go http 分析

原生http

http.ListenAndServe

handler 參數(w http.ResponseWriter, r *http.Request)

go參數傳遞爲值傳遞，request長用來獲取參數等，因此直接傳遞指針比較好，而 ResponseWriter 是個接口，只要實現接口就行 無所謂傳不傳指針的問題。

package main

import (
	"net/http"
	"log"
	"io"
)

func main() {

	http.Handle("/", sayHello)

	err := http.ListenAndServe(":8080", nil)
	if err != nil {
		log.Fatal(err)
	}
}

func sayHello(w http.ResponseWriter, r *http.Request)  {
	io.WriteString(w, "hello world, version 1")
}



//訪問 http://localhost:8080/

http.ServeMux 更底層路由設置

http.ServeMux解析

ServeMux 實際上是路由表，主要使用map結構，其實例必須實現 ServeHTTP() 方法

mux.m[pattern] = muxEntry{explicit: true, h: handler, pattern: pattern}

package main

import (
	"net/http"
	"io"
	"log"
)

func main() {

	mux := http.NewServeMux() //路由表結構
	mux.Handle("/", &MyHandler{}) //這裏註冊的是處理的指針,默認根路徑"/"
	mux.HandleFunc("/hello", sayHello) //註冊/hello 

	err := http.ListenAndServe(":8080", mux) // 將mux 放入
	if err != nil {
		log.Fatal(err)
	}
}


type MyHandler struct {
	
}

func (_ * MyHandler) ServeHTTP(w http.ResponseWriter, r *http.Request)  {
	io.WriteString(w, "URL: " + r.URL.String() )
}

func sayHello(w http.ResponseWriter, r *http.Request)  {
	io.WriteString(w, "hello world, version 2")
}


//訪問 http://localhost:8080/
//訪問 http://localhost:8080/hello

更進一步實現http.Server

本身實現Server 最重要的是須要本身在 ServeHTTP() 中實現路由轉發

package main

import (
	"net/http"
	"io"
	"log"
	"time"
)

var mux map[string]func(w http.ResponseWriter, r *http.Request)

func main() {

	server := http.Server{
		Addr : ":8080", //設置地址
		Handler : &MyHandler{}, //設置處理handler
		ReadTimeout : 5 * time.Second, //設置超時時間 5S
	}

	//由於沒有提供方法，因此須要本身實現路由，而後在ServeHTTP中進行路由轉發
	mux = make(map[string]func(w http.ResponseWriter, r *http.Request))
	mux["/hello"] = sayHello
	mux["/bye"] = sayBye

	err := server.ListenAndServe() // 使用本身實例化的server
	if err != nil {
		log.Fatal(err)
	}
}

type MyHandler struct {

}

func (_ *MyHandler) ServeHTTP(w http.ResponseWriter, r *http.Request) {
	//由於這裏沒有方法，因此須要進行路由轉發
	if h, ok := mux[r.URL.String()]; ok {
		h(w, r) //若是存在就轉發
		return
	}
	io.WriteString(w, "URL: " + r.URL.String())
}

func sayHello(w http.ResponseWriter, r *http.Request) {
	io.WriteString(w, "hello world, version 3")
}

func sayBye(w http.ResponseWriter, r *http.Request) {
	io.WriteString(w, "bye bye, version 3")
}


//訪問 http://localhost:8080/
//訪問 http://localhost:8080/hello
//訪問 http://localhost:8080/bye

靜態文件

靜態文件就須要使用到http.FileServer

使用Golang 搭建http web服務器

package main

import (
	"net/http"
	"io"
	"log"
	"os"
)

func main() {

	mux := http.NewServeMux()
	mux.Handle("/", &MyHandler{})
	mux.HandleFunc("/hello", sayHello)

	wd, err := os.Getwd()// 獲取當前路徑
	if err != nil {
		log.Fatal(err)
	}

	//http.Dir(wd) //獲取相對路徑
	//http.FileServer 靜態處理
	mux.Handle("/static/", http.StripPrefix("/static/", http.FileServer(http.Dir(wd)))) //設置靜態文件路徑

	err = http.ListenAndServe(":8080", mux)
	if err != nil {
		log.Fatal(err)
	}
}


type MyHandler struct {

}

func (_ * MyHandler) ServeHTTP(w http.ResponseWriter, r *http.Request)  {
	io.WriteString(w, "URL: " + r.URL.String() )
}

func sayHello(w http.ResponseWriter, r *http.Request)  {
	io.WriteString(w, "hello world, version 4")
}



// http://localhost:8080/static/