SpringBoot的helloworld

        org.springframework.boot
        spring-boot-starter-parent
        
        2.4.3
        


    
        UTF-8
        UTF-8
        11
    

        
        
            org.springframework.boot
            spring-boot-starter-web
        
        
        
            mysql
            mysql-connector-java
        
        
            org.springframework.boot
            spring-boot-starter-aop
        
        
        
            com.alibaba
            druid-spring-boot-starter
            1.2.6
        
        
        
            org.mybatis.spring.boot
            mybatis-spring-boot-starter
            2.2.0
        
        
        
            org.springframework.boot
            spring-boot-starter-thymeleaf
            2.5.4
        
        
        
            org.projectlombok
            lombok
            1.18.20
            provided
        

        
            
                org.springframework.boot
                spring-boot-maven-plugin
            
        
    

application.properties

#数据库
spring.datasource.driver-class-name=com.mysql.cj.jdbc.Driver
spring.datasource.password=admin
spring.datasource.username=root
spring.datasource.url=jdbc:mysql://localhost:3306/test?useUnicode=true&characterEncoding=UTF-8&serverTimezone=GMT%2B8

前端thymeleaf页面编写

    
    


    

        

            

                
编号
                
名称
            
            

                

                

            
        
    

后端编写

controller层

@Controller
public class HelloController {
    @Autowired
    private ISchoolService schoolService;

    @RequestMapping("/hello")
    public String hello2(Model model) {
        model.addAttribute("schools",schoolService.query());
        return "/hello";
    }
}

service层

@Service
public class SchoolServiceImpl implements ISchoolService {
    @Autowired
    private SchoolMapper schoolMapper;

    @Override
    public List query() {
        return schoolMapper.selectAll();
    }
}

public interface ISchoolService {
    List query();
}

mapper层

@Repository
public interface SchoolMapper {
    List selectAll();
}

mapper.xml

    
    select * from school
  

实体类

@Getter
@Setter
public class School {
    private Long id;
    private String name;
}

启动类

@SpringBootApplication
@MapperScan(basePackages = "mapper包所在包名")
public class SpringbootDemoApplication {
    public static void main(String[] args) {
        SpringApplication.run(SpringbootDemoApplication.class, args);
    }
}

按照以上编写，可以将MySQL中test库里的school表数据全部打印出来