以id为参数进行文件下载

controller

    @RequestMapping("downloadFile")
    public void downloadData(Long id, HttpServletRequest request, HttpServletResponse response) throws IOException {
        DataRadarFarStation dataRadarFarStation = dataRadarFarStationService.selectDataRadarFarStationById(id);
        //要下载的文件名 从前台传来
        String fileNameNeedDown = dataRadarFarStation.getFileName();
        //这里的路径是要下载的文件所在路径
        String realPath = dataRadarFarStation.getFilePath();
        File file = null;
        file = new File(realPath);

        BufferedInputStream bis = null;
        BufferedOutputStream bos = null;
        try {
            String aFileName = null;
            request.setCharacterEncoding("UTF-8");
            String agent = request.getHeader("User-Agent").toUpperCase();
            if ((agent.indexOf("MSIE") > 0)
                    || ((agent.indexOf("RV") != -1) && (agent
                    .indexOf("FIREFOX") == -1))) {
                aFileName = URLEncoder.encode(fileNameNeedDown, "UTF-8");
            } else {
                aFileName = new String(fileNameNeedDown.getBytes("UTF-8"), "ISO8859-1");
            }
            response.setContentType("application/octet-stream");
            response.setHeader("Content-disposition", "attachment; filename="
                    + aFileName);
            response.setHeader("Content-Length", String.valueOf(file.length()));
            bis = new BufferedInputStream(new FileInputStream(new File(realPath)));
            bos = new BufferedOutputStream(response.getOutputStream());
            byte[] buff = new byte[2048];
            int bytesRead;
            while (-1 != (bytesRead = bis.read(buff, 0, buff.length))) {
                bos.write(buff, 0, bytesRead);
            }
            System.out.println("success");
            bos.flush();
        } catch (Exception e) {
            System.out.println("失败！");
        } finally {
            try {
                if (bis != null) {
                    bis.close();
                }
                if (bos != null) {
                    bos.close();
                }
            } catch (Exception e) {
            }
        }
    }

service

public  DataRadarFarStation   selectDataRadarFarStationById(String id)


impl

    @Override
    public DataRadarFarStation selectDataRadarFarStationById(Long dataId)
    {
        return DataRadarFarStation .selectDataRadarFarStationById(dataId);
    }

mapper
 
    public DataGts2Query selectDataRadarFarStationById(Long dataId);

sql


        select * from 
        where data_id = #{dataId}