No qualifying bean of type [com.hmc.dao.StudentDao] found for dependency:

帮忙：我这个一直显示
No qualifying bean of type [com.hmc.dao.StudentDao] found for dependency: expected at least 1 bean which qualifies as autowire candidate for this dependency.

注入失败，以下是我的配置环境，请各位麻烦看一下，到底咋回事，三天了，这个一直突破不了，快郁闷死了，网上各种方法都试过了，还是不行
spring配置文件：

<?xml version="1.0" encoding="UTF-8"?>
<beans xmlns="http://www.springframework.org/schema/beans"
       xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
       xmlns:context="http://www.springframework.org/schema/context"
       xmlns:tx="http://www.springframework.org/schema/mvc"
       xsi:schemaLocation="http://www.springframework.org/schema/beans
       http://www.springframework.org/schema/beans/spring-beans.xsd
       http://www.springframework.org/schema/context
       https://www.springframework.org/schema/context/spring-context.xsd http://www.springframework.org/schema/mvc https://www.springframework.org/schema/mvc/spring-mvc.xsd">

    <!--配置spring文件：声明service，dao，utils等工具类对象-->
    <context:property-placeholder location="classpath:conf/jdbc.properties"/>
<!--    <context:component-scan base-package="com.hmc.dao"/>
    <tx:annotation-driven/>-->

    <!--数据库连接池（德鲁伊连接池）-->
    <bean id="dataSource" class="com.alibaba.druid.pool.DruidDataSource">
        <property name="url" value="${jdbc.url}" />
        <property name="username" value="${jdbc.username}" />
        <property name="password" value="${jdbc.password}" />
    </bean>

    <!--SqlSessionFactoryBean创建SqlSessionFactory-->
    <bean id="sqlSessionFactory" class="org.mybatis.spring.SqlSessionFactoryBean">
        <property name="dataSource" ref="dataSource"/>
        <property name="configLocation" value="classpath:conf/mybatis.xml"/>
    </bean>

    <!--声明mybatis的扫描器，创建dao对象-->
    <bean class="org.mybatis.spring.mapper.MapperScannerConfigurer">
        <!--要求映射接口方法名与DAO接口方法名一致-->
        <property name="basePackage" value="com.hmc.dao"/>
        <property name="sqlSessionFactoryBeanName" value="sqlSessionFactory"/>
    </bean>
    
    <!--声明service的注解@Service所在的包名-->
    <context:component-scan base-package="com.hmc.service"/>




</beans>
注释报错：

org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'studentServiceImpl': Injection of autowired dependencies failed; nested exception is org.springframework.beans.factory.BeanCreationException: Could not autowire field: private com.hmc.dao.StudentDao com.hmc.service.impl.StudentServiceImpl.studentDao; nested exception is org.springframework.beans.factory.NoSuchBeanDefinitionException: No qualifying bean of type [com.hmc.dao.StudentDao] found for dependency: expected at least 1 bean which qualifies as autowire candidate for this dependency. Dependency annotations: {@org.springframework.beans.factory.annotation.Autowired(required=true)}
        at org.springframework.beans.factory.annotation.AutowiredAnnotationBeanPostProcessor.postProcessPropertyValues(AutowiredAnnotationBeanPostProcessor.java:334)
        at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.populateBean(AbstractAutowireCapableBeanFactory.java:1202)
        at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.doCreateBean(AbstractAutowireCapableBeanFactory.java:537)
        at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBean(AbstractAutowireCapableBeanFactory.java:476)
        at org.springframework.beans.factory.support.AbstractBeanFactory$1.getObject(AbstractBeanFactory.java:302)
        at org.springframework.beans.factory.support.DefaultSingletonBeanRegistry.getSingleton(DefaultSingletonBeanRegistry.java:230)
        at org.springframework.beans.factory.support.AbstractBeanFactory.doGetBean(AbstractBeanFactory.java:298)
        at org.springframework.beans.factory.support.AbstractBeanFactory.getBean(AbstractBeanFactory.java:193)
        at org.springframework.beans.factory.support.DefaultListableBeanFactory.preInstantiateSingletons(DefaultListableBeanFactory.java:762)
        at org.springframework.context.support.AbstractApplicationContext.finishBeanFactoryInitialization(AbstractApplicationContext.java:757)
        at org.springframework.context.support.AbstractApplicationContext.refresh(AbstractApplicationContext.java:480)
        at org.springframework.web.context.ContextLoader.configureAndRefreshWebApplicationContext(ContextLoader.java:403)
        at org.springframework.web.context.ContextLoader.initWebApplicationContext(ContextLoader.java:306)
        at org.springframework.web.context.ContextLoaderListener.contextInitialized(ContextLoaderListener.java:106)
        at org.apache.catalina.core.StandardContext.listenerStart(StandardContext.java:4686)
        at org.apache.catalina.core.StandardContext.startInternal(StandardContext.java:5147)
        at org.apache.catalina.util.LifecycleBase.start(LifecycleBase.java:183)
        at org.apache.catalina.core.ContainerBase.addChildInternal(ContainerBase.java:717)
        at org.apache.catalina.core.ContainerBase.addChild(ContainerBase.java:690)
        at org.apache.catalina.core.StandardHost.addChild(StandardHost.java:705)
        at org.apache.catalina.startup.HostConfig.manageApp(HostConfig.java:1727)
        at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
        at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
        at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
        at java.lang.reflect.Method.invoke(Method.java:498)
        at org.apache.tomcat.util.modeler.BaseModelMBean.invoke(BaseModelMBean.java:288)
        at com.sun.jmx.interceptor.DefaultMBeanServerInterceptor.invoke(DefaultMBeanServerInterceptor.java:819)
        at com.sun.jmx.mbeanserver.JmxMBeanServer.invoke(JmxMBeanServer.java:801)
        at org.apache.catalina.mbeans.MBeanFactory.createStandardContext(MBeanFactory.java:456)
        at org.apache.catalina.mbeans.MBeanFactory.createStandardContext(MBeanFactory.java:405)
        at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
        at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
        at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
        at java.lang.reflect.Method.invoke(Method.java:498)
        at org.apache.tomcat.util.modeler.BaseModelMBean.invoke(BaseModelMBean.java:288)
        at com.sun.jmx.interceptor.DefaultMBeanServerInterceptor.invoke(DefaultMBeanServerInterceptor.java:819)
        at com.sun.jmx.mbeanserver.JmxMBeanServer.invoke(JmxMBeanServer.java:801)
        at com.sun.jmx.remote.security.MBeanServerAccessController.invoke(MBeanServerAccessController.java:468)
        at javax.management.remote.rmi.RMIConnectionImpl.doOperation(RMIConnectionImpl.java:1468)
        at javax.management.remote.rmi.RMIConnectionImpl.access$300(RMIConnectionImpl.java:76)
        at javax.management.remote.rmi.RMIConnectionImpl$PrivilegedOperation.run(RMIConnectionImpl.java:1309)
        at java.security.AccessController.doPrivileged(Native Method)
        at javax.management.remote.rmi.RMIConnectionImpl.doPrivilegedOperation(RMIConnectionImpl.java:1408)
        at javax.management.remote.rmi.RMIConnectionImpl.invoke(RMIConnectionImpl.java:829)
        at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
        at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
        at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
        at java.lang.reflect.Method.invoke(Method.java:498)
        at sun.rmi.server.UnicastServerRef.dispatch(UnicastServerRef.java:346)
        at sun.rmi.transport.Transport$1.run(Transport.java:200)
        at sun.rmi.transport.Transport$1.run(Transport.java:197)
        at java.security.AccessController.doPrivileged(Native Method)
        at sun.rmi.transport.Transport.serviceCall(Transport.java:196)
        at sun.rmi.transport.tcp.TCPTransport.handleMessages(TCPTransport.java:568)
        at sun.rmi.transport.tcp.TCPTransport$ConnectionHandler.run0(TCPTransport.java:826)
        at sun.rmi.transport.tcp.TCPTransport$ConnectionHandler.lambda$run$0(TCPTransport.java:683)
        at java.security.AccessController.doPrivileged(Native Method)
        at sun.rmi.transport.tcp.TCPTransport$ConnectionHandler.run(TCPTransport.java:682)
        at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1142)
        at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:617)
        at java.lang.Thread.run(Thread.java:745)
    Caused by: org.springframework.beans.factory.BeanCreationException: Could not autowire field: private com.hmc.dao.StudentDao com.hmc.service.impl.StudentServiceImpl.studentDao; nested exception is org.springframework.beans.factory.NoSuchBeanDefinitionException: No qualifying bean of type [com.hmc.dao.StudentDao] found for dependency: expected at least 1 bean which qualifies as autowire candidate for this dependency. Dependency annotations: {@org.springframework.beans.factory.annotation.Autowired(required=true)}
        at org.springframework.beans.factory.annotation.AutowiredAnnotationBeanPostProcessor$AutowiredFieldElement.inject(AutowiredAnnotationBeanPostProcessor.java:558)
        at org.springframework.beans.factory.annotation.InjectionMetadata.inject(InjectionMetadata.java:87)
        at org.springframework.beans.factory.annotation.AutowiredAnnotationBeanPostProcessor.postProcessPropertyValues(AutowiredAnnotationBeanPostProcessor.java:331)
        ... 60 more
    Caused by: org.springframework.beans.factory.NoSuchBeanDefinitionException: No qualifying bean of type [com.hmc.dao.StudentDao] found for dependency: expected at least 1 bean which qualifies as autowire candidate for this dependency. Dependency annotations: {@org.springframework.beans.factory.annotation.Autowired(required=true)}
        at org.springframework.beans.factory.support.DefaultListableBeanFactory.raiseNoSuchBeanDefinitionException(DefaultListableBeanFactory.java:1308)
        at org.springframework.beans.factory.support.DefaultListableBeanFactory.doResolveDependency(DefaultListableBeanFactory.java:1054)
        at org.springframework.beans.factory.support.DefaultListableBeanFactory.resolveDependency(DefaultListableBeanFactory.java:949)
        at org.springframework.beans.factory.annotation.AutowiredAnnotationBeanPostProcessor$AutowiredFieldElement.inject(AutowiredAnnotationBeanPostProcessor.java:530)
        ... 62 more
26-Nov-2021 11:14:43.065 信息 [RMI TCP Connection(3)-127.0.0.1] org.apache.catalina.core.ApplicationContext.log Log4jServletContextListener ensuring that Log4j starts up properly.
26-Nov-2021 11:14:43.069 信息 [RMI TCP Connection(3)-127.0.0.1] org.apache.catalina.core.ApplicationContext.log Log4jServletContextListener ensuring that Log4j shuts down properly.
26-Nov-2021 11:14:43.069 信息 [RMI TCP Connection(3)-127.0.0.1] org.apache.catalina.core.ApplicationContext.log Closing Spring root WebApplicationContext

没太理解为什么要注入dao层

你不只有个全局配置文件吧