文件下载注意的地方

                //设置响应头response.setContentType("application/force-download");//给客户端传送文件名String aa="湖南aa.zip";aa=URLEncoder.encode(aa,"utf-8");response.setHeader("Content-Disposition", "attachment;filename=\""+aa+"\"");//需要加这个attachment,不然成了浏览String fileName=request.getParameter("fileName");fileName=this.getServletContext().getRealPath(fileName);InputStream in=new FileInputStream(fileName);OutputStream out=response.getOutputStream();byte b[]=new byte[1024];int len=0;while((len=in.read(b))!=-1){               out.write(b,0,len);  }

流的使用，输入输出流，中文要编码   aa=URLEncoder.encode(aa,"utf-8");要获取协议头