接收消息

更多Go内容请见： https://blog.youkuaiyun.com/weixin_39777626/article/details/85066750

net/http标准库

组成部分

构建服务器

Go Web服务器
最简单的Web服务器

package main

import (
	"net/http"
)

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

附加配置的Web服务器

package main

import (
	"net/http"
)

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

HTTPS提供服务

• cert.pem：SSL证书
• key.pem：私钥
• SSL：（Secure Socket
  Layer，安全套接字层）通过公钥基础设施为通信双方提供数据加密和身份验证的协议，后更名为TLS（Transport Layer
  Security，传输层安全协议）
• HTTPS：在SSL之连接上层进行HTTP通信

通过HTTPS提供服务

package main

import (
	"net/http"
)

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

生成个人使用的SSL证书以及服务器私钥

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,	//证书序列号
		Subject:		subject,				//证书标题
		//证书有效期：一年
		NotBefore:		time.Now(),
		NotAfter:		time.Now().Add(365*24*time.Hour),
		KeyUsage:		x509.KeyUsageKeyEncipherment|x509.KeyUsageDigitalSignature,
		ExtKeyUsage:	[]x509.ExtKeyUsage{x509.ExtKeyUsageServerAuth},	//X.509证书用于服务器验证操作
		IPAddresses:	[]net.IP{net.ParseIP("127.0.0.1")},						//证书只能在127.0.0.1上运行
	}
	
	//生成RSA私钥
	pk,_:=rsa.GenerateKey(rand.Reader,2048)
	
	//创建出经过DER编码格式化的字节切片
	derBytes,_:=x509.CreateCertificate(rand.Reader,&template,&template,&pk.PublicKey,pk)
	
	//将证书编码到cert.pem文件里
	certOut,_:=os.Create("cert.pem")
	pem.Encode(certOut,&pem.Block{Type:"CERTIFICATE",Bytes:derBytes})
	certOut.Close()
	
	//将密钥编码并保存到key.pem文件里
	keyOut,_:=os.Create("key.pem")
	pem.Encode(keyOut,&pem.Block{Type:"RSA PIRVATE KEY",Bytes:x509.MarshalPKCS1PrivateKey(pk)})
	keyOut.Close()
}

处理器和处理函数

处理请求
DefaulltServeMux

package main

import (
	"fmt"
	"net/http"
)

type MyHandleer struct{}

func (h *MyHandleer) ServeHTTP(w http.ResponseWriter, r *http.Request) {
	fmt.Fprintf(w, "Hello World!")
}
func main() {
	handler := MyHandleer{}
	server := http.Server{
		Addr:    "127.0.0.1:8080",
		Handler: &handler,
	}
	server.ListenAndServe()
}

使用多个处理器

package main

import (
	"fmt"
	"net/http"
)

type HelloHandleer struct{}

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

type WorldHandleer struct{}

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

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

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

	server.ListenAndServe()
}

处理器函数

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()
}

串联多个处理器和处理器函数

串联两个二处理器函数

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()
}

串联多个处理器

package main

import (
	"fmt"
	"net/http"
)

type HelloHandleer struct{}

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

func log(h http.HandlerFunc) http.HandlerFunc {
	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){
		h.ServeHTTP (w,r)
	})
}

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

ServeMux和DefaultServeMux

	ServeMux	DefaultServeMux
实质	HTTP请求多路复用器	ServeMux的一个实例
功能	接收HTTP请求并根据请求中的URL将请求重定向到正确的处理器	引入net/http标准库的程序都可以使用这个实例

使用其他多路复用器

注意：编译前，先安装git，然后在终端执行以下命令，以安装HttpRouter库

go get github.com/julienschmidt/httprouter

使用HttpRouter实现的服务器

package main

import (
	"fmt"
	"net/http"

	"github.com/julienschmidt/httprouter"
)

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()
}

更多Go内容请见： https://blog.youkuaiyun.com/weixin_39777626/article/details/85066750