Go图片上传

使用Go语言实现图片上传功能，服务器及客户端的源代码。

服务器端代码：

// uploadfile_server.go
package main

import (
	//"crypto/md5"
	"fmt"
	//	"html/template"
	"io"
	"log"
	"net/http"
	"os"
	//	"strconv"
	//"time"
)

//检查目录是否存在
func checkFileIsExist(filename string) bool {
	var exist = true
	if _, err := os.Stat(filename); os.IsNotExist(err) {
		fmt.Print(filename + " not exist")
		exist = false
	}
	return exist
}

func main() {

	http.HandleFunc("/upload", upload)

	err := http.ListenAndServe(":9090", nil) //设置监听的端口
	if err != nil {
		log.Fatal("ListenAndServe: ", err)
	}

	log.Println("success!")
}

// 处理/upload 逻辑
func upload(w http.ResponseWriter, r *http.Request) {
	fmt.Println("method:", r.Method) //获取请求的方法
	/*if r.Method == "GET" {
		crutime := time.Now().Unix()
		h := md5.New()
		io.WriteString(h, strconv.FormatInt(crutime, 10))
		token := fmt.Sprintf("%x", h.Sum(nil))

		t, _ := template.ParseFiles("upload.gtpl")
		t.Execute(w, token)
	} else */
	fmt.Println(r)
	if r.Method == "POST" {
		r.ParseMultipartForm(32 << 20)
		file, handler, err := r.FormFile("uploadfile")
		if err != nil {
			fmt.Println(err)
			return
		}
		defer file.Close()
		fmt.Fprintf(w, "%v", handler.Header)

		//
		bool_fileexist := checkFileIsExist("./test")
		fmt.Println("check file 1-----------------")
		fmt.Println("-------------------------bool_fileexist:", bool_fileexist)
		if bool_fileexist { //如果文件夹存在
			//f, err1 = os.OpenFile(filename, os.O_APPEND, 0666) //打开文件
			f, err := os.OpenFile("./test/"+handler.Filename, os.O_WRONLY|os.O_CREATE, 0666)
			if err != nil {
				fmt.Println(err)
				return
			}
			defer f.Close()
			io.Copy(f, file)
			fmt.Println("文件夹存在")
		} else { //不存在文件夹时 先创建文件夹再上传
			err1 := os.Mkdir("./test", os.ModePerm) //创建文件夹
			if err1 != nil {
				fmt.Println(err)
				return
			}

			fmt.Println("文件夹不存在")
			fmt.Println("文件夹创建成功！")
			f, err := os.OpenFile("./test/"+handler.Filename, os.O_WRONLY|os.O_CREATE, 0666)
			if err != nil {
				fmt.Println(err)
				return
			}
			defer f.Close()
			io.Copy(f, file)
		}

	}
}

客户端代码：

// uploadfile_client.go
package main

import (
	"bytes"
	"fmt"
	"io"
	"io/ioutil"
	"mime/multipart"
	"nettp"
	"os"
)

func postFile(filename string, targetUrl string) error {
	bodyBuf := &bytes.Buffer{}
	bodyWriter := multipart.NewWriter(bodyBuf)

	//关键的一步操作
	fileWriter, err := bodyWriter.CreateFormFile("uploadfile", filename)
	if err != nil {
		fmt.Println("error writing to buffer")
		return err
	}

	//打开文件句柄操作
	fh, err := os.Open(filename)
	if err != nil {
		fmt.Println("error opening file")
		return err
	}
	defer fh.Close()

	//iocopy
	_, err = io.Copy(fileWriter, fh)
	if err != nil {
		return err
	}

	contentType := bodyWriter.FormDataContentType()
	bodyWriter.Close()

	resp, err := http.Post(targetUrl, contentType, bodyBuf)
	fmt.Println(bodyBuf)
	if err != nil {
		return err
	}
	defer resp.Body.Close()
	resp_body, err := ioutil.ReadAll(resp.Body)
	if err != nil {
		return err
	}
	fmt.Println(resp.Status)
	fmt.Println(string(resp_body))
	return nil
}

// sample usage
func main() {
	target_url := "http://xxx.xxx.xxx.xxx:9090/upload"//此处为自己的ip地址
	filename := "image2.jpg"
	postFile(filename, target_url)
}

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