牛客项目（开发登录、退出功能）

需要完成的功能如下

• 登录
• • 验证账号、密码、验证码
  • 生成登录凭证
  • 跳转到登录页
• 退出
• • 将登录凭证修改为失效状态
  • 跳转至网站首页

先把数据存到mysql中，其中ticket是表示唯一的凭证，先写数据访问层，再写业务层，最后写表现层。

1. 写实体类，实现对表的封装，实现增删改查。

package com.newcoder.community.entity;

import java.util.Date;

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

    public int getId() {
        return id;
    }

    public void setId(int id) {
        this.id = id;
    }

    public int getUserId() {
        return userId;
    }

    public void setUserId(int userId) {
        this.userId = userId;
    }

    public String getTicket() {
        return ticket;
    }

    public void setTicket(String ticket) {
        this.ticket = ticket;
    }

    public int getStatus() {
        return status;
    }

    public void setStatus(int status) {
        this.status = status;
    }

    public Date getExpired() {
        return expired;
    }

    public void setExpired(Date expired) {
        this.expired = expired;
    }

    @Override
    public String toString() {
        return "LoginTicket{" +
                "id=" + id +
                ", userId=" + userId +
                ", ticket='" + ticket + ''' +
                ", status=" + status +
                ", expired=" + expired +
                '}';
    }
}

2.接口，三个方法，通过注解加上sql语句。

package com.newcoder.community.dao;

import com.newcoder.community.entity.LoginTicket;
import org.apache.ibatis.annotations.*;

@Mapper
public interface LoginTicketMapper {
//   返回的是行数
    @Insert({
            "insert into login_ticket(user_id,ticket,status,expired) ",
            "values(#{userId},#{ticket},#{status},#{expired}) "
    })
    @Options(useGeneratedKeys = true,keyProperty = "id")
    int insertLoginTicket(LoginTicket loginTicket);
    //    查询方法，整个表是围绕ticket进行的
//    唯一的标识，利用这个标识进行查表
    @Select({
            "select id,user_id,ticket,status,expired ",
            "from login_ticket where ticket =#{ticket} "
    })
    LoginTicket selectByTicket(String ticket);
//    修改凭证的状态，如果是退出，则进行更改
    @Update({
//            动态的sql
            ""
    })
    int updateStatus(String ticket,int status);
}

3. 测试

  @Autowired
    private LoginTicketMapper loginTicketMapper;
    @Test
    public void testInsertLoginTick(){
        LoginTicket loginTicket = new LoginTicket();
        loginTicket.setId(101);
        loginTicket.setTicket("abc");
        loginTicket.setStatus(0);
        loginTicket.setExpired(new Date(System.currentTimeMillis()+1000*60*18));
        loginTicketMapper.insertLoginTicket(loginTicket);
    }

测试结果显示成功插入信息。更新的逻辑也是没有问题的。
服务层直接加到userService`

@Autowired
    private LoginTicketMapper loginTicketMapper;
//    登录的时候有多个情况失败
    public Map login(String username,String password,int expiredSeconds){
        Map 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;
        }
//        判断状态对不对
        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!");
        }
//        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;
    }