rails文件上传下载和删除 .

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Model中的部分:

class SystemUploadfile < ActiveRecord::Base
  Region = ["北京","西安"]
  File_extname = [".rar",".7z",".zip"]
  File_target = "public/files"
  cattr_accessor :per_page
  @@per_page = 10
  validates :title,:presence=>true
  validates :area,:presence=>true
  validates :file_name,:presence=>true
  validates :file_url,:presence => true
  validates_format_of :file_url,
    :with => %r{/.(rar|zip|7z)}i

  def set_file_values(file_url,file_name)
    self.file_url = file_url
    self.file_name = file_name
  end

  def add_download_count
    self.counts += 1
    self.save
  end

  def get_file_path
    return SystemUploadfile::File_target+"/"+ self.file_url
  end

  #删除文件
  def delete_file
    file_path = File.join(Rails.root,SystemUploadfile::File_target,self.file_url)
    if File.exist?(file_path)
      File.delete(file_path)
    end
  end
end

Action中的部分如下：

class SystemUploadfilesController < ApplicationController
 
  def index
    @search = SystemUploadfile.search(params[:search]).order('id')
    @system_uploadfiles = @search.paginate(:page => params[:page],:per_page => SystemUploadfile.per_page)
  end
 
  def new
    @system_uploadfile = SystemUploadfile.new
    respond_to do |format|
      format.html # new.html.erb
      format.xml  { render :xml => @system_uploadfile }
    end
  end

  def create
    #如果说什么也没有接收到
    if request.get?
      @system_uploadfile = SystemUploadfile.new
      flash.now[:notice] = "文件上传失败"
      render :action => "new"
    else
      @system_uploadfile = SystemUploadfile.new(params[:system_uploadfile])
      #获取上传的文件
      uploaded_file = params[:system_uploadfile][:file_url]
      if_succ,filepath = upload_file(uploaded_file,SystemUploadfile::File_extname,SystemUploadfile::File_target)
      if if_succ
        @system_uploadfile.set_file_values(filepath, uploaded_file.original_filename)
        if @system_uploadfile.save
          redirect_to system_uploadfiles_path,:notice => "文件上传成功"
        else
          render :action => "new"
        end
      else
        flash.now[:notice] = filepath
        render :action => "new"
      end
    end
  end

  def download
    @system_uploadfile = SystemUploadfile.find_by_id(params[:id])
    if @system_uploadfile == nil
      redirect_to system_uploadfiles_path, :notice => '没有记录，下载失败！'
    else
      file_path = @system_uploadfile.get_file_path
      if File.exist?(file_path)
        #@system_uploadfile.add_download_count
        #send_file file_path,:disposition => 'inline'
        io = File.open(file_path)
        io.binmode
        send_data(io.read,:filename => @system_uploadfile.file_name,:disposition => 'attachment')
        io.close
      else
        redirect_to system_uploadfiles_path, :notice => '文件不存在，下载失败！'
      end
    end
  end
 
  def destroy
    @system_uploadfile =  SystemUploadfile.find_by_id(params[:id])
    if @system_uploadfile == nil
      flash.now[:notice] = '该记录已被删除'
      redirect_to system_uploadfiles_path
    else
      @system_uploadfile.delete_file
        @system_uploadfile.destroy
        respond_to do |format|
          format.html { redirect_to(system_uploadfiles_path) }
          format.xml  { head :ok }
        end
    end
  end
end
Form：html部分

<% form_for( @system_uploadfile,:html=>{:multipart => true}) do |f| -%>
  <%= f.label :title, "标题：" %>
 

  <%= f.text_field :title%>
  <%= f.error_message_on :title %>
 

  <%= f.label "区域" %>
  <%= f.select :area,options_for_select(SystemUploadfile::Region) %>
 


  选择上传文件:


  <%= file_field(:system_uploadfile, :file_url)%>
  <%= f.error_message_on :file_url %>
 

  <%= f.submit "提交", :disable_with => '提交中...'%>
<% end -%>

程序中用到的一个方法：

 def upload_file(file,extname,target_dir)
    if file.nil? || file.original_filename.empty?
      return false,"空文件或者文件名错误"
    else
      timenow = Time.now
      filename = file.original_filename  #file的名字
      fileloadname = timenow.strftime("%d%H%M%S")+filename #保存在文件夹下面的上传文件的名称

      if extname.include?(File.extname(filename).downcase)
        #创建目录
        #首先获得当前项目所在的目录+文件夹所在的目录
        path = Rails.root.join(target_dir,timenow.year.to_s,timenow.month.to_s)
        #生成目录
        FileUtils.makedirs(path)
        File.open(File.join(path,fileloadname),"wb") do |f|
          f.write(file.read)
          return true,File.join(timenow.year.to_s,timenow.month.to_s,fileloadname)
        end
      else
        return false,"必须是#{extname}类型的文件"
      end
    end
  end

 

 

 

from:http://blog.csdn.net/xuchao111/article/details/6333605