利用SpringBoot整合mybatis

代码地址：https://gitee.com/jkangle/springboot-exercise.git

1.构建SpringBoot项目

• 注意版本不能太高
• 版本太高会出现问题
• 整体的项目结构如图
  

2.导入Mybatis依赖

<!-- https://mvnrepository.com/artifact/org.mybatis/mybatis -->
        <dependency>
            <groupId>org.mybatis</groupId>
            <artifactId>mybatis</artifactId>
            <version>3.5.11</version>
        </dependency>

3.写domain层

这一层主要是建立和数据库的映射

package com.jkk.springboot_mybatis.domain;
import lombok.AllArgsConstructor;
import lombok.Data;
import lombok.NoArgsConstructor;
import lombok.ToString;

import java.io.Serializable;
/**
 * @TableName users
 * @author jkk
*/
@NoArgsConstructor
@AllArgsConstructor
@ToString
@Data
public class Users implements Serializable {
    private String username;
    private String password;
    private String idNumber;
    private String phoneNumber;
    private String gender;
    private String dataStatus;
    private static final long serialVersionUID = 1L;
}

4.写mapper层

mapper层主要是对数据库的操作接口

package com.jkk.springboot_mybatis.mapper;

import com.jkk.springboot_mybatis.domain.Users;
import org.springframework.stereotype.Repository;

import java.util.List;

/**
 * @author jkk
 */
@Repository
public interface UserMapper {
    /**
     * 增加用户
     * @param users
     * @return
     */
    int adduser(Users users);

    /**
     * 删除用户
     * @param username
     * @return
     */
    int deleteUser(String username);

    /**
     * 更新用户
     * @param users
     * @return
     */
    int updateUser(Users users);

    /**
     * 查询单个用户
     * @param username
     * @return
     */
    Users getByUserName(String username);

    /**
     * 查询所有的用户
     * @return
     */
    List<Users> getAllUser();
}

mapper层的具体的实现有两种的方式来书写，通过 注解配置，或者通过xml文件配置

<?xml version="1.0" encoding="utf-8" ?>
<!DOCTYPE mapper PUBLIC "-//mybatis.org//DTO Mapper 3.0//EN"
        "http://mybatis.org/dtd/mybatis-3-mapper.dtd">
<mapper namespace="com.jkk.springboot_mybatis.mapper.UserMapper">
    <select id="getByUserName" resultType="Users">
        select * from users where username = #{username}
    </select>
    <select id="getAllUser" resultType="Users">
        select * from users
    </select>
    <insert id="adduser" parameterType="Users">
        insert into users(username,password,id_number,phone_number,gender,data_status)values (#{username},#{password},#{idNumber},#{phoneNumber},#{gender},#{dataStatus})
    </insert>
    <update id="deleteUser" parameterType="String">
        delete
        from users
        where username = #{username};
    </update>
    <update id="updateUser" parameterType="Users">
        update users set password = #{password} where username=#{username}
    </update>

</mapper>

5.写service层

具体的业务层

//接口
package com.jkk.springboot_mybatis.service;

import com.github.pagehelper.PageInfo;
import com.jkk.springboot_mybatis.domain.Users;

import java.util.List;

/**
 * @author jkk
 */
public interface UserService {
    /**
     * 增加用户
     * @param users
     * @return
     */
    int adduser(Users users);

    /**
     * 删除用户
     * @param username
     * @return
     */
    int deleteUser(String username);

    /**
     * 更新用户
     * @param users
     * @return
     */
    int updateUser(Users users);

    /**
     * 查询单个用户
     * @param username
     * @return
     */
    Users getByUserName(String username);

    /**
     * 查询所有的用户
     * @return
     */
    List<Users> getAllUser();

    /**
     * 分页查询
     * @param pageNum
     * @param pageSize
     * @return
     */
    public PageInfo<Users> findAll(int pageNum,int pageSize);
}

//具体的实现类
package com.jkk.springboot_mybatis.service.impl;

import com.github.pagehelper.PageHelper;
import com.github.pagehelper.PageInfo;
import com.github.pagehelper.page.PageMethod;
import com.jkk.springboot_mybatis.domain.Users;
import com.jkk.springboot_mybatis.mapper.UserMapper;
import com.jkk.springboot_mybatis.service.UserService;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Service;

import java.util.List;

/**
 * @author jkk
 */
@Service
public class UserServiceImpl implements UserService {
    @Autowired
    private UserMapper userMapper;
    @Override
    public int adduser(Users users) {
        return userMapper.adduser(users);
    }

    @Override
    public int deleteUser(String username) {
        return userMapper.deleteUser(username);
    }

    @Override
    public int updateUser(Users users) {
        return userMapper.updateUser(users);
    }

    @Override
    public Users getByUserName(String username) {
        return userMapper.getByUserName(username);
    }

    @Override
    public List<Users> getAllUser() {
        return userMapper.getAllUser();
    }

    @Override
    public PageInfo<Users> findAll(int pageNum, int pageSize) {
        PageMethod.startPage(pageNum, pageSize);
        List<Users> allUser = userMapper.getAllUser();
        return new PageInfo<>(allUser);
    }
}

6.写controller层

package com.jkk.springboot_mybatis.controller;

import com.github.pagehelper.PageHelper;
import com.github.pagehelper.PageInfo;
import com.jkk.springboot_mybatis.domain.Users;
import com.jkk.springboot_mybatis.service.UserService;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.web.bind.annotation.*;

import java.util.List;

/**
 * @author jkk
 */
@RestController
@RequestMapping("/user")
public class MybatisTestController{
    @Autowired
    private UserService userService;

    /**
     * 插入功能
     * @param users
     * @return
     */
    @PostMapping("")
    public int add(@RequestBody Users users){
        return userService.adduser(users);
    }

    /**
     * 查询功能
     * @return
     */
    @GetMapping("/list")
    public List<Users> getAll(){
        return userService.getAllUser();
    }
    @GetMapping("/list1/{pageNum}/{pageSize}")
    public PageInfo getAllUser(@PathVariable("pageNum") int pageNum, @PathVariable("pageSize") int pageSize) {
        return userService.findAll(pageNum, pageSize);
    }

    @DeleteMapping("/{username}")
    public int deleteUser(@PathVariable("username") String username){
        return userService.deleteUser(username);
    }
}

当然还需要配置yml文件

spring:
  datasource:
    driver-class-name: com.mysql.cj.jdbc.Driver
    url: jdbc:mysql://localhost:3306/worktest?characterEncoding=UTF-8
    username: root
    password:
    type: com.alibaba.druid.pool.DruidDataSource
mybatis:
  type-aliases-package: com.jkk.springboot_mybatis.domain
  mapper-locations: classpath:mapper/*.xml
  configuration:
    map-underscore-to-camel-case: true
# 设置日志级别
logging:
  level:
    root: DEBUG
    com.jkk: debug

pagehelper:
  helper-dialect: mysql
  reasonable: true
  support-methods-arguments: true
  params: count=countSql

---

以上就是Springboot整合mybatis的全部过程，可以通过postman或者浏览器测试(只对分页做测试)