golang之net/http模块学习

开启服务

package main

import (
	"fmt"
	"net/http"
)

//路由
func handler(w http.ResponseWriter, r *http.Request){
	fmt.Fprintf(w, "hello World!")
}

func main(){
	//路由
	http.HandleFunc("/", handler)
  	//开启服务
	http.ListenAndServe(":8091", nil) //port:8091(自定义,注意:要是空闲端口)
}

#启动服务
go run main.go

这样本地的8091端口就可以访问了

开启访问静态文件

我们这里拿video来举例

package main

import (
  "fmt"
  "net/http"
)

func main(){
  	//静态文件访问
	fs := http.FileServer(http.Dir("./assets"))
	http.Handle("/static/", http.StripPrefix("/static/", fs))
	//开启服务
	http.ListenAndServe(":8091", nil)
}

按照图上的访问路径(http://localhost:8091/static/video/20231204-134423.mp4)

获取现在时间

package main

import (
  "fmt"
  "time"
)

func main(){
	currentTime := time.Now()
	fmt.Println("当前的时间为",currentTime)
}

因为currentTime是time.Time类型所以要想页面输出要进行字符串转换

//获取时间
func getNowTime(w http.ResponseWriter, r *http.Request){
	currentTime := time.Now()
	timeString := currentTime.Format("2006-01-02 15:04:05")//"2006-01-02 15:04:05"只是时间格式化字符串格式
	fmt.Fprintf(w,timeString)
}

至于这个函数上面命名也是如此,就当是net/http路由服务的固定格式便好
注意: Golang函数首字符大写代表着公开(public)小写代表着私有(private)

按时间创建一个空的json文件

package main

import (
	"fmt"
	"time"
//	"encoding/json"
	"os"
)

func CreateFileNil(){
	currentTime := GetTime()
	fileName := currentTime.Format("2006-01-02_15-04-05") + ".json"
	file,err := os.Create("./assets/json/"+fileName)
	if err != nil {
		fmt.Println("JSON编码失败:", err)
		return
	}
	defer file.Close() //defer:表示函数的最后执行(这里是确保最后文件是关闭的)
}

func main(){
	CreateFileNil()
}

按时间创建一个固定值的json文件

package main

import (
	"fmt"
	"time"
	"encoding/json"
	"os"
)

type Person struct {
	Name string
	Age int
}
//创建一个固定值的json文件
func CreateFileGuDin(){
	currentTime := GetTime()
	fileName := currentTime.Format("2006-01-02_15-04-05") + ".json"
	file,err := os.Create("./assets/json/"+fileName)
	if err != nil {
		fmt.Println("JSON编码失败:", err)
		return
	}
	defer file.Close()
	
	person := Person{Name: "Alice", Age: 25}
	jsonData, err := json.Marshal(person)
	if err != nil {
		fmt.Println("JSON编码失败:", err)
		return
	}

	_, err = file.Write(jsonData)
	if err != nil {
		fmt.Println("写入文件失败:", err)
		return
	}

	fmt.Println("JSON文件创建成功:", fileName)
}

func main(){
  CreateFileGuDin()
}

跨域请求处理

package main

import (
	"fmt"
	"net/http"
)

//路由
func handler(w http.ResponseWriter, r *http.Request){
	fmt.Fprintf(w, "hello World!")
}

func main(){
	//创建一个处理跨域请求的处理器函数
	corsHandler := func(h http.Handler) http.Handler {
		return http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
			// 设置允许跨域的域名
			w.Header().Set("Access-Control-Allow-Origin", "*")
			// 允许的请求方法
			w.Header().Set("Access-Control-Allow-Methods", "GET, POST, PUT, DELETE, OPTIONS")
			// 允许的请求头
			w.Header().Set("Access-Control-Allow-Headers", "Content-Type, Authorization")
			// 如果是预检请求，直接返回
			if r.Method == "OPTIONS" {
				return
			}
			h.ServeHTTP(w, r)
		})
	}
	//路由
	http.Handle("/", corsHandler(http.HandlerFunc(handler)))

	//开启服务
	http.ListenAndServe(":8091", nil)
}

输出是json

package main

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

type FileDetail struct{
  NowTime string `json:"now_time"`
  FileName string `json:"file_name"`
}

func func_name1(w http.ResponseWriter, r *http.Request){
  responseData := FileDetail {NowTime:"2023_12_04_22_51_30.json",FileName:"http://"+local+":" + port + "/static/video/20231204-19.mp4"}
  w.Header().Set("Content-Type", "application/json")
  w.WriteHeader(http.StatusOK)
  json.NewEncoder(w).Encode(responseData)
}

func main(){
  //创建一个处理跨域请求的处理器函数
	corsHandler := func(h http.Handler) http.Handler {
		return http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
			// 设置允许跨域的域名
			w.Header().Set("Access-Control-Allow-Origin", "*")
			// 允许的请求方法
			w.Header().Set("Access-Control-Allow-Methods", "GET, POST, PUT, DELETE, OPTIONS")
			// 允许的请求头
			w.Header().Set("Access-Control-Allow-Headers", "Content-Type, Authorization")
			// 如果是预检请求，直接返回
			if r.Method == "OPTIONS" {
				return
			}
			h.ServeHTTP(w, r)
		})
	}
    
    http.Handle("/test", corsHandler(http.HandlerFunc(func_name1)))
    //开启服务
	http.ListenAndServe(":8091", nil)
}