springboot整合mybatisplus jar

// SpringBoot整合MybatisPlus Jar
// 1. 首先在pom.xml文件中添加MybatisPlus的依赖
<dependency>
    <groupId>com.baomidou</groupId>
    <artifactId>mybatis-plus-boot-starter</artifactId>
    <version>3.4.3</version>
</dependency>

// 2. 在application.properties或application.yml中配置数据源信息
spring.datasource.url=jdbc:mysql://localhost:3306/db_example
spring.datasource.username=springuser
spring.datasource.password=ThePassword
spring.datasource.driver-class-name=com.mysql.cj.jdbc.Driver

// 3. 创建实体类和Mapper接口，使用MybatisPlus的注解进行配置
import com.baomidou.mybatisplus.annotation.TableName;
import com.baomidou.mybatisplus.core.mapper.BaseMapper;
import org.apache.ibatis.annotations.Mapper;

@Mapper
public interface UserMapper extends BaseMapper<User> {
}

@TableName("user")
public class User {
    private Long id;
    private String name;
    // 省略getter和setter
}

// 4. 编写Service层和Controller层，调用Mapper接口进行数据库操作
@Service
public class UserService {
    @Autowired
    private UserMapper userMapper;

    public User getUserById(Long id) {
        return userMapper.selectById(id);
    }
}

@RestController
public class UserController {
    @Autowired
    private UserService userService;

    @GetMapping("/user/{id}")
    public User getUser(@PathVariable Long id) {
        return userService.getUserById(id);
    }
}