SpringMVC学习记录（九）----SSM 框架实战 用户信息增删改查

SSM 框架实战—用户信息增删改查

（1）效果展示

（2）pojo层

User 实体类

package com.bit.pojo;

import lombok.AllArgsConstructor;
import lombok.Data;
import lombok.NoArgsConstructor;

@Data
@AllArgsConstructor
@NoArgsConstructor
public class User {
   
    private int id;
    private String username;
    private String password;
}

（3）mapper层

UserMapper接口以及对应的xml文件

UserMapper接口

package com.bit.mapper;

import com.bit.pojo.User;
import org.apache.ibatis.annotations.Param;

import java.util.HashMap;
import java.util.List;

public interface UserMapper {
   

    int insert(User user);

    int delete(@Param("id") int id);

    int update(HashMap<String,Object> map);

    List<User>  selectAll();

    User selectById(int id);

}

UserMapper.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="com.bit.mapper.UserMapper">
    <insert id="insert" parameterType="user">
        insert into users values(#{id},#{username},#{password})
    </insert>

    <delete id="delete">
        delete from users where id=#{id}
    </delete>

    <update id="update">
        update users set username=#{username},password=#{password} where id=#{id}
    </update>

    <select id="selectAll" resultType="user" >
        select * from users;
    </select>

    <select id="selectById" resultType="user" >
        select * from users where id=#{id};
    </select>

</mapper>

（4）service层

UserService接口

package com.bit.service;

import com.bit.pojo.User;

import java.util.List;

public interface UserService {
   

    int addUser(User user);

    int  delteteUser(int id);

    int  updateUser(int id,User user);

    List<User> selectAllUser();

    User selectOne(int id);

}

UserServiceImpl 实现类

package com.bit.service;

import com.bit.mapper.UserMapper;
import com.bit.pojo.