添加mysql依赖项

<dependency>
   <groupId>org.mybatis.spring.boot</groupId>
   <artifactId>mybatis-spring-boot-starter</artifactId>
</dependency>

database.properties 配置

添加mysql连接信息

spring.datasource.url=jdbc:mysql://localhost:3306/springboot
spring.datasource.username=root
spring.datasource.password=123456
spring.datasource.driver-class-name=com.mysql.jdbc.Driver
spring.datasource.max-idle=10
spring.datasource.max-wait=10000
spring.datasource.min-idle=5
spring.datasource.initial-size=5

注意：spring boot会默认加载org.springframework.boot.autoconfigure.jdbc.DataSourceAutoConfiguration类使用了@Configuration注解向spring注入了dataSource bean,因为工程中没有关于dataSource相关的配置信息，当spring创建dataSource bean因缺少相关的信息就会报错

因此我们需要在Application类上面增加注解   @EnableAutoConfiguration(exclude={DataSourceAutoConfiguration.class})

package com.example.demo;

import org.springframework.boot.SpringApplication;

import org.springframework.boot.autoconfigure.EnableAutoConfiguration;
import org.springframework.boot.autoconfigure.SpringBootApplication;
import org.springframework.boot.autoconfigure.jdbc.DataSourceAutoConfiguration;

@EnableAutoConfiguration(exclude={DataSourceAutoConfiguration.class})
@SpringBootApplication
public class SpringbootApplication {

public static void main(String[] args) {
SpringApplication.run(SpringbootApplication.class, args);
}

}