golang http client如何上传和server如何接收文件

给了一个例子,利用mime/multipart来实现client如何上传一个文件到server,然后server如何接受这个文件。

看server.go代码

package main
import (
 "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 上传一个文件

package main
import (
 "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上传多个文件

package main
import (
 "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:上传其他Form数据

package main
import (
 "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端的运行输出:

$ go build server.go && ./server
FileName=[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 -l
total 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

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