Golang get and POST request sending and parsing for Web programming

This article is an introductory article that introduces the techniques used by Golang Web programming through a simple example.

The structure of the article includes:

1. Client-get Request
   
2. Client-post Request
   
3. Server processes Get and Post data

In the encapsulation of data, we use JSON in part, so this article also involves the encoding and decoding of JSON in Golang.

First, Client-get

Package Mainimport (        "FMT"        "Net/url" "Net/http" "        io/ioutil" "        Log") func main () {        U, _: = URL. Parse ("Http://localhost:9001/xiaoyue")        Q: = U.query ()        q.set ("username", "user")        q.set ("Password", " passwd ")        u.rawquery = Q.encode ()        res, err: = http. Get (U.string ());       If err! = Nil {               log. Fatal (ERR) return         }       result, err: = Ioutil. ReadAll (Res. Body)         Res. Body.close ()         if err! = Nil {               log. Fatal (ERR) return         }         fmt. Printf ("%s", result)}

Second, Client-post

Package Mainimport ("FMT" "Net/url" "Net/http" "Io/ioutil" "Log" "bytes" "Encoding/json") type Server struct {ServerName string ServerIP string}type serverslice struct {S        ervers []server serversid string}func Main () {var s serverslice  var NewServer Server;        Newserver.servername = "Guangzhou_vpn"; Newserver.serverip = "127.0.0.1" s.servers = Append (S.servers, newserver)   s.servers = append (s.s  Ervers, Server{servername: "Shanghai_vpn", ServerIP: "127.0.0.2"}) s.servers = Append (S.servers, Server{servername: "Beijing_vpn", ServerIP: "127.0.0.3"})                  s.serversid = "team1"         B, err: = json. Marshal (s)         if err! = Nil {                 FMT. PRINTLN ("JSON err:", err)        }        Body: = bytes. Newbuffer ([]byte (b))         Res,err: = http. Post ("Http://localhost:9001/xiaoyue", "Application/json;charset=utf-8", body)          If Err! = Nil {                 Log. Fatal (ERR)                 return        }        result, err: = Ioutil. ReadAll (Res. Body)         Res. Body.close ()         if err! = Nil {                 log. Fatal (ERR)               &NBSp return       }        FMT. Printf ("%s", result)}

Third, the Server

Package Mainimport ("FMT" "Net/http" "Strings" "html" "Io/ioutil" "Encoding/jso n ") type Server struct {ServerName string ServerIP string}type serverslice struct {Servers []serve R serversid String}func Main () {  HTTP. Handlefunc ("/", handler) HTTP. Listenandserve (": 9001", nil)}func Handler (w http. Responsewriter, R *http. Request) {r.parseform ()//parse parameter, default is FMT not resolved. fprintf (W, "Hi, I Love you%s", HTML. Escapestring (R.url. Path[1:]))  if R.method = = "GET" { fmt. Println ("Method:", R.method)//Get the method requested by FMT. Println ("username", r.form["username"]) fmt. PRINTLN ("Password", r.form["password"]) for k, V: = Range R.form { fmt.                       Print ("Key:", K, ";")  fmt. Println ("Val:", Strings. Join (V, ""))  }} else if R.method = = "POST" {&nbsp result, _:= Ioutil. ReadAll (R.body)  r.body.close ()  fmt. The recommended handling method for Printf ("%s\n", result)//unknown type  var f interface{}  json.                       Unmarshal (result, &f) m: = f. (map[string]interface{})  for K, V: = range m {                                        switch VV: = V. (type) { case string:  fmt. Println (k, "is string", vv)  case int:  fmt. Println (k, "is int", VV)  case float64:  fmt . Println (K, "is Float64", vv)  case []interface{}: & Nbsp;fmt.                                               Println (K, "is an array:")  for i, U: = Range VV { &nbsP;fmt.                                       Println (i, U)  }  default:  fmt. Println (K, "is of a type I don ' t know how to Handle")}  } /struct known, resolves to struct  var s serverslice;     json. Unmarshal ([]byte (Result), &s)           FMT. Println (S.SERVERSID);           for i:=0; I<len (s.servers); i++ {                FMT. Println (S.servers[i]. ServerName)                   FMT . Println (S.servers[i]. ServerIP)         } }}