仿牛客网社区项目（七）登录和退出

开发登录功能

• 访问登录页面
  • 点击顶部区域内的链接，打开登录页面。
• 登录
  • 验证账号、密码、验证码。
  • 成功时，生成登录凭证，发放给客户端。
  • 失败时，跳转回登录页。
• 退出
  • 将登录凭证修改为失效状态。
  • 跳转至网站首页。

一、登录#

①首先将登录凭证封装成一个类LoginTicket

public class LoginTicket {
    private int id;
    private int userId;
    private String ticket;
    private int status;
    private Date expired;
    ...
 }

②在DAO包下新建LoginTicketMapper接口，定义与数据库的交互

@Mapper
public interface LoginTicketMapper {
    @Insert({
            "insert into login_ticket(user_id,ticket,status,expired) ",
            "values(#{userId},#{ticket},#{status},#{expired})"
    })
    @Options(useGeneratedKeys = true, keyProperty = "id")
    int insertLoginTicket(LoginTicket loginTicket);
    @Select({
            "select id,user_id,ticket,status,expired ",
            "from login_ticket where ticket=#{ticket}"
    })
    LoginTicket selectByTicket(String ticket);
    @Update({
            "update login_ticket set status=#{status} where ticket=#{ticket}"
    })
    int updateStatus(String ticket, int status);
}

③在测试类中进行测试，LoginTicketMapper类中定义的两个方法

@Test
    public void testInsertLoginTicket(){
        LoginTicket loginTicket = new LoginTicket();
        loginTicket.setUserId(101);
        loginTicket.setTicket("abc");
        loginTicket.setStatus(0);
        loginTicket.setExpired(new Date(System.currentTimeMillis() + 1000 * 60 * 10));
        loginTicketMapper.insertLoginTicket(loginTicket);
    }
    @Test
    public void testSelectLoginTicket(){
        LoginTicket loginTicket = loginTicketMapper.selectByTicket("abc");
        System.out.println(loginTicket);
        loginTicketMapper.updateStatus("abc",1);
        loginTicket = loginTicketMapper.selectByTicket("abc");
        System.out.println(loginTicket);
    }

④在服务层编写登录逻辑，包括实现账号密码的验证功能，生成登录凭证。这一层输入的输入值有账号，密码，有效期。

public Map<String,Object> login(String username, String password, int expiredSeconds){
        Map<String, Object> map = new HashMap<>();
        //空值处理
        if(StringUtils.isBlank(username)){
            map.put("usernameMsg","账号不能为空");
            return map;
        }
        if(StringUtils.isBlank(password)){
            map.put("passwordMsg","密码不能为空");
            return map;
        }
        //验证账号
        User user = userMapper.selectByName(username);
        if(user == null){
            map.put("usernameMsg","该账号不存在");
            return map;
        }
        if(user.getStatus() == 0){
            map.put("usernameMsg","该账号未激活");
            return map;
        }
        //验证密码
        password = CommunityUtil.md5(password + user.getSalt());
        if(!user.getPassword().equals(password)){
            map.put("passwordMsg","密码不正确");
            return map;
        }
        //生成登录凭证
        LoginTicket loginTicket = new LoginTicket();
        loginTicket.setUserId(user.getId());
        loginTicket.setTicket(CommunityUtil.generateUUID());
        loginTicket.setStatus(0);
        loginTicket.setExpired(new Date(System.currentTimeMillis() + expiredSeconds * 1000));
        loginTicketMapper.insertLoginTicket(loginTicket);
        map.put("ticket",loginTicket.getTicket());
        return map;
    }

⑤编写表现层（Controller）层的逻辑，（思维误区：数据都是从前端.html文件中读入的，而不是controller层）
成功时给客户端发送一个cookie，失败时跳转回登录页

@RequestMapping(path = "/login", method = RequestMethod.POST)
    public String login(String username,String password,String code,boolean rememberme,
                        Model model,HttpSession session, HttpServletResponse response){
        //检查验证码
        String kaptcha = (String) session.getAttribute("kaptcha");
        if(StringUtils.isBlank(kaptcha) ||StringUtils.isBlank(code) ||!kaptcha.equalsIgnoreCase(code) ){
            model.addAttribute("codeMsg","验证码不正确");
            return "/site/login";
        }
        //检查账号密码
        int expiredSeconds = rememberme? REMEMBER_EXPIRED_SECONDS : DEFAULT_EXPIRED_SECONDS;
        Map<String,Object> map = userService.login(username,password,expiredSeconds);
        if(map.containsKey("ticket")){
            Cookie cookie = new Cookie("ticket",map.get("ticket").toString());
            cookie.setPath(contextPath);
            cookie.setMaxAge(expiredSeconds);
            response.addCookie(cookie);
            return "redirect:/index";
        }else{
            model.addAttribute("usernameMsg",map.get("usernameMsg"));
            model.addAttribute("passwordMsg",map.get("passwordMsg"));
            return "/site/login";
        }
    }

⑥配置好对应的.html文件

二、退出#

⑦退出功能比较简单，只需将登录凭证修改为失效状态，LoginTicketMapper接口中已完成了和更新状态功能和数据库的交互，因此只需完成服务层和表现层的编写即可
服务层代码：

public void logout(String ticket){
        loginTicketMapper.updateStatus(ticket,1);
}

表现层代码：

@RequestMapping(path = "/logout", method = RequestMethod.GET)
    public String logout(@CookieValue("ticket") String ticket){
        userService.logout(ticket);
        return "redirect:/login";
    }

完成对应的.html文件的配置