如何在Go中編寫簡單的自定義http服務器？

Question

我是新手，試圖編寫自定義http server.Getting編譯錯誤。我如何在我的代碼中實現ServeHTTP方法？

我的代碼：

package main 

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


func myHandler(w http.ResponseWriter, req *http.Request){ 
    io.WriteString(w, "hello, world!\n") 
} 


func main() { 

    //Custom http server 
    s := &http.Server{ 
     Addr:   ":8080", 
     Handler:  myHandler, 
     ReadTimeout: 10 * time.Second, 
     WriteTimeout: 10 * time.Second, 
     MaxHeaderBytes: 1 << 20, 
    } 

    err := s.ListenAndServe() 
    if err != nil { 
     fmt.Printf("Server failed: ", err.Error()) 
    } 
} 

錯誤而編譯：

.\hello.go:21: cannot use myHandler (type func(http.ResponseWriter, *http.Request)) as type http.Handler in field value: 
    func(http.ResponseWriter, *http.Request) does not implement http.Handler (missing ServeHTTP method) 

Answer 1

你要麼使用結構，並在其上定義ServeHTTP或者乾脆換你的函數在HandlerFunc

s := &http.Server{ 
    Addr:   ":8080", 
    Handler:  http.HandlerFunc(myHandler), 
    ReadTimeout: 10 * time.Second, 
    WriteTimeout: 10 * time.Second, 
    MaxHeaderBytes: 1 << 20, 
} 

Answer 2

爲了正常工作，myHandler應該是一個滿足Handler Interface的對象，換句話說myHandler應該有稱爲ServeHTTP的方法。

例如，假設myHandler是用於顯示當前時間的自定義處理程序。代碼應該是這樣的

package main 

import (
    "fmt" 
    "net/http" 
    "time" 
) 

type timeHandler struct { 
    zone *time.Location 
} 

func (th *timeHandler) ServeHTTP(w http.ResponseWriter, r *http.Request) { 
    tm := time.Now().In(th.zone).Format(time.RFC1123) 
    w.Write([]byte("The time is: " + tm)) 
} 

func newTimeHandler(name string) *timeHandler { 
    return &timeHandler{zone: time.FixedZone(name, 0)} 
} 

func main() { 

    myHandler := newTimeHandler("EST") 
    //Custom http server 
    s := &http.Server{ 
     Addr:   ":8080", 
     Handler:  myHandler, 
     ReadTimeout: 10 * time.Second, 
     WriteTimeout: 10 * time.Second, 
     MaxHeaderBytes: 1 << 20, 
    } 

    err := s.ListenAndServe() 
    if err != nil { 
     fmt.Printf("Server failed: ", err.Error()) 
    } 
} 

運行此代碼並在您的瀏覽器中訪問​​。你應該看到類似這樣的

The time is: Sat, 30 Aug 2014 18:19:46 EST 

（你應該看到不同的時間。）

希望這有助於格式化文本，

進一步閱讀

A Recap of Request Handling in Go

Answer 3

結果： tonycai @ frog：〜$ curl「http://localhost:4000」 現在時間是：2018年1月12日星期五04:11:18 EST

但是，如何更改時區？從EST到CST