在angularjs中验证文件上传

<input type="file" ng-model="file" />

$scope.uploadFile = function() {
  var formData = new FormData();
  formData.append('file', $scope.file);

  $http.post('/upload', formData, {
    transformRequest: angular.identity,
    headers: {'Content-Type': undefined}
  }).then(function(response) {
    // 处理上传成功的逻辑
  }, function(error) {
    // 处理上传失败的逻辑
  });
};

app.post('/upload', function(req, res) {
  var file = req.files.file;

  // 验证文件类型和大小
  if (file.mimetype !== 'image/jpeg' || file.size > 1024 * 1024) {
    return res.status(400).send('Invalid file');
  }

  // 保存文件到服务器或云存储
  file.mv('uploads/' + file.name, function(error) {
    if (error) {
      return res.status(500).send('Error uploading file');
    }

    res.send('File uploaded successfully');
  });
});