[云原生] Go web工作流程

web工作流程

• Web服务器的工作原理可以简单地归纳为
  • 客户机通过TCP/IP协议建立到服务器的TCP连接
  • 客户端向服务器发送HTTP协议请求包，请求服务器里的资源文档
  • 服务器向客户机发送HTTP协议应答包，如果请求的资源包含有动态语言的内容，那么服务器会调用动态语言的解释引擎负责处理“动态内容”，并将处理得到的数据返回给客户端
  • 客户机与服务器断开。由客户端解释HTML文档，在客户端屏幕上渲染图形结果

HTTP协议

• 超文本传输协议(HTTP，HyperText Transfer Protocol)是互联网上应用最为广泛的一种网络协议，它详细规定了浏览器和万维网服务器之间互相通信的规则，通过因特网传送万维网文档的数据传送协议

• HTTP协议通常承载于TCP协议之上

  talk is cheap , show me the code

package mainimport ("fmt""io/ioutil""log""net/http"
)func main() {//http://127.0.0.1:8000/go// 单独写回调函数http.HandleFunc("/go", myHandler)// addr：监听的地址// handler：回调函数http.ListenAndServe("127.0.0.1:8000", nil)
}// handler函数
func myHandler(w http.ResponseWriter, r *http.Request) {fmt.Println(r.RemoteAddr, "连接成功")// 请求方式：GET POST DELETE PUT UPDATEfmt.Println("method:", r.Method)// /gofmt.Println("url:", r.URL.Path)fmt.Println("header:", r.Header)fmt.Println("body:", r.Body)// 回复switch r.Method {case "GET":{w.Write([]byte("get"))}case "POST":{// 读取body内容content, err := ioutil.ReadAll(r.Body)if err != nil {log.Println("read post body occurs error: ", err)}fmt.Println("post body:", string(content))w.Write([]byte("post"))}default:{w.Write([]byte(r.Method))}}fmt.Println("end---")
}

package mainimport ("encoding/json""fmt""io""log""net/http""strings"
)type Data struct {Name string `json:"name"`Age  int8   `json:"age"`
}func main() {//resp, _ := http.Get("http://www.baidu.com")//fmt.Println(resp)resp, _ := http.Get("http://127.0.0.1:8000/go")ResponseHandler(resp)fmt.Println("----")data := &Data{Name: "hello",Age:  18,}// 转换成json格式data_json, err := json.Marshal(data)if err != nil {log.Println("json.Marshaler error: ", err)}fmt.Println(string(data_json))resp, _ = http.Post("http://127.0.0.1:8000/go", "application/json", strings.NewReader(string(data_json)))ResponseHandler(resp)
}func ResponseHandler(resp *http.Response) {defer resp.Body.Close()// 200 OKfmt.Println(resp.Status)fmt.Println(resp.Header)buf := make([]byte, 1024)for {// 接收服务端信息n, err := resp.Body.Read(buf)if err != nil && err != io.EOF {fmt.Println(err)return} else {fmt.Println("读取完毕")res := string(buf[:n])fmt.Println(res)break}}
}

结果

> go run .\server.go
127.0.0.1:54856 连接成功
method: GET
url: /go
header: map[Accept-Encoding:[gzip] User-Agent:[Go-http-client/1.1]]
body: {}
end---
127.0.0.1:54856 连接成功
method: POST
url: /go
header: map[Accept-Encoding:[gzip] Content-Length:[25] Content-Type:[application/json] User-Agent:[Go-http-client/1.1]]
body: &{0xc0000b6048 <nil> <nil> false true {0 0} false false false 0x475080}
post body: {"name":"hello","age":18}
end---

> go run .\client.go
200 OK
map[Content-Length:[3] Content-Type:[text/plain; charset=utf-8] Date:[Mon, 25 Apr 2022 17:17:31 GMT]]
读取完毕
get
----
{"name":"hello","age":18}
200 OK
map[Content-Length:[4] Content-Type:[text/plain; charset=utf-8] Date:[Mon, 25 Apr 2022 17:17:31 GMT]]
读取完毕
post

http handler的格式模板

// HandleFunc registers the handler function for the given pattern
// in the DefaultServeMux.
// The documentation for ServeMux explains how patterns are matched.
func HandleFunc(pattern string, handler func(ResponseWriter, *Request)) {DefaultServeMux.HandleFunc(pattern, handler)
}