springboot service 用 @Autowired注入 mapper 为null

Service类

@Controller
public class AdminRoleService {
    @Autowired
    AdminRoleMapper adminRoleMapper;

    public AdminRole selectByPrimaryKey(Integer roleId) {
        AdminRole adminRole = adminRoleMapper.selectByPrimaryKey(10001);
        return adminRole;
    }
}

测试调用类

@Resource
AdminRoleService adminRoleService;

@Test
void contextLoads() {
    AdminRole adminRole = adminRoleService.selectByPrimaryKey(10001);
    log.info(adminRole.getTitle());
}

注意：调用有@Autowired的类，不能用new，否则Autowiredl类会出现null，应该用@Resource或@Autowired注入进来

@Resource与@Autowired注解区别

@Autowired 默认byName方式
@Resource 默认byName方式，如果找不到名字，会调用byType方式自动装配

@Autowired 通过 @Qualifier(value = “Address2”) 指定名称
@Resource 通过 @Resource(name = “Address2”) 指定名称

@Resource 比较强大，性能比较差

标签：mapper,selectByPrimaryKey,调用,Resource,springboot,service,Autowired,AdminRole,adm
来源： https://blog.csdn.net/weixin_44371237/article/details/116698721