找回密码功能的实现（考虑安全性，加密方面）

/* ------------------------------------------忘记密码，发送邮件------------------------------------------------- */
	//找回密码发送邮件功能
	@RequestMapping(value="getPwd.action")
	public String getPwd(HttpServletRequest request) throws Exception{
		
			User model = userDao.check(request.getParameter("name"));
			
			if(model != null && !model.equals("")){
				//秘钥
				String secretKey = UUID.randomUUID().toString();
				//30分钟后过期
				Timestamp outDate = new Timestamp(System.currentTimeMillis()+30*60*1000);
				//忽略毫秒数
				long date = outDate.getTime()/1000*1000;
				
				String key = model.getName()+"$"+date+"$"+secretKey;
				String digitalSignature = md5.getMD5ofStr(key); //数字签名
				
				String emailTitle = "找回密码";
				String path = request.getContextPath();
				String basePath = request.getScheme()+"://"+request.getServerName()+":"+request.getServerPort()+path+"/";
				String resetPassHref = basePath+"fupdatePwd.action?sid="+digitalSignature+"&name="+model.getName();
				String emailContent = "请勿回复本邮件，点击下面链接，重置密码<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;
				String name = model.getName();
				String to = model.getEmail();
				//发送邮件
				Mail.sendAndCc(to, emailContent);//Mail.java上文已经提到，是用来发送邮件的工具类
				request.setAttribute("message", "提交成功，请注意查看邮箱！");
				return "forward:/getPwd.jsp";
				
			}else{
				request.setAttribute("error", "查无此用户!");
				return "forward:/getPwd.jsp";
			}
				
			
		
	}
	
	//跳转到忘记密码，提交用户界面
	@RequestMapping(value="fgetPwd.action")
	public String fGetPwd(){
		return "forward:/getPwd.jsp";
	}
	
	//跳转到重置密码的页面
	@RequestMapping(value="fupdatePwd.action")
	public String fupdatePwd(HttpServletRequest request) throws Exception{
		String name = request.getParameter("name");
		request.setAttribute("user", userDao.check(name));
		return "forgetPwd";
	}
	
	
	//重置密码
	@RequestMapping(value="updatePwd.action")
	public String updatePwd(HttpServletRequest request) throws Exception{
		User user = new User();
		user.setId(Integer.parseInt(request.getParameter("id")));
		String password = request.getParameter("password");
		user.setPassword(md5.getMD5ofStr(password));//MD5也是一个工具类，其作用是对密码进行加密
		userDao.updatePwd(user);
		return "redirect:index.jsp";
	}