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：
Client-Get 请求
Client-Post 请求
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<len(s.Servers); i++ {
fmt.Println(s.Servers[i].ServerName)
fmt.Println(s.Servers[i].ServerIP)
}
}
}
