Golang Web编程的Get和Post请求发送与解析

http://blog.csdn.net/typ2004/article/details/38669949

本文的是一篇入门文章，通过一个简单的例子介绍Golang的Web编程主要用到的技术。

          文章结构包括：

1. Client-Get 请求 
   
2. Client-Post 请求
   
3. Server 处理 Get 和 Post 数据

          在数据的封装中，我们部分采用了json，因而本文也涉及到Golang中json的编码和解码。

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() //解析参数，默认是不会解析的
         fmt.Fprintf(w, "Hi, I love you %s", html.EscapeString(r.URL.Path[1:]))
         if r.Method == "GET" {
                 fmt.Println("method:", r.Method) //获取请求的方法

                 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\n", result)

                 //未知类型的推荐处理方法

                 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")
                          }
                   }

                  //结构已知，解析到结构体

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

                  fmt.Println(s.ServersID);

                  for i:=0; i
                          fmt.Println(s.Servers[i].ServerName)
                          fmt.Println(s.Servers[i].ServerIP)
                  }
         }
 }