博客

场景：根据页面传入的字段，获取所对应的某个实体类的属性值

//利用反射获取
    public String getByAttributeName(BcChannelInfo bcChannelInfo, String attributeName) {
        for (Field field : bcChannelInfo.getClass().getDeclaredFields()) {
            field.setAccessible(true);
            try {
                if (attributeName.toLowerCase().equals(field.getName().toLowerCase())) {
                    return new String(field.get(bcChannelInfo).toString());
                }
            } catch (Exception e) {
                e.printStackTrace();
                return null;
            }
        }
        return null;
    }

下面贴上完整代码

controller：

@RequestMapping("/getUpLoadFile")
    public void getUpLoadFile(HttpServletRequest req, HttpServletResponse resp) {
        OutputStream os = null;
        FileInputStream in = null;
        try {
            String fileType = req.getParameter("fileType");
            String channelId = req.getParameter("channelId");
            //fileType:cardFrontPath、cardEndPath、bankCardPath
            if (StringUtils.isEmpty(fileType)) {
                return;
            }
            //获取已上传文件对应路径  获取对应的属性
            String fileName = bcChannelInfoService.getUpLoadFile(fileType, channelId);

            resp.setHeader("Pragma", "No-cache");
            resp.setHeader("Cache-Control", "No-cache");
            resp.setDateHeader("Expires", 0);
            String format = fileName.substring(fileName.lastIndexOf(".") + 1);
            resp.setHeader("Content-Type", format);

            os = resp.getOutputStream();
            in = new FileInputStream(fileName);
            byte[] bytes = new byte[1024];
            int len = -1;
            while ((len = in.read(bytes)) > 0) {
                os.write(bytes, 0, len);
                os.flush();
            }
        } catch (
                IOException e) {
            log.error("图片信息读取异常：", e);
        } finally {
            try {
                if (in != null) {
                    in.close();
                }
                if (os != null) {
                    os.close();
                }
            } catch (Exception e) {
                log.error("关闭数据流异常:", e);
            }
        }
    }

service：

   /**
     * 获取认证信息
     */
    public String getUpLoadFile(String fileType, String channelId);

serviceimpl：

    /**
     * 获取上传的文件
     */
    @Override
    public String getUpLoadFile(String fileType, String channelId) {
        QueryWrapper<BcChannelInfo> queryWrapper = new QueryWrapper<BcChannelInfo>();
        //根据channelId查询渠道商信息
        queryWrapper.eq("CHANNEL_ID", channelId);
        BcChannelInfo bcChannelInfo = bcChannelInfoMapper.selectOne(queryWrapper);
        String fileName = "";
        if (bcChannelInfo != null && StringUtils.isNotEmpty(fileType)) {
            fileName = getByAttributeName(bcChannelInfo, fileType);
            if (log.isDebugEnabled()) {
                log.debug("获取文件路径信息：" + fileName);
            }
        }
        return fileName;
    }

   public String getByAttributeName(BcChannelInfo bcChannelInfo, String attributeName) {
        for (Field field : bcChannelInfo.getClass().getDeclaredFields()) {
            field.setAccessible(true);
            try {
                if (attributeName.toLowerCase().equals(field.getName().toLowerCase())) {
                    return new String(field.get(bcChannelInfo).toString());
                }
            } catch (Exception e) {
                e.printStackTrace();
                return null;
            }
        }
        return null;
    }