在SpringBoot中整合Mybatis框架

1.导入依赖:

<dependencies>
        <dependency>
            <groupId>org.mybatis.spring.boot</groupId>
            <artifactId>mybatis-spring-boot-starter</artifactId>
            <version>3.0.4</version>
        </dependency>
<!--        mysql驱动包     -->
        <dependency>
            <groupId>com.mysql</groupId>
            <artifactId>mysql-connector-j</artifactId>
            <scope>runtime</scope>
        </dependency>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-test</artifactId>
            <scope>test</scope>
        </dependency>
<!--        单元测试-->
        <dependency>
            <groupId>org.mybatis.spring.boot</groupId>
            <artifactId>mybatis-spring-boot-starter-test</artifactId>
            <version>3.0.4</version>
            <scope>test</scope>
        </dependency>
        <dependency>
            <groupId>org.projectlombok</groupId>
            <artifactId>lombok</artifactId>
        </dependency>
    </dependencies>

2.配置SpringBoot的配置文件:

#驱动类名称
spring.datasource.driver-class-name=com.mysql.cj.jdbc.Driver
#数据库连接的url
spring.datasource.url=jdbc:mysql://localhost:3306/mydb?useSSL=false
#连接数据库的用户名
spring.datasource.username=root
#连接数据库的密码
spring.datasource.password=123456

3.编写实体类:

package com.example.bean;

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

import java.sql.Struct;
@Data
@AllArgsConstructor
@NoArgsConstructor
public class User {
    private Integer id;
    private String name;
    private Short age;
    private Short gender;
    private String phone;
}

4.编写mapper层(这里以注解的形式注入):

package com.example.mapper;

import com.example.bean.User;
import org.apache.ibatis.annotations.Mapper;
import org.apache.ibatis.annotations.Select;

import java.util.List;

//在运行时，会自动生成实现类的对象（代理对象，并将对象交给IOC容器）
@Mapper
public interface UserMapper {
    //拆线呢全部用户信息
    @Select("select * from user")
    public List<User> list();
}

5.在测试类中进行测试:

package com.example;

import com.example.bean.User;
import com.example.mapper.UserMapper;
import org.junit.jupiter.api.Test;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.boot.test.context.SpringBootTest;

import java.util.List;

@SpringBootTest
class Demo1ApplicationTests {
    @Autowired
    private UserMapper userMapper;

    @Test
    public void test01(){
        List<User> list = userMapper.list();
        list.forEach(System.out::println);

    }

}