@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",msg) ;
      logInfo(userName,"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,请重新申请找回密码.";
      model.addObject("msg",msg) ;
      logInfo(userName,"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",msg) ;
      logInfo(userName,"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;
  }