@Service
public class serviceImpl implements service {
//引用类型自动注入@Autowired, @Resource
@Resource
private com.dao.studentDAO studentDAO;
有写注解 及 <context:component-scan base-package="com.service1"/>
org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'serviceImpl': Injection of resource dependencies failed; nested exceptiohttps://blog.csdn.net/yeahPeng11/article/details/114488808n is org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'studentDAO' defined in file [D:\tomcat\apache-tomcat-9.0.46\webapps\SSm01_war\WEB-INF\classes\com\dao\studentDAO.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 class path resource [applicationContext.xml]: Invocation of init method failed; nested exception is org.apache.ibatis.builder.BuilderException: Error creating document instance. Cause: org.xml.sax.SAXParseException; lineNumber: 23; columnNumber: 3; 鍏冪礌绫诲瀷 "settings" 蹇呴』鐢卞尮閰嶇殑缁撴潫鏍囪 "" 缁堟銆�
at org.springframework.context.annotation.CommonAnnotationBeanPostProcessor.postProcessProperties(CommonAnnotationBeanPostProcessor.java:337)
at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.populateBean(AbstractAutowireCapableBeanFactory.java:1422)
at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.doCreateBean(AbstractAutowireCapableBeanFactory.java:594)
at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBean(AbstractAutowireCapableBeanFactory.java:517)
at org.springframework.beans.factory.support.AbstractBeanFactory.lambda$doGetBean$0(AbstractBeanFactory.java:323)
at org.springframework.beans.factory.support.DefaultSingletonBeanRegistry.getSingleton(DefaultSingletonBeanRegistry.java:222)
at org.springframework.beans.factory.support.AbstractBeanFactory.doGetBean(AbstractBeanFactory.java:321)
at org.springframework.beans.factory.support.AbstractBeanFactory.getBean(AbstractBeanFactory.java:202)
at org.springframework.beans.factory.support.DefaultListableBeanFactory.preInstantiateSingletons(DefaultListableBeanFactory.java:882)
at org.springframework.context.support.AbstractApplicationContext.finishBeanFactoryInitialization(AbstractApplicationContext.java:878)
at org.springframework.context.support.AbstractApplicationContext.refresh(AbstractApplicationContext.java:550)
at org.springframework.web.context.ContextLoader.configureAndRefreshWebApplicationContext(ContextLoader.java:401)
at org.springframework.web.context.ContextLoader.initWebApplicationContext(ContextLoader.java:292)
at org.springframework.web.context.ContextLoaderListener.contextInitialized(ContextLoaderListener.java:103)
at org.apache.catalina.core.StandardContext.listenerStart(StandardContext.java:4716)
at org.apache.catalina.core.StandardContext.startInternal(StandardContext.java:5172)
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:692)
at org.apache.catalina.startup.HostConfig.manageApp(HostConfig.java:1775)
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:460)
at org.apache.catalina.mbeans.MBeanFactory.createStandardContext(MBeanFactory.java:408)
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 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 javax.management.remote.rmi.RMIConnectionImpl.doPrivilegedOperation(RMIConnectionImpl.java:1401)
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:357)
at sun.rmi.transport.Transport$1.run(Transport.java:200)
at sun.rmi.transport.Transport$1.run(Transport.java:197)
at java.security.AccessController.doPrivileged(Native Method)
at sun.rmi.transport.Transport.serviceCall(Transport.java:196)
at sun.rmi.transport.tcp.TCPTransport.handleMessages(TCPTransport.java:573)
at sun.rmi.transport.tcp.TCPTransport$ConnectionHandler.run0(TCPTransport.java:834)
at sun.rmi.transport.tcp.TCPTransport$ConnectionHandler.lambda$run$0(TCPTransport.java:688)
at java.security.AccessController.doPrivileged(Native Method)
at sun.rmi.transport.tcp.TCPTransport$ConnectionHandler.run(TCPTransport.java:687)
at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1149)
at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:624)
at java.lang.Thread.run(Thread.java:748)
Caused by: org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'studentDAO' defined in file [D:\tomcat\apache-tomcat-9.0.46\webapps\SSm01_war\WEB-INF\classes\com\dao\studentDAO.class]: Cannot resolve reference to bean 'sqlSessionFactory' while setting bean property 'sqlSessionFactory'; nested exception is org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'sqlSessionFactory' defined in class path resource [applicationContext.xml]: Invocation of init method failed; nested exception is org.apache.ibatis.builder.BuilderException: Error creating document instance. Cause: org.xml.sax.SAXParseException; lineNumber: 23; columnNumber: 3; 鍏冪礌绫诲瀷 "settings" 蹇呴』鐢卞尮閰嶇殑缁撴潫鏍囪 "" 缁堟銆�
at org.springframework.beans.factory.support.BeanDefinitionValueResolver.resolveReference(BeanDefinitionValueResolver.java:342)
at org.springframework.beans.factory.support.BeanDefinitionValueResolver.resolveValueIfNecessary(BeanDefinitionValueResolver.java:113)
at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.applyPropertyValues(AbstractAutowireCapableBeanFactory.java:1699)
at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.populateBean(AbstractAutowireCapableBeanFactory.java:1444)
at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.doCreateBean(AbstractAutowireCapableBeanFactory.java:594)
at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBean(AbstractAutowireCapableBeanFactory.java:517)
at org.springframework.beans.factory.support.AbstractBeanFactory.lambda$doGetBean$0(AbstractBeanFactory.java:323)
at org.springframework.beans.factory.support.DefaultSingletonBeanRegistry.getSingleton(DefaultSingletonBeanRegistry.java:222)
at org.springframework.beans.factory.support.AbstractBeanFactory.doGetBean(AbstractBeanFactory.java:321)
at org.springframework.beans.factory.support.AbstractBeanFactory.getBean(AbstractBeanFactory.java:207)
at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.resolveBeanByName(AbstractAutowireCapableBeanFactory.java:454)
at org.springframework.context.annotation.CommonAnnotationBeanPostProcessor.autowireResource(CommonAnnotationBeanPostProcessor.java:543)
at org.springframework.context.annotation.CommonAnnotationBeanPostProcessor.getResource(CommonAnnotationBeanPostProcessor.java:513)
at org.springframework.context.annotation.CommonAnnotationBeanPostProcessor$ResourceElement.getResourceToInject(CommonAnnotationBeanPostProcessor.java:653)
at org.springframework.beans.factory.annotation.InjectionMetadata$InjectedElement.inject(InjectionMetadata.java:239)
at org.springframework.beans.factory.annotation.InjectionMetadata.inject(InjectionMetadata.java:130)
at org.springframework.context.annotation.CommonAnnotationBeanPostProcessor.postProcessProperties(CommonAnnotationBeanPostProcessor.java:334)
... 58 more
Caused by: org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'sqlSessionFactory' defined in class path resource [applicationContext.xml]: Invocation of init method failed; nested exception is org.apache.ibatis.builder.BuilderException: Error creating document instance. Cause: org.xml.sax.SAXParseException; lineNumber: 23; columnNumber: 3; 鍏冪礌绫诲瀷 "settings" 蹇呴』鐢卞尮閰嶇殑缁撴潫鏍囪 "" 缁堟銆�
at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.initializeBean(AbstractAutowireCapableBeanFactory.java:1796)
at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.doCreateBean(AbstractAutowireCapableBeanFactory.java:595)
at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBean(AbstractAutowireCapableBeanFactory.java:517)
at org.springframework.beans.factory.support.AbstractBeanFactory.lambda$doGetBean$0(AbstractBeanFactory.java:323)
at org.springframework.beans.factory.support.DefaultSingletonBeanRegistry.getSingleton(DefaultSingletonBeanRegistry.java:222)
at org.springframework.beans.factory.support.AbstractBeanFactory.doGetBean(AbstractBeanFactory.java:321)
at org.springframework.beans.factory.support.AbstractBeanFactory.getBean(AbstractBeanFactory.java:202)
at org.springframework.beans.factory.support.BeanDefinitionValueResolver.resolveReference(BeanDefinitionValueResolver.java:330)
... 74 more
Caused by: org.apache.ibatis.builder.BuilderException: Error creating document instance. Cause: org.xml.sax.SAXParseException; lineNumber: 23; columnNumber: 3; 鍏冪礌绫诲瀷 "settings" 蹇呴』鐢卞尮閰嶇殑缁撴潫鏍囪 "" 缁堟銆�
at org.apache.ibatis.parsing.XPathParser.createDocument(XPathParser.java:260)
at org.apache.ibatis.parsing.XPathParser.(XPathParser.java:126)
at org.apache.ibatis.builder.xml.XMLConfigBuilder.(XMLConfigBuilder.java:81)
at org.mybatis.spring.SqlSessionFactoryBean.buildSqlSessionFactory(SqlSessionFactoryBean.java:406)
at org.mybatis.spring.SqlSessionFactoryBean.afterPropertiesSet(SqlSessionFactoryBean.java:380)
at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.invokeInitMethods(AbstractAutowireCapableBeanFactory.java:1855)
at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.initializeBean(AbstractAutowireCapableBeanFactory.java:1792)
... 81 more
Caused by: org.xml.sax.SAXParseException; lineNumber: 23; columnNumber: 3; 鍏冪礌绫诲瀷 "settings" 蹇呴』鐢卞尮閰嶇殑缁撴潫鏍囪 "" 缁堟銆�
at com.sun.org.apache.xerces.internal.util.ErrorHandlerWrapper.createSAXParseException(ErrorHandlerWrapper.java:204)
at com.sun.org.apache.xerces.internal.util.ErrorHandlerWrapper.fatalError(ErrorHandlerWrapper.java:178)
at com.sun.org.apache.xerces.internal.impl.XMLErrorReporter.reportError(XMLErrorReporter.java:400)
at com.sun.org.apache.xerces.internal.impl.XMLErrorReporter.reportError(XMLErrorReporter.java:327)
at com.sun.org.apache.xerces.internal.impl.XMLScanner.reportFatalError(XMLScanner.java:1472)
at com.sun.org.apache.xerces.internal.impl.XMLDocumentFragmentScannerImpl.scanEndElement(XMLDocumentFragmentScannerImpl.java:1751)
at com.sun.org.apache.xerces.internal.impl.XMLDocumentFragmentScannerImpl$FragmentContentDriver.next(XMLDocumentFragmentScannerImpl.java:2969)
at com.sun.org.apache.xerces.internal.impl.XMLDocumentScannerImpl.next(XMLDocumentScannerImpl.java:605)
at com.sun.org.apache.xerces.internal.impl.XMLDocumentFragmentScannerImpl.scanDocument(XMLDocumentFragmentScannerImpl.java:507)
at com.sun.org.apache.xerces.internal.parsers.XML11Configuration.parse(XML11Configuration.java:867)
at com.sun.org.apache.xerces.internal.parsers.XML11Configuration.parse(XML11Configuration.java:796)
at com.sun.org.apache.xerces.internal.parsers.XMLParser.parse(XMLParser.java:142)
at com.sun.org.apache.xerces.internal.parsers.DOMParser.parse(DOMParser.java:247)
at com.sun.org.apache.xerces.internal.jaxp.DocumentBuilderImpl.parse(DocumentBuilderImpl.java:339)
at org.apache.ibatis.parsing.XPathParser.createDocument(XPathParser.java:258)
仔细看这一句即可，其他的报错都是没用的
Caused by: org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'studentDAO' defined in file [D:.....
意思就是创建studentDAO这个对象失败，bean配置没用生效
解决办法：
如果你使用springboot框架，无需配置bean标签，底层有自动实现的方法
如果你使用简单的spring配置了bean标签，仔细检查一下有没有配置错误，另外创建对象注解使用@Autowired
下面是我配置的，看看和你的有没有出入，我的已经测试过了
<!-- 定义SqlSessionFactory，管理mybatis的数据库连接sqksession对象-->
<bean class="com.baomidou.mybatisplus.extension.spring.MybatisSqlSessionFactoryBean" id="sqlSessionFactory">
<property name="dataSource" ref="dataSource"/>
<!--配置实体类的包名，自动为实体配置短类名的别名-->
<property name="typeAliasesPackage" value="com.xxx.entity"/>
<property name="mapperLocations">
<!-- 配置mapper.xml的路径-->
<list>
<value>classpath:com.xxx.dao/*Dao.xml</value>
</list>
</property>
<property name="plugins">
<array>
<bean class="com.github.pagehelper.PageInterceptor"/>
</array>
</property>
</bean>
<!--让spring扫描dao包，创建出dao接口的实现类，并把实现类配置为bean标签
自动创建Mapper实现类对象
自动扫描basePackage包下的Mapper接口，自动创建Mapper接口的实现类对象-->
<bean class="org.mybatis.spring.mapper.MapperScannerConfigurer">
<!-- mapper实现类对象的id规则：接口名首字母小写
UserMapper ==> userMapper
BookMapper ==> bookMapper -->
<property name="basePackage" value="com.xxx.dao"/>
</bean>
你主要看dao的和service的配置即可，value后面是对应文件的包路径
如果对你有帮助，记得采纳一下哦~，谢谢^_^
参考：https://blog.csdn.net/beernum/article/details/87928880
mapper最后发现缺少头部配置文件,这行：
[applicationContext.xml]: Invocation of init method failed; nested exception is org.apache.ibatis.builder.BuilderException: Error creating document instance. Cause: org.xml.sax.SAXParseException; lineNumber: 23; columnNumber: 3;
applicationContext.xml lineNumber: 23;
写了啥东西?
Error creating bean with name 'serviceImpl': Injection of resource dependencies failed; nested exceptiohttps://blog.csdn.net/yeahPeng11/article/details/114488808n is org.springframework.beans.factory.BeanCreationException:
Error creating bean with name 'studentDAO' defined in file [D:\tomcat\apache-tomcat-9.0.46\webapps\SSm01_war\WEB-INF\classes\com\dao\studentDAO.class]
serviceImpl：资源依赖项的连接失败
studentDAO：bean注入失败