Axios 实现 Excel 文件上传与下载方案详解

进阶版：多文件上传

const uploadMultipleFiles = async (fileList) => {
  const formData = new FormData();
  fileList.forEach((file, index) => {
    // 同一字段名接收数组，或不同字段名区分业务
    formData.append('files', file);
    formData.append(`fileNames[${index}]`, file.name);
  });

  try {
    const response = await axios.post('/api/upload/batch', formData,
      { headers: { 'Content-Type': undefined } }
    );
    return response.data;
  } catch (error) {
    console.error('批量上传失败:', error);
    throw error;
  }
};

带进度条的上传

利用 onUploadProgress 回调监听 XMLHttpRequest 的 progress 事件。

const uploadWithProgress = (file, onProgress) => {
  const formData = new FormData();
  formData.append('file', file);
  return axios.post('/api/upload', formData,
    {
      headers: { 'Content-Type': undefined },
      onUploadProgress: (progressEvent) => {
        const percentCompleted = Math.round((progressEvent.loaded * 100) / progressEvent.total);
        if (onProgress) onProgress(percentCompleted);
      },
      timeout: 0 // 大文件建议不设超时或设较长时间
    }
  );
};

防抖处理

防止用户重复点击导致并发请求过多。

import { debounce } from 'lodash';

const debouncedUpload = debounce(async (file, callback) => {
  try {
    const result = await uploadWithProgress(file, callback);
    return result;
  } catch (error) {
    console.error(error);
  }
}, 300, { leading: true, trailing: false });

文件下载实现

最简版：基础下载

必须设置 responseType: 'blob'，否则返回乱码字符串。

const downloadExcel = async () => {
  try {
    const response = await axios({
      url: '/api/export/user-list',
      method: 'GET',
      responseType: 'blob',
      params: { startDate: '2024-01-01', endDate: '2024-12-31' }
    });

    const blob = new Blob([response.data], {
      type: 'application/vnd.openxmlformats-officedocument.spreadsheetml.sheet'
    });
    const url = window.URL.createObjectURL(blob);
    const link = document.createElement('a');
    link.href = url;
    link.download = '用户列表.xlsx';
    document.body.appendChild(link);
    link.click();
    document.body.removeChild(link);
    window.URL.revokeObjectURL(url);
  } catch (error) {
    console.error('下载失败:', error);
  }
};

文件名解析

从响应头 Content-Disposition 中提取文件名，支持中文编码。

const downloadWithFileName = async () => {
  const response = await axios({
    url: '/api/export/report',
    method: 'POST',
    responseType: 'blob',
    data: { reportType: 'monthly' }
  });

  const contentDisposition = response.headers['content-disposition'];
  let fileName = '下载文件.xlsx';

  if (contentDisposition) {
    // 尝试匹配 filename*=UTF-8''xxx (RFC 5987)
    const utf8Match = contentDisposition.match(/filename\*=UTF-8''([^;]+)/i);
    if (utf8Match && utf8Match[1]) {
      fileName = decodeURIComponent(utf8Match[1]);
    } else {
      // 尝试普通 filename="xxx"
      const normalMatch = contentDisposition.match(/filename="([^"]+)"/i);
      if (normalMatch && normalMatch[1]) {
        fileName = normalMatch[1];
      }
    }
  }

  const blob = new Blob([response.data], { type: response.headers['content-type'] });
  const url = window.URL.createObjectURL(blob);
  const link = document.createElement('a');
  link.href = url;
  link.download = fileName;
  document.body.appendChild(link);
  link.click();
  document.body.removeChild(link);
  window.URL.revokeObjectURL(url);
};

通用下载函数封装

export const downloadFile = async (url, config = {}, defaultName = 'download') => {
  try {
    const response = await axios({ url, method: 'GET', responseType: 'blob', ...config });
    
    const contentDisposition = response.headers['content-disposition'];
    let fileName = defaultName;
    if (contentDisposition) {
      const match = contentDisposition.match(/filename\*?=(?:UTF-8'')?([^;]+)/i);
      if (match) {
        fileName = decodeURIComponent(match[1].replace(/['"]/, ''));
      }
    }

    const blob = new Blob([response.data], {
      type: response.headers['content-type'] || 'application/octet-stream'
    });
    const downloadUrl = window.URL.createObjectURL(blob);
    const link = document.createElement('a');
    link.href = downloadUrl;
    link.download = fileName;
    link.style.display = 'none';
    document.body.appendChild(link);
    link.click();

    setTimeout(() => {
      document.body.removeChild(link);
      window.URL.revokeObjectURL(downloadUrl);
    }, 100);

    return { success: true, fileName };
  } catch (error) {
    console.error('下载失败:', error);
    throw error;
  }
};

带下载进度的大文件下载

const downloadLargeFile = async (url, fileName, onProgress) => {
  const response = await axios({
    url,
    method: 'GET',
    responseType: 'blob',
    onDownloadProgress: (progressEvent) => {
      if (progressEvent.total) {
        const percent = Math.round((progressEvent.loaded * 100) / progressEvent.total);
        onProgress?.(percent);
      }
    },
    timeout: 0
  });

  const blob = new Blob([response.data]);
  const downloadUrl = window.URL.createObjectURL(blob);
  const link = document.createElement('a');
  link.href = downloadUrl;
  link.download = fileName;
  link.click();
  window.URL.revokeObjectURL(downloadUrl);
};

拦截器与错误处理

统一 Token 与错误处理

// 请求拦截器
axios.interceptors.request.use(config => {
  const token = localStorage.getItem('token');
  if (token) {
    config.headers.Authorization = `Bearer ${token}`;
  }
  return config;
});

// 响应拦截器
axios.interceptors.response.use(response => response, error => {
  if (error.response?.status === 401) {
    window.location.href = '/login';
  }
  return Promise.reject(error);
});

处理 Blob 类型的错误响应

当下载接口返回非 200 状态码时，可能返回 JSON 错误信息而非文件流。

axios.interceptors.response.use(async response => {
  if (response.config.responseType === 'blob' && response.status !== 200) {
    const text = await response.data.text();
    try {
      const error = JSON.parse(text);
      return Promise.reject(error);
    } catch {
      return Promise.reject(new Error('下载失败'));
    }
  }
  return response;
}, error => Promise.reject(error));

实际落地场景

场景一：报表导出（异步生成）

大数据量导出通常采用异步任务模式。

const exportReport = async (params) => {
  // 1. 发起导出任务
  const { data: { taskId } } = await axios.post('/api/export/task', params);

  // 2. 轮询任务状态
  const checkStatus = () => new Promise((resolve, reject) => {
    const timer = setInterval(async () => {
      try {
        const { data } = await axios.get(`/api/export/task/${taskId}/status`);
        if (data.status === 'completed') {
          clearInterval(timer);
          resolve(data.downloadUrl);
        } else if (data.status === 'failed') {
          clearInterval(timer);
          reject(new Error('生成失败'));
        }
      } catch (error) {
        clearInterval(timer);
        reject(error);
      }
    }, 2000);
  });

  try {
    const downloadUrl = await checkStatus();
    await downloadFile(downloadUrl, {}, '报表.xlsx');
  } catch (error) {
    message.error(error.message);
  }
};

场景二：批量导入 + 实时预览

先上传到预览接口，解析后展示错误行，确认无误后再正式入库。

const UploadWithPreview = () => {
  const [previewData, setPreviewData] = useState([]);
  const [errorRows, setErrorRows] = useState([]);

  const handleUpload = async (file) => {
    const formData = new FormData();
    formData.append('file', file);
    const { data } = await axios.post('/api/import/preview', formData,
      { headers: { 'Content-Type': undefined } }
    );
    setPreviewData(data.list);
    setErrorRows(data.errors);
  };

  const confirmImport = async () => {
    await axios.post('/api/import/confirm', { data: previewData });
    message.success('导入成功');
  };

  return (
    <div>
      <Upload beforeUpload={handleUpload} fileList={[]}>
        <Button>上传 Excel 预览</Button>
      </Upload>
      {/* 表格展示逻辑略 */}
    </div>
  );
};

场景三：图片压缩上传

在上传前进行本地压缩和格式校验。

import Compressor from 'compressorjs';

const compressAndUpload = (file) => {
  if (!['image/jpeg', 'image/png'].includes(file.type)) {
    message.error('只支持 jpg/png 格式');
    return;
  }
  if (file.size > 10 * 1024 * 1024) {
    message.error('图片不能超过 10MB');
    return;
  }

  new Compressor(file, {
    quality: 0.6,
    maxWidth: 1920,
    maxHeight: 1080,
    success(result) {
      const compressedFile = new File([result], file.name, { type: result.type });
      uploadFile(compressedFile);
    },
    error(err) {
      message.error('压缩失败');
    }
  });
};

常见问题排查

1. 下载乱码：检查是否设置 responseType: 'blob'，以及后端是否返回了正确的流。
2. 跨域问题：确保后端 CORS 配置包含 Access-Control-Expose-Headers: Content-Disposition。
3. 超时问题：大文件操作需调大 timeout 或设为 0。

进阶优化技巧

1. 全局上传下载管理器：使用 Context 或 Redux 管理任务队列，支持暂停、取消。
2. 拦截器统一标识：通过 X-Upload-Request 等自定义 Header 区分请求类型。
3. 文件类型校验工具：封装校验函数，限制 MIME 类型和文件大小。

总结

Axios 配合 Blob 与 FormData 是前端处理文件交互的标准方案。通过合理配置响应类型、利用拦截器统一处理鉴权与错误、并结合实际业务场景（如异步导出、断点续传需求），可以构建稳定高效的文件服务模块。