标签：username 27 java 在线 userMapper user jdbcType tid password

一、项目简介

随着互联网迅速发展，人们的生活已经越来越离不开互联网，人们足不出户就可以工作、学习等。对于在校学生，通过网络教育不仅可以随时进行网络学习，也可以根据学习的情况自我检测，有利于学生高效、快捷地掌握所学的知识。
本系统预设计的基于网络的学生自测系统将实现多种用户（包括学生、教师、管理员）同时访问，学生登录后可以针对课程的每一章节的每一道题目，提交答案；系统会自动按照学生的答案来判断对错，并自动给出成绩。另外，系统还具有添加用户、管理题库、添加试卷、添加习题、修改密码等功能。

简单的一句话，这是一个完整的学生在线考试系统，导入项目和数据库就可以使用；在本考试系统中，管理员、老师、学生三个角色是相当于是三个系统。

二、开发工具和环境

前端：html, css, js, vue等;
后端：java, spring，maven等
数据库：mysql
开发工具： eclipse或idea
更多内容可查看：项目帮

部分核心代码

import org.springframework.stereotype.Service;
import xyz.shiguangliang.mybatis.dao.UserMapper;

import xyz.shiguangliang.mybatis.domain.User;
import xyz.shiguangliang.service.UserService;
import xyz.shiguangliang.util.query.QueryInfo;

import javax.annotation.Resource;
import java.util.Date;
import java.util.List;
import java.util.Objects;

@Service
public class UserServiceImpl implements UserService {
    @Resource
    private UserMapper userMapper;

    //登录
    @Override
    public User login(String username, String password) {
        User user = userMapper.selectLogin(username,password);
        if (user != null) {
            //登录次数加一
            if (user.getIntimes() !=  null) {
                user.setIntimes(user.getIntimes() + 1);
            }else {
                user.setIntimes(1);
            }
            //更新登录时间
            user.setLastlogin(new Date());
            return user;
        }
        return null;
    }

    //注册
    @Override
    public boolean register(User user) {
        int i = 0;
        //检测用户是否存在
        User user1 = userMapper.selectUsername(user.getUsername());
        if (user1 == null) {
            i = userMapper.insert(user);
        }
        return i > 0;
    }

    //用户列表
    @Override
    public QueryInfo getUserList(String query, Integer pagenum,Integer pagesize) {
        QueryInfo queryInfo = new QueryInfo();
        int start;
        int end;
        if (pagenum == null||pagesize == null){
            pagenum =0;
            pagesize = 3;
        }
        start = (pagenum-1)*pagesize;
        end = pagesize;
        int userSize = userMapper.selectUserListLimitSize(query,start,end);
        List<User> users = userMapper.selectUserListLimit(query,start,end);
        queryInfo.setList(users);
        queryInfo.setTotal(userSize);
        return queryInfo;
    }

    //删除用户
    @Override
    public int deleteUser(Integer tid) {
        return userMapper.deleteByPrimaryKey(tid);
    }

    //通过id查找用户
    @Override
    public User findById(Integer tid) {
        return userMapper.selectByPrimaryKey(tid);
    }



    //更新用户
    @Override
    public int updateUser(User user) {
        if (user.getPassword()==null|| Objects.equals(user.getPassword(), "")){
            user.setPassword(userMapper.selectByPrimaryKey(user.getTid()).getPassword());
        }
        return userMapper.updateByPrimaryKey(user);
    }

    //通过用户名查找用户
    @Override
    public User findByUsername(String username) {
        return userMapper.selectUsername(username);
    }

    //获取用户权限
    @Override
    public int getPower(String username) {
        return userMapper.selectUsername(username).getPower();
    }
}

useMapper.xml

<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE mapper PUBLIC "-//mybatis.org//DTD Mapper 3.0//EN" "http://mybatis.org/dtd/mybatis-3-mapper.dtd">
<mapper namespace="xyz.shiguangliang.mybatis.dao.UserMapper">
  <resultMap id="BaseResultMap" type="xyz.shiguangliang.mybatis.domain.User">
    <id column="tid" jdbcType="INTEGER" property="tid" />
    <result column="username" jdbcType="VARCHAR" property="username" />
    <result column="password" jdbcType="VARCHAR" property="password" />
    <result column="teachername" jdbcType="VARCHAR" property="teachername" />
    <result column="dno" jdbcType="INTEGER" property="dno" />
    <result column="power" jdbcType="INTEGER" property="power" />
    <result column="intimes" jdbcType="INTEGER" property="intimes" />
    <result column="lastlogin" jdbcType="TIMESTAMP" property="lastlogin" />
  </resultMap>
  <delete id="deleteByPrimaryKey" parameterType="java.lang.Integer">
    delete from teacher
    where tid = #{tid,jdbcType=INTEGER}
  </delete>
  <insert id="insert" parameterType="xyz.shiguangliang.mybatis.domain.User">
    insert into teacher (tid, username, password, 
      teachername, dno, power, 
      intimes, lastlogin)
    values (#{tid,jdbcType=INTEGER}, #{username,jdbcType=VARCHAR}, #{password,jdbcType=VARCHAR}, 
      #{teachername,jdbcType=VARCHAR}, #{dno,jdbcType=INTEGER}, #{power,jdbcType=INTEGER}, 
      #{intimes,jdbcType=INTEGER}, #{lastlogin,jdbcType=TIMESTAMP})
  </insert>
  <update id="updateByPrimaryKey" parameterType="xyz.shiguangliang.mybatis.domain.User">
    update teacher
    set username = #{username,jdbcType=VARCHAR},
      password = #{password,jdbcType=VARCHAR},
      teachername = #{teachername,jdbcType=VARCHAR},
      dno = #{dno,jdbcType=INTEGER},
      power = #{power,jdbcType=INTEGER},
      intimes = #{intimes,jdbcType=INTEGER},
      lastlogin = #{lastlogin,jdbcType=TIMESTAMP}
    where tid = #{tid,jdbcType=INTEGER}
  </update>
  <select id="selectByPrimaryKey" parameterType="java.lang.Integer" resultMap="BaseResultMap">
    select tid, username, password, teachername, dno, power, intimes, lastlogin
    from teacher
    where tid = #{tid,jdbcType=INTEGER}
  </select>
  <select id="selectAll" resultMap="BaseResultMap">
    select tid, username, password, teachername, dno, power, intimes, lastlogin
    from teacher
  </select>
    <select id="selectLogin" resultType="xyz.shiguangliang.mybatis.domain.User">
        select tid, username, password, teachername, dno, power, intimes, lastlogin
        from teacher
        where username = #{username} and password = #{password}
    </select>
  <select id="selectUsername" resultType="xyz.shiguangliang.mybatis.domain.User">
    select tid, username, password, teachername, dno, power, intimes, lastlogin
        from teacher
        where username = #{username}
  </select>
  <select id="selectUserListLimit" resultType="xyz.shiguangliang.mybatis.domain.User">
    select tid, username, password, teachername, dno, power, intimes, lastlogin
    from teacher
    where
    /*条件判断*/
    <if test="#{query} != null and #{query} != ''">
      /*模糊查询*/
      <bind name="query2" value="'%' + query + '%'"/>
      username like #{query2}
    </if>
    LIMIT #{start},#{end}
  </select>
  <select id="selectUserListLimitSize" resultType="java.lang.Integer">
    select count(*)
    from teacher
    where
    /*条件判断*/
    <if test="#{query} != null and #{query} != ''">
      /*模糊查询*/
      <bind name="query2" value="'%' + query + '%'"/>
      username like #{query2}
    </if>
  </select>
</mapper>