[golang]简单文件上传服务_语言综合

概述利用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> <

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, 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("/",newRouter())}