Golang WebプログラミングのGetとPostリクエストの送信と解析

本稿では,GolangのWebプログラミングで主に用いられる技術を簡単な例で紹介する入門記事である.
          記事の構造は次のとおりです.

Client-Getリクエスト

Client-Post 要求

Server処理GetおよびPostデータ

          データのパッケージでは,部分的にjsonを採用しているので,Golangにおけるjsonの符号化と復号化にも関与する.
一、Client-Get

package main

import (
        "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)
} 

 
   
  
二、Client-Post
 
   
   
  
package main

import (
        "fmt"
        "net/url"
        "net/http"
        "io/ioutil"
        "log"
        "bytes"
        "encoding/json"
)

type Server struct {
        ServerName string
        ServerIP   string
}

type Serverslice struct {
        Servers []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.Servers, 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)
                return
        }
        fmt.Printf("%s", result)
}
  
三、Server
package main

import (
        "fmt"
        "net/http"
        "strings"
        "html"
        "io/ioutil"
        "encoding/json"
)

type Server struct {
        ServerName string
        ServerIP   string
}

type Serverslice struct {
        Servers []Server
        ServersID  string
}

func main() {
        http.HandleFunc("/", handler) 
        http.ListenAndServe(":9001", nil)
}

func handler(w http.ResponseWriter, r *http.Request) { 
        r.ParseForm() //    ，         
        fmt.Fprintf(w, "Hi, I love you %s", html.EscapeString(r.URL.Path[1:]))
        if r.Method == "GET" {
                fmt.Println("method:", r.Method) //        

                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" {
                result, _:= ioutil.ReadAll(r.Body)
                r.Body.Close()
                fmt.Printf("%s
", result)

                //           

                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{}:
                                        fmt.Println(k, "is an array:")
                                        for i, u := range vv {
                                                fmt.Println(i, u)
                                        }
                                default:
                                        fmt.Println(k, "is of a type I don't know how to handle") 
                         }
                  }

                 //    ，      

                 var s Serverslice;
                 json.Unmarshal([]byte(result), &s)

                 fmt.Println(s.ServersID);
  
                 for i:=0; i