golang web 文件服务器 WFS

golang 使用标准库 30行代码实现 web 文件托管服务器

WFS（Web File Server） 是一个可以通过浏览器浏览本地托管目录的在线文件服务器。

使用自定义的 ResponseBodyWriter 结构在 Write 函数中重写 http.ResponseWriter 响应内容。

运行程序，访问 http://127.0.0.1:8080/ 即可访问 exe 根目录内容。

package main

import (
	"bytes"
	"log"
	"net/http"
	"os"
	"path/filepath"
)

func codeStarts() string {
	return `


    
    
    
    
    

    
    
    



	
FileServer - 驭鲸环球
    `
}

func codeEnd() string {
	return `


`
}

type ResponseBodyWriter struct {
	http.ResponseWriter
	body *bytes.Buffer
}

func (r ResponseBodyWriter) Write(b []byte) (int, error) {
	if bytes.Equal(b, []byte{60, 112, 114, 101, 62, 10} /*
*/) {
		return r.ResponseWriter.Write([]byte(codeStarts()))
	} else if bytes.Equal(b, []byte{60, 47, 112, 114, 101, 62, 10} /*
*/) {
		return r.ResponseWriter.Write([]byte(codeEnd()))
	} else if bytes.HasPrefix(b, []byte("")) {
		s := append([]byte(""), b...)
		s = append(s, []byte("")...)
		//r.body.Write(s)
		return r.ResponseWriter.Write(s)
	}
	return r.ResponseWriter.Write(b)
}

func middleware(next http.Handler) http.Handler {
	return http.HandlerFunc(func(writer http.ResponseWriter, request *http.Request) {
		w := &ResponseBodyWriter{ResponseWriter: writer, body: &bytes.Buffer{}}
		writer = w
		next.ServeHTTP(writer, request)
	})
}

func main() {
	path, _ := filepath.Abs(filepath.Dir(os.Args[0]))
	//设置wfs根目录
	//path = "D:/Games/Naraka"
	fileHandler := http.FileServer(http.Dir(path))
	http.Handle("/", middleware(fileHandler))
	err := http.ListenAndServe(":8080", nil)
	if err != nil {
		log.Println(err)
	}
}