Go上传文件

简介

Go提供的net/http和mime/multipart两个包可以很容易的实现http文件上传。

客户端

package mainimport (    "bytes"    "io"    "log"    "mime/multipart"    "net/http"    "os")func main() {    // 创建表单文件    // CreateFormFile 用来创建表单，第一个参数是字段名，第二个参数是文件名    buf := new(bytes.Buffer)    writer := multipart.NewWriter(buf)    formFile, err := writer.CreateFormFile("uploadfile", "test.jpg")    if err != nil {        log.Fatalf("Create form file failed: %s\n", err)    }    // 从文件读取数据，写入表单    srcFile, err := os.Open("test.jpg")    if err != nil {        log.Fatalf("%Open source file failed: s\n", err)    }    defer srcFile.Close()    _, err = io.Copy(formFile, srcFile)    if err != nil {        log.Fatalf("Write to form file falied: %s\n", err)    }    // 发送表单    contentType := writer.FormDataContentType()    writer.Close() // 发送之前必须调用Close()以写入结尾行    _, err = http.Post("http://localhost:9090/upload", contentType, buf)    if err != nil {        log.Fatalf("Post failed: %s\n", err)    }}

服务器端

package mainimport (    "io"    "log"    "net/http"    "os")func main() {    http.HandleFunc("/upload", uploadHandle)    log.Fatal(http.ListenAndServe(":9090", nil))}func uploadHandle(w http.ResponseWriter, r *http.Request) {    // 根据字段名获取表单文件    formFile, header, err := r.FormFile("uploadfile")    if err != nil {        log.Printf("Get form file failed: %s\n", err)        return    }    defer formFile.Close()    // 创建保存文件    destFile, err := os.Create("." + r.URL.Path + "/" + header.Filename)    if err != nil {        log.Printf("Create failed: %s\n", err)        return    }    defer destFile.Close()    // 读取表单文件，写入保存文件    _, err = io.Copy(destFile, formFile)    if err != nil {        log.Printf("Write file failed: %s\n", err)        return    }}