golang http client如何上傳和server如何接收檔案

給了一個例子，利用mime/multipart來實現client如何上傳一個檔案到server，然後server如何接受這個檔案。

看server.go代碼

package mainimport (    "io"    "os"    "fmt"    "io/ioutil"    "net/http")func uploadHandler(w http.ResponseWriter, r *http.Request) {    reader, err := r.MultipartReader()    if err != nil {        http.Error(w, err.Error(), http.StatusInternalServerError)        return    }    for {        part, err := reader.NextPart()        if err == io.EOF {            break        }        fmt.Printf("FileName=[%s], FormName=[%s]\n", part.FileName(), part.FormName())        if part.FileName() == "" {  // this is FormData            data, _ := ioutil.ReadAll(part)            fmt.Printf("FormData=[%s]\n", string(data))        } else {    // This is FileData            dst, _ := os.Create("./" + part.FileName() + ".upload")            defer dst.Close()            io.Copy(dst, part)        }    }}func main() {    http.HandleFunc("/upload", uploadHandler)    http.ListenAndServe(":8080", nil)}

例子1：client 上傳一個檔案

package mainimport (    "io"    "os"    "log"    "bytes"    "io/ioutil"    "net/http"    "mime/multipart")func main() {    bodyBuffer := &bytes.Buffer{}    bodyWriter := multipart.NewWriter(bodyBuffer)    fileWriter, _ := bodyWriter.CreateFormFile("files", "file.txt")    file, _ := os.Open("file.txt")    defer file.Close()    io.Copy(fileWriter, file)    contentType := bodyWriter.FormDataContentType()    bodyWriter.Close()    resp, _ := http.Post("http://localhost:8080/upload", contentType, bodyBuffer)    defer resp.Body.Close()    resp_body, _ := ioutil.ReadAll(resp.Body)    log.Println(resp.Status)    log.Println(string(resp_body))}

例子2：client上傳多個檔案

package mainimport (    "io"    "os"    "log"    "bytes"    "io/ioutil"    "net/http"    "mime/multipart")func main() {    bodyBuffer := &bytes.Buffer{}    bodyWriter := multipart.NewWriter(bodyBuffer)    // file1    fileWriter1, _ := bodyWriter.CreateFormFile("files", "file1.txt")    file1, _ := os.Open("file1.txt")    defer file1.Close()    io.Copy(fileWriter1, file1)    // file2    fileWriter2, _ := bodyWriter.CreateFormFile("files", "file2.txt")    file2, _ := os.Open("file2.txt")    defer file2.Close()    io.Copy(fileWriter2, file2)    contentType := bodyWriter.FormDataContentType()    bodyWriter.Close()    resp, _ := http.Post("http://localhost:8080/upload", contentType, bodyBuffer)    defer resp.Body.Close()    resp_body, _ := ioutil.ReadAll(resp.Body)    log.Println(resp.Status)    log.Println(string(resp_body))}

例子3：上傳其他Form資料

package mainimport (    "io"    "os"    "log"    "bytes"    "io/ioutil"    "net/http"    "mime/multipart")func main() {    bodyBuffer := &bytes.Buffer{}    bodyWriter := multipart.NewWriter(bodyBuffer)    // file1    fileWriter1, _ := bodyWriter.CreateFormFile("files", "file1.txt")    file1, _ := os.Open("file1.txt")    defer file1.Close()    io.Copy(fileWriter1, file1)    // file2    fileWriter2, _ := bodyWriter.CreateFormFile("files", "file2.txt")    file2, _ := os.Open("file2.txt")    defer file2.Close()    io.Copy(fileWriter2, file2)    // other form data    extraParams := map[string]string{        "title":       "My Document",        "author":      "Matt Aimonetti",        "description": "A document with all the Go programming language secrets",    }    for key, value := range extraParams {        _ = bodyWriter.WriteField(key, value)    }    contentType := bodyWriter.FormDataContentType()    bodyWriter.Close()    resp, _ := http.Post("http://localhost:8080/upload", contentType, bodyBuffer)    defer resp.Body.Close()    resp_body, _ := ioutil.ReadAll(resp.Body)    log.Println(resp.Status)    log.Println(string(resp_body))}

看server端的運行輸出：

$ go build server.go && ./serverFileName=[file1.txt], FormName=[files]FileName=[file2.txt], FormName=[files]FileName=[], FormName=[description]FormData=[A document with all the Go programming language secrets]FileName=[], FormName=[title]FormData=[My Document]FileName=[], FormName=[author]FormData=[Matt Aimonetti]$ ls -ltotal 25180-rwxr-xr-x 1 ... 6179399 Jun 22 08:07 client-rw-r--r-- 1 ...    1952 Jun 22 08:06 client.go-rw-r--r-- 1 ...      15 Jun 22 07:11 file1.txt-rw-r--r-- 1 ...      15 Jun 22 08:28 file1.txt.upload-rw-r--r-- 1 ...      14 Jun 22 07:11 file2.txt-rw-r--r-- 1 ...      14 Jun 22 08:28 file2.txt.upload-rw-r--r-- 1 ...      15 Jun 22 07:56 file.txt-rw-r--r-- 1 ...      15 Jun 22 08:10 file.txt.upload-rwxr-xr-x 1 ... 6717437 Jun 22 07:59 server-rw-r--r-- 1 ...    1580 Jun 22 07:58 server.go