Spring Boot应用启动失败：解决UnsatisfiedDependencyException与NoSuchBeanDefinitionException

Error starting ApplicationContext. To display the conditions report re-run your application with 'debug' enabled.
2025-06-04 17:55:24 | ERROR | main | org.springframework.boot.SpringApplication | Application run failed
org.springframework.beans.factory.UnsatisfiedDependencyException: Error creating bean with name 'emailServiceImpl': Unsatisfied dependency expressed through field 'baseMapper'; nested exception is org.springframework.beans.factory.NoSuchBeanDefinitionException: No qualifying bean of type 'com.middle.common.mail.mapper.EmailAccountMapper' available: expected at least 1 bean which qualifies as autowire candidate. Dependency annotations: {@org.springframework.beans.factory.annotation.Autowired(required=true)}

@Mapper  // 关键注解
public interface EmailAccountMapper {
    // 方法定义
}

@SpringBootApplication
@MapperScan("com.middle.common.mail.mapper")  // 指定Mapper接口所在的包
public class AdControlApplication {
    public static void main(String[] args) {
        SpringApplication.run(AdControlApplication.class, args);
    }
}

mybatis:
  mapper-locations: classpath:mapper//.xml  # 指定XML映射文件位置
  type-aliases-package: com.middle.common.mail.model  # 实体类包路径

<!-- resources/mapper/EmailAccountMapper.xml -->
<mapper namespace="com.middle.common.mail.mapper.EmailAccountMapper">
    <select id="selectById" resultType="com.middle.common.mail.model.EmailAccount">
        SELECT  FROM email_account WHERE id = #{id}
    </select>
</mapper>

<!-- MyBatis Plus Starter -->
<dependency>
    <groupId>com.baomidou</groupId>
    <artifactId>mybatis-plus-boot-starter</artifactId>
    <version>3.5.6</version>
</dependency>

<!-- 如果使用MyBatis原生 -->
<dependency>
    <groupId>org.mybatis.spring.boot</groupId>
    <artifactId>mybatis-spring-boot-starter</artifactId>
    <version>2.3.2</version>
</dependency>

logging:
  level:
    org.springframework: DEBUG

@SpringBootApplication
public class AdControlApplication {
    public static void main(String[] args) {
        ConfigurableApplicationContext context = SpringApplication.run(AdControlApplication.class, args);
        // 检查Mapper是否被加载
        try {
            EmailAccountMapper mapper = context.getBean(EmailAccountMapper.class);
            System.out.println("Mapper加载成功: " + mapper);
        } catch (Exception e) {
            System.err.println("Mapper未加载: " + e.getMessage());
        }
    }
}

mvn dependency:tree | grep mybatis

src/
├── main/
│   ├── java/
│   │   └── com.middle/
│   │       ├── AdControlApplication.java  # 主启动类
│   │       ├── common/
│   │       │   └── mail/
│   │       │       ├── mapper/  # Mapper接口
│   │       │       ├── model/   # 实体类
│   │       │       └── service/ # Service层
│   ├── resources/
│   │   ├── mapper/  # XML映射文件
│   │   ├── application.yml

@Mapper
public interface EmailAccountMapper extends BaseMapper<EmailAccount> {
    // 无需手动编写CRUD方法
}