go语言搭建图片上传服务器

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原作者: [db:作者] 来自: [db:来源] 收藏邀请

工具： LiteIDE

配置：

代码：list.html

<!doctype html>
<html>
<head>
<meta charset="utf-8">
<title>List</title>
</head>
<body>
<ol>
{{range $.images}}
<li><a href="/view?id={{.|urlquery}}">{{.|html}}</a></li>
{{end}}
</ol>
</body>
</html>

upload.html

<!doctype html>
<html>
<head>
<meta charset="utf-8">
<title>Upload</title>
</head>
<body>
<form method="POST" action="/upload" enctype="multipart/form-data">
Choose an image to upload: <input name="image" type="file" />
<input type="submit" value="Upload" />
</form>
</body>
</html>

photoweb.go：　

// photoweb
package main

import (
	"fmt"
	"html/template"
	"io"
	"io/ioutil"
	"log"
	"net/http"
	"os"
	"path"
	"runtime/debug"
	"strings"
)

const (
	ListDir      = 0x0001
	TEMPLATE_DIR = "./view"
	UPLOAD_DIR   = "./uploads"
)

var templates map[string]*template.Template = make(map[string]*template.Template)

func init() {
	fileInfoArr, err := ioutil.ReadDir(TEMPLATE_DIR)
	check(err)
	var templateName, templatePath string
	for _, fileInfo := range fileInfoArr {
		templateName = fileInfo.Name()
		var ext string
		if ext = path.Ext(templateName); ext != ".html" {
			continue
		}
		templatePath = TEMPLATE_DIR + "/" + templateName
		log.Println("Loading template:", templatePath)
		t := template.Must(template.ParseFiles(templatePath))
		tmpl := strings.TrimSuffix(templateName, ext)
		templates[tmpl] = t
	}
}

func safeHandler(fn http.HandlerFunc) http.HandlerFunc {
	return func(w http.ResponseWriter, r *http.Request) {
		defer func() {
			if err, ok := recover().(error); ok {
				http.Error(w, err.Error(), http.StatusInternalServerError)
				// 或者输出自定义的 50x 错误页面
				// w.WriteHeader(http.StatusInternalServerError)
				// renderHtml(w, "error", e)
				// logging
				log.Println("WARN: panic in %v - %v", fn, err)
				log.Println(string(debug.Stack()))
			}
		}()
		fn(w, r)
	}
}

func check(err error) {
	if err != nil {
		panic(err)
	}
}
func renderHtml(w http.ResponseWriter, tmpl string, locals map[string]interface{}) {
	err := templates[tmpl].Execute(w, locals)
	check(err)
}

func uploadHandler(w http.ResponseWriter, r *http.Request) {
	if r.Method == "GET" {
		//io.WriteString(w, "<form method='POST' action='/upload' enctype='multipart/form-data'> Choose an image to upload: <input name='image' type='file'/> <input type='submit' value='Upload'/> </form>")
		//		t, err := template.ParseFiles("upload.html")
		//		if err != nil {
		//			http.Error(w, err.Error(), http.StatusInternalServerError)
		//			return
		//		}
		//		t.Execute(w, nil)
		//		return
		renderHtml(w, "upload", nil)

	}
	if r.Method == "POST" {
		f, h, err := r.FormFile("image")
		if err != nil {
			http.Error(w, err.Error(), http.StatusInternalServerError)
			return
		}

		filename := h.Filename
		defer f.Close()

		t, err := os.Create(UPLOAD_DIR + "/" + filename)

		if err != nil {
			http.Error(w, err.Error(), http.StatusInternalServerError)
			return
		}

		defer t.Close()

		if _, err := io.Copy(t, f); err != nil {
			http.Error(w, err.Error(), http.StatusInternalServerError)
			return
		}

		http.Redirect(w, r, "/view?id="+filename, http.StatusFound)
	}

}

func viewHandler(w http.ResponseWriter, r *http.Request) {
	imageId := r.FormValue("id")
	imagePath := UPLOAD_DIR + "/" + imageId
	w.Header().Set("Content-Type", "image")
	http.ServeFile(w, r, imagePath)
}

func isExists(path string) bool {
	_, err := os.Stat(path)
	if err == nil {
		return true
	}
	return os.IsExist(err)
}

func listHandler(w http.ResponseWriter, r *http.Request) {
	//	fileInfoArr, err := ioutil.ReadDir("./uploads")
	//	if err != nil {
	//		http.Error(w, err.Error(),
	//			http.StatusInternalServerError)
	//		return
	//	}
	//	locals := make(map[string]interface{})
	//	images := []string{}
	//	for _, fileInfo := range fileInfoArr {
	//		images = append(images, fileInfo.Name())
	//	}
	//	locals["images"] = images
	//	t, err := template.ParseFiles("list.html")
	//	if err != nil {
	//		http.Error(w, err.Error(),
	//			http.StatusInternalServerError)
	//		return
	//	}
	//	t.Execute(w, locals)

	fileInfoArr, err := ioutil.ReadDir("./uploads")
	check(err)
	locals := make(map[string]interface{})
	images := []string{}
	for _, fileInfo := range fileInfoArr {
		images = append(images, fileInfo.Name())
	}
	locals["images"] = images
	renderHtml(w, "list", locals)

}

func staticDirHandler(mux *http.ServeMux, prefix string, staticDir string, flags int) {
	mux.HandleFunc(prefix, func(w http.ResponseWriter, r *http.Request) {
		file := staticDir + r.URL.Path[len(prefix)-1:]
		if (flags & ListDir) == 0 {
			if exists := isExists(file); !exists {
				http.NotFound(w, r)
				return
			}
		}
		http.ServeFile(w, r, file)
	})
}

func main() {
	fmt.Println("Hello World!")
	mux := http.NewServeMux()
	staticDirHandler(mux, "/assets/", "./public", 0)
	mux.HandleFunc("/", safeHandler(listHandler))
	mux.HandleFunc("/view", safeHandler(viewHandler))
	mux.HandleFunc("/upload", safeHandler(uploadHandler))
	err := http.ListenAndServe(":8080", mux)
	if err != nil {
		log.Fatal("ListenAndServe: ", err.Error())
	}

}

测试：

参考：《GO 语言编程》