Golang多文件并发上传实现详解

func uploadFile(filePath, url, fieldName string) error {
    file, err := os.Open(filePath)
    if err != nil {
        return err
    }
    defer file.Close()
body := &bytes.Buffer{}
writer := multipart.NewWriter(body)
part, err := writer.CreateFormFile(fieldName, filepath.Base(filePath))
if err != nil {
    return err
}
_, err = io.Copy(part, file)
if err != nil {
    return err
}

err = writer.Close()
if err != nil {
    return err
}

req, err := http.NewRequest("POST", url, body)
if err != nil {
    return err
}
req.Header.Set("Content-Type", writer.FormDataContentType())

client := &http.Client{}
resp, err := client.Do(req)
if err != nil {
    return err
}
defer resp.Body.Close()

if resp.StatusCode != http.StatusOK {
    return fmt.Errorf("upload failed: %s", resp.Status)
}
return nil
}

files := []string{"file1.jpg", "file2.pdf", "file3.txt"}
url := "https://example.com/upload"
sem := make(chan struct{}, 5) // 控制最大并发数为5
errCh := make(chan error, len(files))
for _, f := range files {
go func(filePath string) {
sem <- struct{}{} // 获取信号量
defer func() { <-sem }()
    err := uploadFile(filePath, url, "file")
    if err != nil {
        errCh <- fmt.Errorf("%s: %w", filePath, err)
        return
    }
    errCh <- nil
}(f)
}
// 等待所有任务完成
for i := 0; i < len(files); i++ {
if err := <-errCh; err != nil {
log.Printf("Upload error: %v", err)
}
}

client := &http.Client{
    Timeout: 30 * time.Second,
}