[Go]處理請求

發佈於後端

更新於 2024/05/20發佈於 2024/01/02閱讀時間約 13 分鐘

Request內容

package main

import (
	"fmt"
	"log"
	"net/http"
	"strings"
)

func request(w http.ResponseWriter, r *http.Request) {
	//這些資訊是輸出到伺服器端的列印訊息
	fmt.Println("Request解析")
	//HTTP方法
	fmt.Println("method", r.Method)
	//RequestURI是被客戶端傳送到服務端的請求的請求行中未修改的請求URI
	fmt.Println("RequestURI:", r.RequestURI)
	//URL類型,下方分別列出URL的各成員
	fmt.Println("URL_path", r.URL.Path)
	fmt.Println("URL_RawQuery", r.URL.RawQuery)
	fmt.Println("URL_Fragment", r.URL.Fragment)
	//協定版本
	fmt.Println("proto", r.Proto)
	fmt.Println("protomajor", r.ProtoMajor)
	fmt.Println("protominor", r.ProtoMinor)
	//HTTP請求的頭域
	for k, v := range r.Header {
		for _, vv := range v {
			fmt.Println("header key:" + k + "  value:" + vv)
		}
	}
	//判斷是否multipart方式
	isMultipart := false
	for _, v := range r.Header["Content-Type"] {
		if strings.Index(v, "multipart/form-data") != -1 {
			isMultipart = true
		}
	}
	//解析body
	if isMultipart == true {
		r.ParseMultipartForm(128)
		fmt.Println("解析方式:ParseMultipartForm")
	} else {
		r.ParseForm()
		fmt.Println("解析方式:ParseForm")
	}
	//body內容長度
	fmt.Println("ContentLength", r.ContentLength)
	//是否在回覆請求後關閉連接
	fmt.Println("Close", r.Close)
	//HOSt
	fmt.Println("host", r.Host)
	//該請求的來源位址
	fmt.Println("RemoteAddr", r.RemoteAddr)

	fmt.Fprintf(w, "hello, let's go!") 
	//這個寫入到w的是輸出到客戶端的
}
func main() {
	http.HandleFunc("/hello", request)
	err := http.ListenAndServe(":8081", nil)
	if err != nil {
		log.Fatal("ListenAndServe:", err)
	}
}

URL內容

package main

import "net/url"

func main() {
	path := "http://lcoalhost:8082/article?id=1"
	p, _ := url.Parse(path) // 解析url
	println(p.Host)//lcoalhost:8082
	println(p.User)//0x0
	println(p.RawQuery)//id=1
	println(p.RequestURI())///article?id=1
}

請求的內容

package main

import (
	"fmt"
	"net/http"
)

func getBody(w http.ResponseWriter, r *http.Request) {
	//取得請求訊息的內容長度
	len := r.ContentLength
	//新建一個位元組切片，長度與請求封包的內容長度相同
	body := make([]byte, len)
	//讀取r的請求主體，並將具體內容讀入body中
	r.Body.Read(body)
	//將位元組切片內容寫入對應報文
	fmt.Fprintln(w, string(body))
}
func main() {
	http.HandleFunc("/getBody", getBody)
	err := http.ListenAndServe(":8082", nil)
	if err != nil {
		fmt.Println(err)
	}
}

Form與PostForm

package main

import (
	"fmt"
	"html/template"
	"io/ioutil"
	"net/http"
)

func process(w http.ResponseWriter, r *http.Request) {
	if r.Method == "GET" {
		t, _ := template.ParseFiles("form.html")
		t.Execute(w, nil)
	} else {
		r.ParseForm()//語法分析
		fmt.Fprintln(w, "表單鍵值對和URL鍵值對：", r.Form)
		fmt.Fprintln(w, "表單鍵值對：", r.PostForm)
	}
}

func main() {
	http.HandleFunc("/", process) 
	http.ListenAndServe(":8089", nil)
}

MultipartForm

package main

import (
	"fmt"
	"html/template"
	"io/ioutil"
	"net/http"
)

func multiProcess(w http.ResponseWriter, r *http.Request) {
	if r.Method == "GET" {
		t, _ := template.ParseFiles("form.html")
		t.Execute(w, nil)
	} else {
		r.ParseMultipartForm(1024)//從表單中提取多少位元組的數據
		fmt.Fprintln(w,"表单键值对:", r.MultipartForm)
	}
}

func main() {
	http.HandleFunc("/", multiProcess)
	http.ListenAndServe(":8089", nil)
}

上傳檔案

package main

import (
	"fmt"
	"html/template"
	"io/ioutil"
	"net/http"
)

//上傳
func upload(w http.ResponseWriter, r *http.Request) {
	if r.Method == "GET" {
		t, _ := template.ParseFiles("upload.html")
		t.Execute(w, nil)
	} else {
		r.ParseMultipartForm(4096)
		fileHeader := r.MultipartForm.File["uploaded"][0]//取得名為"uploaded"的第一個檔案頭

		file, err := fileHeader.Open()//取得文件
		if err != nil {
			fmt.Println("error")
			return
		}
		data, err := ioutil.ReadAll(file)//讀取文件
		if err != nil {
			fmt.Println("error!")
			return
		}
		fmt.Fprintln(w, string(data))
	}
}

func main() {
	http.HandleFunc("/", upload)
	http.ListenAndServe(":8089", nil)
}

WriteHeader()與Header()

package main

import (
	"fmt"
	"net/http"
)

func Redirect(w http.ResponseWriter, r *http.Request)  {
	//設定一個301重定向
	w.Header().Set("Location", "https://www.xxx.com")
	w.WriteHeader(301)
}

func main() {
	http.HandleFunc("/redirect", Redirect)
	err := http.ListenAndServe(":8086", nil)
	if err != nil {
		fmt.Println(err)
	}
}

這邊要注意w.Header().Set()與w.WriteHeader()的使用順序。

Write()

字串

package main

import (
	"fmt"
	"net/http"
)

func Welcome(w http.ResponseWriter, r *http.Request)  {
	w.Write([]byte("Go go！"))
}

func main() {
	http.HandleFunc("/welcome", Welcome)
	err := http.ListenAndServe(":8086", nil)
	if err != nil {
		fmt.Println(err)
	}
}

HTML

package main

import (
	"fmt"
	"net/http"
)

func Home(w http.ResponseWriter, r *http.Request)  {
	html := `<html> 
        <head>
            <title>Write()內容為HTML</title>
        </head> 
        <body>
            <h1>Go go go
        </body> 
    </html>`
	w.Write([]byte(html))
}

func main() {
	http.HandleFunc("/", Home)
	err := http.ListenAndServe(":8086", nil)
	if err != nil {
		fmt.Println(err)
	}
}

JSON

package main

import (
	"encoding/json"
	"fmt"
	"net/http"
)

type JsonData struct {
	Message string `json:"message"`
}
func Hello(w http.ResponseWriter, r *http.Request)  {
	//返回JSON格式
	jsonData := JsonData{
		"Go go",
	}
	message, _ := json.Marshal(jsonData)
	w.Header().Set("Content-Type", "application/json")
	w.Write(message)
}

func main() {
	http.HandleFunc("/", Hello)
	err := http.ListenAndServe(":8086", nil)
	if err != nil {
		fmt.Println(err)
	}
}