# Rails控制器示例
def upload
  uploaded_file = params[:file] # 假设表单字段名为file
  file_content = uploaded_file.read # 读取文件内容为字符串
  
  # 处理文件内容...
end

File.open(uploaded_file.path) do |file|
  while line = file.gets
    # 逐行处理文件内容
  end
end

def upload
  uploaded_file = params[:file]
  
  # 使用Active Storage (Rails 5.2+)
  blob = ActiveStorage::Blob.create_and_upload!(
    io: uploaded_file,
    filename: uploaded_file.original_filename,
    content_type: uploaded_file.content_type
  )
  
  # 或者保存到特定目录
  File.open(Rails.root.join('public', 'uploads', uploaded_file.original_filename), 'wb') do |file|
    file.write(uploaded_file.read)
  end
end

def upload
  begin
    uploaded_file = params[:file]
    raise "No file uploaded" unless uploaded_file
    
    # 检查文件类型
    unless ['image/jpeg', 'image/png'].include?(uploaded_file.content_type)
      raise "Invalid file type"
    end
    
    # 处理文件...
  rescue => e
    render json: { error: e.message }, status: :unprocessable_entity
  end
end