r *http.Request) {
		name := runtime.FuncForPC(reflect.ValueOf(h).Pointer()).Name()
		fmt.Println("Handler function called - " + name)
		h(w, r)
	}
}

func main() {
	server := http.Server{
		Addr: "127.0.0.1:8080",
	}
	http.HandleFunc("/hello", log(hello))
	server.ListenAndServe()
}

configurable

package main

import (
	"net/http"
)

func main() {
	server := http.Server{
		Addr:    "127.0.0.1:8080",
		Handler: nil,
	}
	server.ListenAndServe()
}

gencert

package main

import (
	"crypto/rand"
	"crypto/rsa"
	"crypto/x509"
	"crypto/x509/pkix"
	"encoding/pem"
	"math/big"
	"net"
	"os"
	"time"
)

func main() {
	max := new(big.Int).Lsh(big.NewInt(1), 128)
	serialNumber, _ := rand.Int(rand.Reader, max)
	subject := pkix.Name{
		Organization:       []string{"Manning Publications Co."},
		OrganizationalUnit: []string{"Books"},
		CommonName:         "Go Web Programming",
	}

	template := x509.Certificate{
		SerialNumber: serialNumber,
		Subject:      subject,
		NotBefore:    time.Now(),
		NotAfter:     time.Now().Add(365 * 24 * time.Hour),
		KeyUsage:     x509.KeyUsageKeyEncipherment | x509.KeyUsageDigitalSignature,
		ExtKeyUsage:  []x509.ExtKeyUsage{x509.ExtKeyUsageServerAuth},
		IPAddresses:  []net.IP{net.ParseIP("127.0.0.1")},
	}

	pk, _ := rsa.GenerateKey(rand.Reader, 2048)

	derBytes, _ := x509.CreateCertificate(rand.Reader, &template, &template, &pk.PublicKey, pk)
	certOut, _ := os.Create("cert.pem")
	pem.Encode(certOut, &pem.Block{Type: "CERTIFICATE", Bytes: derBytes})
	certOut.Close()

	keyOut, _ := os.Create("key.pem")
	pem.Encode(keyOut, &pem.Block{Type: "RSA PRIVATE KEY", Bytes: x509.MarshalPKCS1PrivateKey(pk)})
	keyOut.Close()
}

handler

package main

import (
	"fmt"
	"net/http"
)

type MyHandler struct{}

func (h *MyHandler) ServeHTTP(w http.ResponseWriter, r *http.Request) {
	fmt.Fprintf(w, "Hello World!")
}

func main() {
	handler := MyHandler{}
	server := http.Server{
		Addr:    "127.0.0.1:8080",
		Handler: &handler,
	}
	server.ListenAndServe()
}

handlerfunc

package main

import (
	"fmt"
	"net/http"
)

func hello(w http.ResponseWriter, r *http.Request) {
	fmt.Fprintf(w, "Hello!")
}

func world(w http.ResponseWriter, r *http.Request) {
	fmt.Fprintf(w, "World!")
}

func main() {
	server := http.Server{
		Addr: "127.0.0.1:8080",
	}
	http.HandleFunc("/hello", hello)
	http.HandleFunc("/world", world)

	server.ListenAndServe()
}

httprouter

package main

import (
   "fmt"
   "github.com/julienschmidt/httprouter"
   "net/http"
)

func hello(w http.ResponseWriter, r *http.Request, p httprouter.Params) {
   fmt.Fprintf(w, "hello, %s!\n", p.ByName("name"))
}

func main() {
   mux := httprouter.New()
   mux.GET("/hello/:name", hello)

   server := http.Server{
      Addr:    "127.0.0.1:8080",
      Handler: mux,
   }
   server.ListenAndServe()
}

https

package main

import (
   "net/http"
)

func main() {
   server := http.Server{
      Addr:    "127.0.0.1:8080",
      Handler: nil,
   }
   server.ListenAndServeTLS("cert.pem", "key.pem")
}

multihandler

package main

import (
   "fmt"
   "net/http"
)

type HelloHandler struct{}

func (h *HelloHandler) ServeHTTP(w http.ResponseWriter, r *http.Request) {
   fmt.Fprintf(w, "Hello!")
}

type WorldHandler struct{}

func (h *WorldHandler) ServeHTTP(w http.ResponseWriter, r *http.Request) {
   fmt.Fprintf(w, "World!")
}

func main() {
   hello := HelloHandler{}
   world := WorldHandler{}

   server := http.Server{
      Addr: "127.0.0.1:8080",
   }

   http.Handle("/hello", &hello)
   http.Handle("/world", &world)

   server.ListenAndServe()
}

simplest

package main

import (
   "net/http"
)

func main() {
   http.ListenAndServe("", nil)
}