配置文件形式

在这里插入图片描述

pom.xml

<?xml version="1.0" encoding="UTF-8"?>
<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 https://maven.apache.org/xsd/maven-4.0.0.xsd">
    <modelVersion>4.0.0</modelVersion>
    <parent>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter-parent</artifactId>
        <version>2.4.4</version>
        <relativePath/> <!-- lookup parent from repository -->
    </parent>
    <groupId>com.keafmd</groupId>
    <artifactId>spring-boot-09-mybatis</artifactId>
    <version>0.0.1-SNAPSHOT</version>
    <name>spring-boot-09-mybatis</name>
    <description>Demo project for Spring Boot</description>
    <properties>
        <java.version>1.8</java.version>
    </properties>
    <dependencies>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-jdbc</artifactId>
        </dependency>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-web</artifactId>
        </dependency>
        <dependency>
            <groupId>org.mybatis.spring.boot</groupId>
            <artifactId>mybatis-spring-boot-starter</artifactId>
            <version>1.3.2</version>
        </dependency>
        <dependency>
            <groupId>mysql</groupId>
            <artifactId>mysql-connector-java</artifactId>
            <scope>runtime</scope>
        </dependency>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-test</artifactId>
            <scope>test</scope>
        </dependency>
    </dependencies>
    <build>
        <plugins>
            <plugin>
                <groupId>org.springframework.boot</groupId>
                <artifactId>spring-boot-maven-plugin</artifactId>
            </plugin>
        </plugins>
    </build>
</project>

配置数据源

在yml文件中配置数据源。

application.yml：

server:
  port: 80
# 配置数据源
spring:
  datasource:
    url: jdbc:mysql://127.0.0.1:3306/ssm-java1?useSSL=false
    driver-class-name: com.mysql.cj.jdbc.Driver
    username: root
    password: 18044229
# 整合mybatis
mybatis:
  # typeAliasesPackage: com.neuedu.entity
  mapper-locations: classpath*:com/neuedu/boot/mapper/*.xml

UserMapper.xml

这里注意!!!:一定是和UserMapper相同的目录，是个三级目录，创建时仿照这样创建com/keafm/mapper(正确的) 别这样com.keafam.mapper(错误的)，这样错误的创建的话，是个一级目录，不是三级的，后面运行的时候可能会提示找不到Mapper。

<?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.keafmd.mapper.UserMapper">
    <select id="list" resultType="map">
        select * from user
    </select>
</mapper>

UserMapper

package com.keafmd.mapper;
import org.apache.ibatis.annotations.Mapper;
import java.util.List;
/** * Keafmd * * @ClassName: UserMapper * @Description: * @author: 牛哄哄的柯南 * @Date: 2021-04-08 16:09 * @Blog: https://keafmd.blog.csdn.net/ */
public interface UserMapper { 
    List list();
}

配置springboot整合mybatis

在application.yml中配置：

# 整合mybatis
mybatis:
  # typeAliasesPackage: com.neuedu.entity
  mapper-locations: classpath*:com/neuedu/boot/mapper/*.xml

在运行类上添加@MapperScan注解

SpringBoot09MybatisApplication：

package com.keafmd;
import org.mybatis.spring.annotation.MapperScan;
import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;
@SpringBootApplication
@MapperScan("com.keafmd.mapper")
public class SpringBoot09MybatisApplication { 
    public static void main(String[] args) { 
        SpringApplication.run(SpringBoot09MybatisApplication.class, args);
    }
}

测试类

UserMapperTest ：

package com.keafmd.mapper;
import com.keafmd.SpringBoot09MybatisApplication;
import org.junit.jupiter.api.Test;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.boot.test.context.SpringBootTest;
import java.util.List;
import static org.junit.jupiter.api.Assertions.*;
@SpringBootTest(classes = SpringBoot09MybatisApplication.class)
class UserMapperTest { 
    @Autowired
    UserMapper userMapper;
    @Test
    void list(){ 
        List list = userMapper.list();
        for (Object o : list) { 
            System.out.println(o);
        }
    }
}