@RequestMapping(value = "/user/i_forget_password")
    @ResponseBody
    public Map forgetPass(HttpServletRequest request,String userName){
        Users users = userService.findUserByName(userName);
        Map map = new HashMap<String,String >();
        String msg = "";
        if(users == null){              //用户名不存在
            msg = "用户名不存在,你不会忘记用户名了吧?";
            map.put("msg",msg);
            return map;
        }
        try{
            String secretKey= UUID.randomUUID().toString();  //密钥
            Timestamp outDate = new Timestamp(System.currentTimeMillis()+30*60*1000);//30分钟后过期
            long date = outDate.getTime()/1000*1000;                  //忽略毫秒数
            users.setValidataCode(secretKey);
            users.setRegisterDate(outDate);
            userService.update(users);    //保存到数据库
            String key = users.getUserName()+"$"+date+"$"+secretKey;
            String digitalSignature = MD5.MD5Encode(key);                 //数字签名

            String emailTitle = "有方云密码找回";
            String path = request.getContextPath();
            String basePath = request.getScheme()+"://"+request.getServerName()+":"+request.getServerPort()+path+"/";
            String resetPassHref =  basePath+"user/reset_password?sid="+digitalSignature+"&userName="+users.getUserName();
            String emailContent = "请勿回复本邮件.点击下面的链接,重设密码<br/><a href="+resetPassHref +" target='_BLANK'>点击我重新设置密码</a>" +
                    "<br/>tips:本邮件超过30分钟,链接将会失效，需要重新申请'找回密码'"+key+"\t"+digitalSignature;
            System.out.print(resetPassHref);
            SendMail.getInstatnce().sendHtmlMail(emailTitle,emailContent,users.getEmail());
            msg = "操作成功,已经发送找回密码链接到您邮箱。请在30分钟内重置密码";
            logInfo(request,userName,"申请找回密码");
        }catch (Exception e){
            e.printStackTrace();
            msg="邮箱不存在？未知错误,联系管理员吧。";
        }
        map.put("msg",msg);
        return map;
    }

 @RequestMapping(value = "/user/reset_password",method = RequestMethod.GET)
    public ModelAndView checkResetLink(String sid,String userName){
        ModelAndView model = new ModelAndView("error");
        String msg = "";
        if(sid.equals("") || userName.equals("")){
            msg="链接不完整,请重新生成";
            model.addObject("msg",msg) ;
            logInfo(userName,"找回密码链接失效");
            return model;
        }
        Users users = userService.findUserByName(userName);
        if(users == null){
            msg = "链接错误,无法找到匹配用户,请重新申请找回密码.";
            model.addObject("msg","找回密码链接失效");
            return model;
        }
        Timestamp outDate = users.getRegisterDate();
        if(outDate.getTime() <= System.currentTimeMillis()){         //表示已经过期
            msg = "链接已经过期,"找回密码链接失效");
            return model;
        }
        String key = users.getUserName()+"$"+outDate.getTime()/1000*1000+"$"+users.getValidataCode();          //数字签名
        String digitalSignature = MD5.MD5Encode(key);
        System.out.println(key+"\t"+digitalSignature);
        if(!digitalSignature.equals(sid)) {
            msg = "链接不正确,是否已经过期了?重新申请吧";
            model.addObject("msg","找回密码链接失效");
            return model;
        }
        model.setViewName("user/reset_password");  //返回到修改密码的界面
        model.addObject("userName",userName);
        return model;
    }

      sun.misc.BASE64Encoder enc = new sun.misc.BASE64Encoder();
      mailMessage.setSubject(MimeUtility.encodeText(mailInfo.getSubject(),"UTF-8","B"));      //解决linux邮件title乱码