1.导入依赖

搭建是Springboot可以看我上一篇  使用maven搭建Springboot

在pom.xml中添加mysql连接需要的依赖

      <dependency>
            <groupId>mysql</groupId>
            <artifactId>mysql-connector-java</artifactId>
            <version>8.0.29</version>
        </dependency>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-jdbc</artifactId>
        </dependency>
        <dependency>
            <groupId>com.baomidou</groupId>
            <artifactId>mybatis-plus-boot-starter</artifactId>
            <version>3.5.1</version>
        </dependency>

添加lombok依赖

<dependency>
            <groupId>org.projectlombok</groupId>
            <artifactId>lombok</artifactId>
            <optional>true</optional>
</dependency>

二、添加数据库配置

在application.yml中进行连接数据库的简单配置

spring:
  datasource:
    driver-class-name: com.mysql.cj.jdbc.Driver
    type: com.zaxxer.hikari.HikariDataSource
    url: jdbc:mysql://localhost:3306/test?useUnicode=true&characterEncoding=utf-8&useSSL=true
    username: root
    password: root

 数据库添加用户表

三、测试

使用mybatis-plus进行映射

1.创建UserDomian 实体类

采用了Lombok简化代码

@Data
@NoArgsConstructor
@AllArgsConstructor
@TableName("user")
public class UserDomian {
    @TableId(value = "id",type = IdType.AUTO)
    private int id;
    @TableField("name")
    private String name;
    @TableField("address")
    private String address;
}

2.在Mapper包下创建UserMapper类

@Repository
public interface UserMapper extends BaseMapper<UserDomian> {

}

3.TestController 添加接口

@RestController
@RequestMapping("/test")
public class TestController {

    @Autowired
    UserMapper userMapper;
    @GetMapping("/hello")
    public String hello() {
        return "Hello World";
    }
    @GetMapping("/getUsers")
    public String getUsers() {
        return userMapper.selectList(null).toString();
    }

}

4.在启动类增加注解

在启动类SbvApplication 增加@MapperScan(“包名”)，包名需要指定到mapper包

@SpringBootApplication
@MapperScan("com.mansai.mapper")
public class SpringStartApplication {

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

启动程序，访问接口 localhost:8081/test/getUsers。