Dependency annotations: {@org.springframework.beans.factory.annotation.Autowired(required=true)} 报错

川长思鸟来 2022-05-19 00:11 435阅读 0赞

核心错误提示：Dependency annotations: \{@org.springframework.beans.factory.annotation.Autowired(required=true)\}

项目环境描述：

以spring + spring mvc + MyBatis搭建环境

本来写法，如下所示：

配置注解扫描一：

<context:component-scan base-package="com.lzc.web.*">
 
 <context:include-filter type="annotation" expression="org.springframework.stereotype.Controller"/>
 </context:component-scan>

以上配置信息，写在spring-orm.xml配置文件下。

配置注解扫描二：

<context:component-scan base-package="com.lzc.server.*">
 	
 	<context:include-filter type="annotation" expression="org.springframework.stereotype.Service"/>
 </context:component-scan>

以上配置信息，写在spring-mvc.xml配置文件下。

这样写，本来的设想为（分布式扫描）：

配置一：只扫描com/lzc/server包下的所有被org.springframework.stereotype.Service注解所修饰的子类

配置二：只扫描com/lzc/web包下的所有被org.springframework.stereotype.Controller注解所修饰的子类

后来项目测试时，发现以下问题：

配置一引起的错误：

错误信息：

控制台报错信息：

<table> 
 <tbody> 
 <tr> 
 <td> org.springframework.beans.factory.UnsatisfiedDependencyException:&nbsp;Error&nbsp;creating&nbsp;bean&nbsp;with&nbsp;name&nbsp;'empWeb':&nbsp;Unsatisfied&nbsp;dependency&nbsp;expressed&nbsp;through&nbsp;field&nbsp;'ser';&nbsp;nested&nbsp;exception&nbsp;is&nbsp;org.springframework.beans.factory.NoSuchBeanDefinitionException:&nbsp;No&nbsp;qualifying&nbsp;bean&nbsp;of&nbsp;type&nbsp;'com.lzc.server.EmpServer'&nbsp;available:&nbsp;expected&nbsp;at&nbsp;least&nbsp;1&nbsp;bean&nbsp;which&nbsp;qualifies&nbsp;as&nbsp;autowire&nbsp;candidate.&nbsp;Dependency&nbsp;annotations:&nbsp;{@org.springframework.beans.factory.annotation.Autowired(required=true)} &nbsp;&nbsp;&nbsp;&nbsp;at&nbsp;org.springframework.beans.factory.annotation.AutowiredAnnotationBeanPostProcessor$AutowiredFieldElement.inject(AutowiredAnnotationBeanPostProcessor.java:588) &nbsp;&nbsp;&nbsp;&nbsp;at&nbsp;org.springframework.beans.factory.annotation.InjectionMetadata.inject(InjectionMetadata.java:88) &nbsp;&nbsp;&nbsp;&nbsp;at&nbsp;org.springframework.beans.factory.annotation.AutowiredAnnotationBeanPostProcessor.postProcessPropertyValues(AutowiredAnnotationBeanPostProcessor.java:366) &nbsp;&nbsp;&nbsp;&nbsp;at&nbsp;org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.populateBean(AbstractAutowireCapableBeanFactory.java:1268) &nbsp;&nbsp;&nbsp;&nbsp;at&nbsp;org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.doCreateBean(AbstractAutowireCapableBeanFactory.java:553) &nbsp;&nbsp;&nbsp;&nbsp;at&nbsp;org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBean(AbstractAutowireCapableBeanFactory.java:483) &nbsp;&nbsp;&nbsp;&nbsp;at&nbsp;org.springframework.beans.factory.support.AbstractBeanFactory$1.getObject(AbstractBeanFactory.java:312) &nbsp;&nbsp;&nbsp;&nbsp;at&nbsp;org.springframework.beans.factory.support.DefaultSingletonBeanRegistry.getSingleton(DefaultSingletonBeanRegistry.java:230) &nbsp;&nbsp;&nbsp;&nbsp;at&nbsp;org.springframework.beans.factory.support.AbstractBeanFactory.doGetBean(AbstractBeanFactory.java:308) &nbsp;&nbsp;&nbsp;&nbsp;at&nbsp;org.springframework.beans.factory.support.AbstractBeanFactory.getBean(AbstractBeanFactory.java:197) &nbsp;&nbsp;&nbsp;&nbsp;at&nbsp;org.springframework.beans.factory.support.DefaultListableBeanFactory.preInstantiateSingletons(DefaultListableBeanFactory.java:761) &nbsp;&nbsp;&nbsp;&nbsp;at&nbsp;org.springframework.context.support.AbstractApplicationContext.finishBeanFactoryInitialization(AbstractApplicationContext.java:867) &nbsp;&nbsp;&nbsp;&nbsp;at&nbsp;org.springframework.context.support.AbstractApplicationContext.refresh(AbstractApplicationContext.java:543) &nbsp;&nbsp;&nbsp;&nbsp;at&nbsp;org.springframework.web.servlet.FrameworkServlet.configureAndRefreshWebApplicationContext(FrameworkServlet.java:668) &nbsp;&nbsp;&nbsp;&nbsp;at&nbsp;org.springframework.web.servlet.FrameworkServlet.createWebApplicationContext(FrameworkServlet.java:634) &nbsp;&nbsp;&nbsp;&nbsp;at&nbsp;org.springframework.web.servlet.FrameworkServlet.createWebApplicationContext(FrameworkServlet.java:682) &nbsp;&nbsp;&nbsp;&nbsp;at&nbsp;org.springframework.web.servlet.FrameworkServlet.initWebApplicationContext(FrameworkServlet.java:553) &nbsp;&nbsp;&nbsp;&nbsp;at&nbsp;org.springframework.web.servlet.FrameworkServlet.initServletBean(FrameworkServlet.java:494) &nbsp;&nbsp;&nbsp;&nbsp;at&nbsp;org.springframework.web.servlet.HttpServletBean.init(HttpServletBean.java:171) &nbsp;&nbsp;&nbsp;&nbsp;at&nbsp;javax.servlet.GenericServlet.init(GenericServlet.java:158) &nbsp;&nbsp;&nbsp;&nbsp;at&nbsp;org.apache.catalina.core.StandardWrapper.initServlet(StandardWrapper.java:1188) &nbsp;&nbsp;&nbsp;&nbsp;at&nbsp;org.apache.catalina.core.StandardWrapper.loadServlet(StandardWrapper.java:1132) &nbsp;&nbsp;&nbsp;&nbsp;at&nbsp;org.apache.catalina.core.StandardWrapper.allocate(StandardWrapper.java:811) &nbsp;&nbsp;&nbsp;&nbsp;at&nbsp;org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:135) &nbsp;&nbsp;&nbsp;&nbsp;at&nbsp;org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:94) &nbsp;&nbsp;&nbsp;&nbsp;at&nbsp;org.apache.catalina.authenticator.AuthenticatorBase.invoke(AuthenticatorBase.java:496) &nbsp;&nbsp;&nbsp;&nbsp;at&nbsp;org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:141) &nbsp;&nbsp;&nbsp;&nbsp;at&nbsp;org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:79) &nbsp;&nbsp;&nbsp;&nbsp;at&nbsp;org.apache.catalina.valves.AbstractAccessLogValve.invoke(AbstractAccessLogValve.java:620) &nbsp;&nbsp;&nbsp;&nbsp;at&nbsp;org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:88) &nbsp;&nbsp;&nbsp;&nbsp;at&nbsp;org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:502) &nbsp;&nbsp;&nbsp;&nbsp;at&nbsp;org.apache.coyote.http11.AbstractHttp11Processor.process(AbstractHttp11Processor.java:1132) &nbsp;&nbsp;&nbsp;&nbsp;at&nbsp;org.apache.coyote.AbstractProtocol$AbstractConnectionHandler.process(AbstractProtocol.java:684) &nbsp;&nbsp;&nbsp;&nbsp;at&nbsp;org.apache.tomcat.util.net.NioEndpoint$SocketProcessor.doRun(NioEndpoint.java:1539) &nbsp;&nbsp;&nbsp;&nbsp;at&nbsp;org.apache.tomcat.util.net.NioEndpoint$SocketProcessor.run(NioEndpoint.java:1495) &nbsp;&nbsp;&nbsp;&nbsp;at&nbsp;java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1149) &nbsp;&nbsp;&nbsp;&nbsp;at&nbsp;java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:624) &nbsp;&nbsp;&nbsp;&nbsp;at&nbsp;org.apache.tomcat.util.threads.TaskThread$WrappingRunnable.run(TaskThread.java:61) &nbsp;&nbsp;&nbsp;&nbsp;at&nbsp;java.lang.Thread.run(Thread.java:748) Caused&nbsp;by:&nbsp;org.springframework.beans.factory.NoSuchBeanDefinitionException:&nbsp;No&nbsp;qualifying&nbsp;bean&nbsp;of&nbsp;type&nbsp;'com.lzc.server.EmpServer'&nbsp;available:&nbsp;expected&nbsp;at&nbsp;least&nbsp;1&nbsp;bean&nbsp;which&nbsp;qualifies&nbsp;as&nbsp;autowire&nbsp;candidate.&nbsp;Dependency&nbsp;annotations:&nbsp;{@org.springframework.beans.factory.annotation.Autowired(required=true)} &nbsp;&nbsp;&nbsp;&nbsp;at&nbsp;org.springframework.beans.factory.support.DefaultListableBeanFactory.raiseNoMatchingBeanFound(DefaultListableBeanFactory.java:1493) &nbsp;&nbsp;&nbsp;&nbsp;at&nbsp;org.springframework.beans.factory.support.DefaultListableBeanFactory.doResolveDependency(DefaultListableBeanFactory.java:1104) &nbsp;&nbsp;&nbsp;&nbsp;at&nbsp;org.springframework.beans.factory.support.DefaultListableBeanFactory.resolveDependency(DefaultListableBeanFactory.java:1066) &nbsp;&nbsp;&nbsp;&nbsp;at&nbsp;org.springframework.beans.factory.annotation.AutowiredAnnotationBeanPostProcessor$AutowiredFieldElement.inject(AutowiredAnnotationBeanPostProcessor.java:585) &nbsp;&nbsp;&nbsp;&nbsp;...&nbsp;38&nbsp;more </td> 
 </tr> 
 </tbody> 
</table>

核心错误提示：Dependency annotations: \{@org.springframework.beans.factory.annotation.Autowired(required=true)\}

错误说明：此错误为扫描不到server层的bean，扫描不到server层，则无法再web层中进行依赖注入，而页面调用时需要创建的时web层类的对象，则会报错无法创建'empWeb'。

配置二引起的错误：

错误说明：所有的Action页面全部404,后经探讨发现，是所有的web文件没有被spring扫描到，也就没有进行依赖注入。则所有的action全部扫描不到。

问题解决思路：

改配置写法一为以下写法：

<context:component-scan base-package="com.lzc.web">
 	
 	<context:include-filter type="annotation" expression="org.springframework.stereotype.Controller"/>
 </context:component-scan>

改配置写法二为以下写法：

<context:component-scan base-package="com.lzc.server">
 	
 	<context:include-filter type="annotation" expression="org.springframework.stereotype.Service"/>
 </context:component-scan>

既：去掉 base-package="com.lzc.web.\*" 中的“.\*”

问题解决思路：

base-package 指的是扫描器从那个包开始扫描， "com.lzc.web.\*" 指的是扫描 web包下面的任何包，也就是说 \* 通配符是改变了扫描基于的包了，不再是 web 而是 web 里面的各个子包。而我的 web类是放在这个包下的，扫的是根包里的子包的类而不是根包里的类，当然就搜索不到 web层下的类了。

详情请参考我的笔记信息：

[http://note.youdao.com/noteshare?id=3806860eb1caff3c1f800cf0318559d2][http_note.youdao.com_noteshare_id_3806860eb1caff3c1f800cf0318559d2]

参考文档：

作者：阪本先生

链接：https://www.jianshu.com/p/e7f66c6959b9

[http_note.youdao.com_noteshare_id_3806860eb1caff3c1f800cf0318559d2]: http://note.youdao.com/noteshare?id=3806860eb1caff3c1f800cf0318559d2