js纯前端实现腾讯cos文件上传功能的示例代码

//监听文件变化
document.getElementById('file').onchange = function() {
          let file = this.files[0];
          let type = file.type
          //初始化文件上传
          initUploadObj(that, file.name, file, 'image', function(res) {
            if (res.success) {
              that.$message.success(res.msg)
            } else {
              that.$message.warning(res.msg)
            }
          })
        }

/**
 * 初始化上传文件对象
 * @param {object} Vue
 * @param {string} fileName 文件名
 * @param {object} file 上传的文件流及文件类型 名称相关信息
 * @param {Array} 允许上传的文件类型
 * @param {function} uploadStatusCallbalck
 * @return {function} 返回回调函数
 */
export const initUploadObj = function (Vue,fileName,file,type,uploadStatusCallbalck) {
 let fileInfo = {
  file_name: fileName,
  media_type: 2,
  media_sub_type: 0,
  size_of_bytes: 122,
  file_expired_type: 'permanent',
 };
 //前端做文件类型限制
 if(type == 'image'){
  type = ['.jpg','.gif','.jpeg','.bmp','.png']
 }
 if(type == 'excel'){
  type = ['.xlsx']
 }
 let fileType =file.name ? file.name.substring(file.name.lastIndexOf(".")).toLowerCase() : ''; 
 if (!!type && type.indexOf (fileType) < 0) {
  uploadStatusCallbalck ({success: false, msg: '请上传正确的'+type+'文件格式!'});
  return;
 }
 var cos = new COS ({
  getAuthorization: function (options, callback) {
   let singleInfo = Vue.$store.state.fileToken;
   callback ({
    TmpSecretId: singleInfo.tmpSecretId,
    TmpSecretKey: singleInfo.tmpSecretKey,
    XCosSecurityToken: singleInfo.sessionToken,
    ExpiredTime: singleInfo.expiredTime,
   });
  },
 });
 fileInfo.file_name = file.name;
 //获取文件上传密钥
 getFileToken (Vue, fileInfo, cos, file, uploadStatusCallbalck);
};

function getFileToken (Vue, fileInfo, cos, file, uploadStatusCallbalck) {
 let url = process.env.VUE_APP_URL + '/file/secretid';
 if (!file) return;
 // 异步获取临时密钥
 axios
  .get (url)
  .then (function (res) {
   if (res.data.code == 100000) {
    //获取的临时秘钥存储在vuex中
    Vue.$store.commit ('UPDATE_FILE_INFO', res.data.data);
    uploadFile (cos, file, res.data.data, uploadStatusCallbalck);
   } else {
    uploadStatusCallbalck ({success: false, msg: '获取文件秘钥失败!'});
   }
  })
  .catch (function (err) {
   uploadStatusCallbalck ({success: false, msg: '获取文件秘钥接口出错!'});
  });
}

/**
 * @method uploadFile
 * @param {object} cos
 */
function uploadFile (cos, file, signInfo, callback) {
 cos.putObject (
  {
   Bucket: process.env.VUE_APP_BUCKET,
   Region: 'ap-shanghai',
   Key: signInfo.fileId,
   Body: file,
   onHashProgress: function (progressData) {
    console.log ('校验中', JSON.stringify (progressData));
   },
   onProgress: function (progressData) {
    console.log ('上传中', JSON.stringify (progressData));
   },
  },
  function (err, data) {
   if (err) {
    console.log (err);
    callback ({success: false, msg: '文件上传失败!'});
    return;
   }
   callback ({success: true, msg: '上传成功!', data: data, signInfo: signInfo});
  }
 );
}