mybatis配置Mapper.xml文件时遇到的问题及解决
作者：找找Bug
mybatis配置Mapper.xml文件遇到的问题
错误提示
org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'userServiceImpl': Injection of resource dependencies failed; nested exception is org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'userDao' defined in file [/home/hedingqin/GraduateDesign/mySupermarket/out/artifacts/mySupermarket_war_exploded/WEB-INF/classes/sms/dao/UserDao.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.springframework.core.NestedIOException: Failed to parse mapping resource: 'file [/home/hedingqin/GraduateDesign/mySupermarket/out/artifacts/mySupermarket_war_exploded/WEB-INF/classes/sms/mapping/UserDao.xml]'; nested exception is org.apache.ibatis.builder.BuilderException: Error parsing Mapper XML. Cause: org.apache.ibatis.builder.BuilderException: Error resolving class. Cause: org.apache.ibatis.type.TypeException: Could not resolve type alias 'User'. Cause: java.lang.ClassNotFoundException: Cannot find class: User
at org.springframework.context.annotation.CommonAnnotationBeanPostProcessor.postProcessPropertyValues(CommonAnnotationBeanPostProcessor.java:308)
at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.populateBean(AbstractAutowireCapableBeanFactory.java:1208)
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:303)
at org.springframework.beans.factory.support.DefaultSingletonBeanRegistry.getSingleton(DefaultSingletonBeanRegistry.java:230)
at org.springframework.beans.factory.support.AbstractBeanFactory.doGetBean(AbstractBeanFactory.java:299)
at org.springframework.beans.factory.support.AbstractBeanFactory.getBean(AbstractBeanFactory.java:194)
at org.springframework.beans.factory.support.DefaultListableBeanFactory.preInstantiateSingletons(DefaultListableBeanFactory.java:755)
at org.springframework.context.support.AbstractApplicationContext.finishBeanFactoryInitialization(AbstractApplicationContext.java:762)
at org.springframework.context.support.AbstractApplicationContext.refresh(AbstractApplicationContext.java:480)
at org.springframework.web.context.ContextLoader.configureAndRefreshWebApplicationContext(ContextLoader.java:434)
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:4817)
at org.apache.catalina.core.StandardContext.startInternal(StandardContext.java:5283)
at org.apache.catalina.util.LifecycleBase.start(LifecycleBase.java:150)
at org.apache.catalina.core.ContainerBase.addChildInternal(ContainerBase.java:754)
at org.apache.catalina.core.ContainerBase.addChild(ContainerBase.java:730)
at org.apache.catalina.core.StandardHost.addChild(StandardHost.java:734)
at org.apache.catalina.startup.HostConfig.manageApp(HostConfig.java:1736)
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:300)
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:483)
at org.apache.catalina.mbeans.MBeanFactory.createStandardContext(MBeanFactory.java:432)
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:300)
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: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 'userDao' defined in file [/home/hedingqin/GraduateDesign/mySupermarket/out/artifacts/mySupermarket_war_exploded/WEB-INF/classes/sms/dao/UserDao.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.springframework.core.NestedIOException: Failed to parse mapping resource: 'file [/home/hedingqin/GraduateDesign/mySupermarket/out/artifacts/mySupermarket_war_exploded/WEB-INF/classes/sms/mapping/UserDao.xml]'; nested exception is org.apache.ibatis.builder.BuilderException: Error parsing Mapper XML. Cause: org.apache.ibatis.builder.BuilderException: Error resolving class. Cause: org.apache.ibatis.type.TypeException: Could not resolve type alias 'User'. Cause: java.lang.ClassNotFoundException: Cannot find class: User
at org.springframework.beans.factory.support.BeanDefinitionValueResolver.resolveReference(BeanDefinitionValueResolver.java:359)
at org.springframework.beans.factory.support.BeanDefinitionValueResolver.resolveValueIfNecessary(BeanDefinitionValueResolver.java:108)
at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.applyPropertyValues(AbstractAutowireCapableBeanFactory.java:1475)
at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.populateBean(AbstractAutowireCapableBeanFactory.java:1220)
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$1.getObject(AbstractBeanFactory.java:303)
at org.springframework.beans.factory.support.DefaultSingletonBeanRegistry.getSingleton(DefaultSingletonBeanRegistry.java:230)
at org.springframework.beans.factory.support.AbstractBeanFactory.doGetBean(AbstractBeanFactory.java:299)
at org.springframework.beans.factory.support.AbstractBeanFactory.getBean(AbstractBeanFactory.java:199)
at org.springframework.context.annotation.CommonAnnotationBeanPostProcessor.autowireResource(CommonAnnotationBeanPostProcessor.java:461)
at org.springframework.context.annotation.CommonAnnotationBeanPostProcessor.getResource(CommonAnnotationBeanPostProcessor.java:435)
at org.springframework.context.annotation.CommonAnnotationBeanPostProcessor$ResourceElement.getResourceToInject(CommonAnnotationBeanPostProcessor.java:559)
at org.springframework.beans.factory.annotation.InjectionMetadata$InjectedElement.inject(InjectionMetadata.java:169)
at org.springframework.beans.factory.annotation.InjectionMetadata.inject(InjectionMetadata.java:88)
at org.springframework.context.annotation.CommonAnnotationBeanPostProcessor.postProcessPropertyValues(CommonAnnotationBeanPostProcessor.java:305)
... 60 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.springframework.core.NestedIOException: Failed to parse mapping resource: 'file [/home/hedingqin/GraduateDesign/mySupermarket/out/artifacts/mySupermarket_war_exploded/WEB-INF/classes/sms/mapping/UserDao.xml]'; nested exception is org.apache.ibatis.builder.BuilderException: Error parsing Mapper XML. Cause: org.apache.ibatis.builder.BuilderException: Error resolving class. Cause: org.apache.ibatis.type.TypeException: Could not resolve type alias 'User'. Cause: java.lang.ClassNotFoundException: Cannot find class: User
at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.initializeBean(AbstractAutowireCapableBeanFactory.java:1572)
at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.doCreateBean(AbstractAutowireCapableBeanFactory.java:539)
at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBean(AbstractAutowireCapableBeanFactory.java:476)
at org.springframework.beans.factory.support.AbstractBeanFactory$1.getObject(AbstractBeanFactory.java:303)
at org.springframework.beans.factory.support.DefaultSingletonBeanRegistry.getSingleton(DefaultSingletonBeanRegistry.java:230)
at org.springframework.beans.factory.support.AbstractBeanFactory.doGetBean(AbstractBeanFactory.java:299)
at org.springframework.beans.factory.support.AbstractBeanFactory.getBean(AbstractBeanFactory.java:194)
at org.springframework.beans.factory.support.BeanDefinitionValueResolver.resolveReference(BeanDefinitionValueResolver.java:351)
... 75 more
Caused by: org.springframework.core.NestedIOException: Failed to parse mapping resource: 'file [/home/hedingqin/GraduateDesign/mySupermarket/out/artifacts/mySupermarket_war_exploded/WEB-INF/classes/sms/mapping/UserDao.xml]'; nested exception is org.apache.ibatis.builder.BuilderException: Error parsing Mapper XML. Cause: org.apache.ibatis.builder.BuilderException: Error resolving class. Cause: org.apache.ibatis.type.TypeException: Could not resolve type alias 'User'. Cause: java.lang.ClassNotFoundException: Cannot find class: User
at org.mybatis.spring.SqlSessionFactoryBean.buildSqlSessionFactory(SqlSessionFactoryBean.java:468)
at org.mybatis.spring.SqlSessionFactoryBean.afterPropertiesSet(SqlSessionFactoryBean.java:343)
at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.invokeInitMethods(AbstractAutowireCapableBeanFactory.java:1631)
at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.initializeBean(AbstractAutowireCapableBeanFactory.java:1568)
... 82 more
Caused by: org.apache.ibatis.builder.BuilderException: Error parsing Mapper XML. Cause: org.apache.ibatis.builder.BuilderException: Error resolving class. Cause: org.apache.ibatis.type.TypeException: Could not resolve type alias 'User'. Cause: java.lang.ClassNotFoundException: Cannot find class: User
at org.apache.ibatis.builder.xml.XMLMapperBuilder.configurationElement(XMLMapperBuilder.java:120)
at org.apache.ibatis.builder.xml.XMLMapperBuilder.parse(XMLMapperBuilder.java:92)
at org.mybatis.spring.SqlSessionFactoryBean.buildSqlSessionFactory(SqlSessionFactoryBean.java:466)
... 85 more
Caused by: org.apache.ibatis.builder.BuilderException: Error resolving class. Cause: org.apache.ibatis.type.TypeException: Could not resolve type alias 'User'. Cause: java.lang.ClassNotFoundException: Cannot find class: User
at org.apache.ibatis.builder.BaseBuilder.resolveClass(BaseBuilder.java:103)
at org.apache.ibatis.builder.xml.XMLStatementBuilder.parseStatementNode(XMLStatementBuilder.java:66)
at org.apache.ibatis.builder.xml.XMLMapperBuilder.buildStatementFromContext(XMLMapperBuilder.java:135)
at org.apache.ibatis.builder.xml.XMLMapperBuilder.buildStatementFromContext(XMLMapperBuilder.java:128)
at org.apache.ibatis.builder.xml.XMLMapperBuilder.configurationElement(XMLMapperBuilder.java:118)
... 87 more
Caused by: org.apache.ibatis.type.TypeException: Could not resolve type alias 'User'. Cause: java.lang.ClassNotFoundException: Cannot find class: User
at org.apache.ibatis.type.TypeAliasRegistry.resolveAlias(TypeAliasRegistry.java:117)
at org.apache.ibatis.builder.BaseBuilder.resolveAlias(BaseBuilder.java:130)
at org.apache.ibatis.builder.BaseBuilder.resolveClass(BaseBuilder.java:101)
... 91 more
Caused by: java.lang.ClassNotFoundException: Cannot find class: User
at org.apache.ibatis.io.ClassLoaderWrapper.classForName(ClassLoaderWrapper.java:190)
at org.apache.ibatis.io.ClassLoaderWrapper.classForName(ClassLoaderWrapper.java:89)
at org.apache.ibatis.io.Resources.classForName(Resources.java:256)
25-Apr-2020 21:42:42.428 严重 [RMI TCP Connection(2)-127.0.0.1] org.apache.catalina.core.StandardContext.startInternal One or more listeners failed to start. Full details will be found in the appropriate container log file
at org.apache.ibatis.type.TypeAliasRegistry.resolveAlias(TypeAliasRegistry.java:113)
... 93 more
25-Apr-2020 21:42:42.432 严重 [RMI TCP Connection(2)-127.0.0.1] org.apache.catalina.core.StandardContext.startInternal Context [/mySupermarket_war_exploded] startup failed due to previous errors
25-Apr-2020 21:42:42.443 警告 [RMI TCP Connection(2)-127.0.0.1] org.apache.catalina.loader.WebappClassLoaderBase.clearReferencesJdbc The web application [mySupermarket_war_exploded] registered the JDBC driver [com.alibaba.druid.proxy.DruidDriver] but failed to unregister it when the web application was stopped. To prevent a memory leak, the JDBC Driver has been forcibly unregistered.
25-Apr-2020 21:42:42.443 警告 [RMI TCP Connection(2)-127.0.0.1] org.apache.catalina.loader.WebappClassLoaderBase.clearReferencesJdbc The web application [mySupermarket_war_exploded] registered the JDBC driver [com.mysql.jdbc.Driver] but failed to unregister it when the web application was stopped. To prevent a memory leak, the JDBC Driver has been forcibly unregistered.
[2020-04-25 09:42:42,457] Artifact mySupermarket:war exploded: Error during artifact deployment. See server log for details.
25-Apr-2020 21:42:47.580 信息 [localhost-startStop-1] org.apache.catalina.startup.HostConfig.deployDirectory Deploying web application directory [/home/hedingqin/install/apache-tomcat-8.5.38/webapps/manager]
25-Apr-2020 21:42:47.621 信息 [localhost-startStop-1] org.apache.catalina.startup.HostConfig.deployDirectory Deployment of web application directory [/home/hedingqin/install/apache-tomcat-8.5.38/webapps/manager] has finished in [40] ms
错误原因及解决办法
原因：UserDao.xml中直接使用了User类的名字,应该写成User类的全称--包名加类名.只有这样才能识别出正确的类.
方法：写全称或者在mybatis中给User类起别名.
<typeAliases> <typeAlias alias="User" type="sms.entity.User" /> </typeAliases>
给sms.entity.User起了个别名User,这样在UserDao.xml文件中就可以直接使用User了.
mybatis的mapper.xml配置详情
提示：以下是本篇文章正文内容，下面案例可供参考
mapper.xml是什么？
namespace——指定Mapper接口。
resultMap —— 映射类，指定show类或者实体类。
注: resultType ——指定返回类型 例：resultType = Java.lang.Integer 则返回类型为Integer类型。
用法：查询多个值用 resultMap指定映射类。
查询单个值用 resultType指定返回类型。
id —— 映射别名。
可配置多个resultMap 指定映射。
注意：映射类需与接收类一致，否则会报show类与实体类无法转换异常。
使用步骤
SELECT company_id,our_person,our_contact,ourosite_email,order_no ,our_store_name FROM t_lawcase_our_party
where 1=1 and is_enable = '1'
<if test="orderNo!=null and orderNo !=''">
and order_no = #{orderNo}
</if>**resultMap** ： 指定映射对象。
注意：SQL语句写法需遵从Mybatis 语句写法。**JPA**写法在此不通用。
当SQL语句需要IN多个值时，需要用到**<foreach> 标签**，Mybatis 无法用IN（）这种JPA写法。
collection：指定集合名字item： 别名。（**注意后面SQL语句写法是IN 别名 ，而不是集合名字！！！**）separator：集合以什么方式隔开（逗号或者其他）@Param("deptIdList")：SQL 语句参数别名。SQL根据条件查询时需用到该注解**。
小结：mybatis 一定要注意SQL语句写法与映射类型，是使用resultMap 还是使用resultType。
总结
以上为个人经验，希望能给大家一个参考，也希望大家多多支持脚本之家。