org.springframework.beans.factory.UnsatisfiedDependencyException：报错解决

可以理解为依赖失败吧，找不到依赖

部分报错如下：

org.springframework.beans.factory.UnsatisfiedDependencyException: Error creating bean with name 'pageService': Unsatisfied dependency expressed through field 'pageInfoMepper'; nested exception is org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'pageInfoMepper' defined in file [D:\project\IDEAProject\demoPage\out\artifacts\WEB-INF\classes\com\liglei\mapper\PageInfoMepper.class]: Cannot resolve reference to bean 'sqlSessionFactory' while setting bean property 'sqlSessionFactory'; nested exception is org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'sqlSessionFactory' defined in file [D:\project\IDEAProject\demoPage\out\artifacts\WEB-INF\classes\applicationContext.xml]: Invocation of init method failed; nested exception is org.springframework.core.NestedIOException: Failed to parse config resource: class path resource [mybatis-config.xml]; nested exception is org.apache.ibatis.builder.BuilderException: Error parsing SQL Mapper Configuration. Cause: org.apache.ibatis.builder.BuilderException: Error resolving class. Cause: org.apache.ibatis.type.TypeException: Could not resolve type alias 'com.github.pagehelper.PageInterceptor'.  Cause: java.lang.ClassNotFoundException: Cannot find class: com.github.pagehelper.PageInterceptor
	at org.springframework.beans.factory.annotation.AutowiredAnnotationBeanPostProcessor$AutowiredFieldElement.inject(AutowiredAnnotationBeanPostProcessor.java:596)
	at org.springframework.beans.factory.annotation.InjectionMetadata.inject(InjectionMetadata.java:90)
	at org.springframework.beans.factory.annotation.AutowiredAnnotationBeanPostProcessor.postProcessProperties(AutowiredAnnotationBeanPostProcessor.java:374)
	at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.populateBean(AbstractAutowireCapableBeanFactory.java:1411)
	at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.doCreateBean(AbstractAutowireCapableBeanFactory.java:592)
	at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBean(AbstractAutowireCapableBeanFactory.java:515)
	at org.springframework.beans.factory.support.AbstractBeanFactory.lambda$doGetBean$0(AbstractBeanFactory.java:320)
	at org.springframework.beans.factory.support.DefaultSingletonBeanRegistry.getSingleton(DefaultSingletonBeanRegistry.java:222)
	at org.springframework.beans.factory.support.AbstractBeanFactory.doGetBean(AbstractBeanFactory.java:318)
	at org.springframework.beans.factory.support.AbstractBeanFactory.getBean(AbstractBeanFactory.java:199)
	at org.springframework.beans.factory.support.DefaultListableBeanFactory.preInstantiateSingletons(DefaultListableBeanFactory.java:843)
	at org.springframework.context.support.AbstractApplicationContext.finishBeanFactoryInitialization(AbstractApplicationContext.java:877)
	at org.springframework.context.support.AbstractApplicationContext.refresh(AbstractApplicationContext.java:549)
	at org.springframework.web.context.ContextLoader.configureAndRefreshWebApplicationContext(ContextLoader.java:400)
	at org.springframework.web.context.ContextLoader.initWebApplicationContext(ContextLoader.java:291)
	at org.springframework.web.context.ContextLoaderListener.contextInitialized(ContextLoaderListener.java:103)
	at org.apache.catalina.core.StandardContext.listenerStart(StandardContext.java:4643)
	at org.apache.catalina.core.StandardContext.startInternal(StandardContext.java:5109)
	at org.apache.catalina.util.LifecycleBase.start(LifecycleBase.java:183)
	at org.apache.catalina.core.ContainerBase.addChildInternal(ContainerBase.java:743)
	at org.apache.catalina.core.ContainerBase.addChild(ContainerBase.java:719)
	at org.apache.catalina.core.StandardHost.addChild(StandardHost.java:703)
	at org.apache.catalina.startup.HostConfig.manageApp(HostConfig.java:1737)
	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:287)
	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:457)
	at org.apache.catalina.mbeans.MBeanFactory.createStandardContext(MBeanFactory.java:406)
	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:287)
	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)
    .......
    .......

解决方案：

1. 先看看Service层类上的注解有没有加上或者是加错，应给是@Service，注解是否引用了Spring类，不要导成别的包了，看清包的路径。

2. 还有就是如果Service层分成了接口和实现类看看实现类有没有加注解（@Service），看看有没有实现类。

3. 看看配置文件.xml，有没有启动自动扫描Service所在的包

   <context:component-scan base-package="com.liglei.service"></context:component-scan>
   

4. 看看jar包是否下载完整，是否有这个jar包

5. 就是看看下图红色方框内是否有包没导进去，有就按照下面的步骤完成：

   File–>Project Structure–>Artifacts–>右键demoPage–>Put into Output Root–>OK

确保以上步骤没问题的，重启一下项目试试~

本人问题已解决!

还有问题的欢迎朋友们的评论与交流!

解决方案不完整，如果有大神补充的欢迎赐教~