[golang]简单文件上传服务

来源：互联网发布：linux 安装eclipse 编辑：程序博客网时间：2024/05/21 15:34

利用net/http库及gorilla/mux库实现了一个简单的文件上传服务,
示例如下:

package mainimport (    "fmt"    "github.com/gorilla/mux"    "io"    "net/http"    "os")const uploadHTML = `<html>    <head>      <title>选择文件</title>  </head>    <body>      <form enctype="multipart/form-data" action="/" method="post">        <input type="file" name="uploadfile" />        <input type="submit" value="上传文件" />      </form>    </body>  </html>`const destLocalPath = "/data/files/"func index(w http.ResponseWriter, r *http.Request) {    w.Write([]byte(uploadHTML))}func upload(w http.ResponseWriter, r *http.Request) {    if r.Method == "GET" {        index(w, r)        return    }    r.ParseMultipartForm(32 << 20) // max memory is set to 32MB    clientfd, handler, err := r.FormFile("uploadfile")    if err != nil {        fmt.Println(err)        w.Write([]byte("upload failed."))        return    }    defer clientfd.Close()    localpath := fmt.Sprintf("%s%s", destLocalPath, handler.Filename)    localfd, err := os.OpenFile(localpath, os.O_WRONLY|os.O_CREATE, 0666)    if err != nil {        fmt.Println(err)        w.Write([]byte("upload failed."))        return    }    defer localfd.Close()    io.Copy(localfd, clientfd)    w.Write([]byte("upload finish."))}func newRouter() http.Handler {    hdl := mux.NewRouter()    hdl.HandleFunc("/", upload)    return hdl}func main() {    http.ListenAndServe(":8877", newRouter())}

假如需要在接收文件的时候计算文件hash值，应该如何做呢？
根据io.TeeReader库，可以在文件上传过程中自动计算hash值, 完整代码修改为:

package mainimport (    "crypto/sha1"    "encoding/hex"    "fmt"    "github.com/gorilla/mux"    "io"    "net/http"    "os")const uploadHTML = `<html>    <head>      <title>选择文件</title>  </head>    <body>      <form enctype="multipart/form-data" action="/" method="post">        <input type="file" name="uploadfile" />        <input type="submit" value="上传文件" />      </form>    </body>  </html>`const destLocalPath = "/data/files/"func index(w http.ResponseWriter, r *http.Request) {    w.Write([]byte(uploadHTML))}func upload(w http.ResponseWriter, r *http.Request) {    if r.Method == "GET" {        index(w, r)        return    }    r.ParseMultipartForm(32 << 20) // max memory is set to 32MB    clientfd, handler, err := r.FormFile("uploadfile")    if err != nil {        fmt.Println(err)        w.Write([]byte("upload failed."))        return    }    defer clientfd.Close()    localpath := fmt.Sprintf("%s%s", destLocalPath, handler.Filename)    localfd, err := os.OpenFile(localpath, os.O_WRONLY|os.O_CREATE, 0666)    if err != nil {        fmt.Println(err)        w.Write([]byte("upload failed."))        return    }    defer localfd.Close()    // 利用io.TeeReader在读取文件内容时计算hash值    fhash := sha1.New()    io.Copy(localfd, io.TeeReader(clientfd, fhash))    hstr := hex.EncodeToString(fhash.Sum(nil))    w.Write([]byte(fmt.Sprintf("upload finish:%s", hstr)))}func newRouter() http.Handler {    hdl := mux.NewRouter()    hdl.HandleFunc("/", upload)    return hdl}func main() {    http.ListenAndServe(":8877", newRouter())}

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