Exception: Java.lang.IllegalArgumentException:Result Maps collection already contains ...

Post an exception that has bothered you for the afternoon, and the exception information is as follows:

November 24, 2017 9:26:07 a.m. Org.apache.catalina.core.ApplicationContext log Serious: standardwrapper.throwable Org.springframework.beans.factory.BeanCreationException:Error creating Bean with Name ' sqlsessionfactory ' defined in file [F:\JavaWeb\.metadata\.plugins\org.eclipse.wst.server.core\tmp1\wtpwebapps\jh_qisf\WEB-INF\classes\spring\ Spring-dao.xml]: Invocation of Init method failed; Nested exception is org.springframework.core.NestedIOException:Failed to parse mapping: ' File [resource. Metadata\.plugins\org.eclipse.wst.server.core\tmp1\wtpwebapps\jh_qisf\web-inf\classes\mapper\ Departmentmapper.xml] '; Nested exception is Org.apache.ibatis.builder.BuilderException:Error parsing Mapper XML. Cause:java.lang.IllegalArgumentException:Result Maps Collection already contains value for Cn.jinhai.qisf.dao.DepartmentMapper.BaseResultMap at Org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.initializeBean ( abstractautowirecapablebeanfactory.java:1574) 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.DefaultListableBeanFactory.preInstantiateSingletons ( defaultlistablebeanfactory.java:736) at Org.springframework.context.support.AbstractApplicationContext.finishBeanFactoryInitialization ( abstractapplicationcontext.java:757) at Org.springfraMework.context.support.AbstractApplicationContext.refresh (abstractapplicationcontext.java:480) at Org.springframework.web.servlet.FrameworkServlet.configureAndRefreshWebApplicationContext ( frameworkservlet.java:664) at Org.springframework.web.servlet.FrameworkServlet.createWebApplicationContext ( frameworkservlet.java:630) at Org.springframework.web.servlet.FrameworkServlet.createWebApplicationContext ( frameworkservlet.java:678) at Org.springframework.web.servlet.FrameworkServlet.initWebApplicationContext ( frameworkservlet.java:549) at Org.springframework.web.servlet.FrameworkServlet.initServletBean ( frameworkservlet.java:490) at Org.springframework.web.servlet.HttpServletBean.init (httpservletbean.java:136) at Javax.servlet.GenericServlet.init (genericservlet.java:158) at Org.apache.catalina.core.StandardWrapper.initServlet (standardwrapper.java:1269) at Org.apache.catalina.core.StandardWrapper.loadServlet (standardwrapper.java:1182) at Org.apache.catalina.core.StandardWrapper.allocatE (standardwrapper.java:853) at Org.apache.catalina.core.StandardWrapperValve.invoke (Standardwrappervalve.java : 134) at Org.apache.catalina.core.StandardContextValve.invoke (standardcontextvalve.java:110) at Org.apache.catalina.authenticator.AuthenticatorBase.invoke (authenticatorbase.java:506) at Org.apache.catalina.core.StandardHostValve.invoke (standardhostvalve.java:169) at Org.apache.catalina.valves.ErrorReportValve.invoke (errorreportvalve.java:103) at Org.apache.catalina.valves.AccessLogValve.invoke (accesslogvalve.java:962) at Org.apache.catalina.core.StandardEngineValve.invoke (standardenginevalve.java:116) at Org.apache.catalina.connector.CoyoteAdapter.service (coyoteadapter.java:445) at Org.apache.coyote.http11.AbstractHttp11Processor.process (abstracthttp11processor.java:1115) at Org.apache.coyote.abstractprotocol$abstractconnectionhandler.process (abstractprotocol.java:637) at Org.apache.tomcat.util.net.jioendpoint$socketprocessor.run (jioendpoint.java:316) at java.util.coNcurrent. Threadpoolexecutor.runworker (threadpoolexecutor.java:1149) at Java.util.concurrent.threadpoolexecutor$worker.run (threadpoolexecutor.java:624) at Org.apache.tomcat.util.threads.taskthread$wrappingrunnable.run (TaskThread.java : Java.lang.Thread.run (thread.java:748) caused by:org.springframework.core.NestedIOException:Failed to parse Mapping resource: ' File [F:\JavaWeb\.metadata\.plugins\org.eclipse.wst.server.core\tmp1\wtpwebapps\jh_qisf\ Web-inf\classes\mapper\departmentmapper.xml] '; Nested exception is Org.apache.ibatis.builder.BuilderException:Error parsing Mapper XML. Cause:java.lang.IllegalArgumentException:Result Maps Collection already contains value for Cn.jinhai.qisf.dao.DepartmentMapper.BaseResultMap at Org.mybatis.spring.SqlSessionFactoryBean.buildSqlSessionFactory (sqlsessionfactorybean.java:468) at Org.mybatis.spring.SqlSessionFactoryBean.afterPropertiesSet (sqlsessionfactorybean.java:343) at Org.springframework.beans.factory.support.AbstractAutowireCapAblebeanfactory.invokeinitmethods (abstractautowirecapablebeanfactory.java:1633) at Org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.initializeBean ( abstractautowirecapablebeanfactory.java:1570) ... More caused By:org.apache.ibatis.builder.BuilderException:Error parsing Mapper XML. Cause:java.lang.IllegalArgumentException:Result Maps Collection already contains value for Cn.jinhai.qisf.dao.DepartmentMapper.BaseResultMap at Org.apache.ibatis.builder.xml.XMLMapperBuilder.configurationElement (xmlmapperbuilder.java:120) at Org.apache.ibatis.builder.xml.XMLMapperBuilder.parse (xmlmapperbuilder.java:92) at Org.mybatis.spring.SqlSessionFactoryBean.buildSqlSessionFactory (sqlsessionfactorybean.java:466) ... Panax Notoginseng caused By:java.lang.IllegalArgumentException:Result Maps collection already contains value for Cn.jinhai.qisf.da O.departmentmapper.baseresultmap at Org.apache.ibatis.session.configuration$strictmap.put (Configuration.java:802 ) at Org.apache.ibAtis.session.configuration$strictmap.put (configuration.java:774) at Org.apache.ibatis.session.Configuration.addResultMap (configuration.java:556) at Org.apache.ibatis.builder.MapperBuilderAssistant.addResultMap (mapperbuilderassistant.java:217) at Org.apache.ibatis.builder.ResultMapResolver.resolve (resultmapresolver.java:47) at Org.apache.ibatis.builder.xml.XMLMapperBuilder.resultMapElement (xmlmapperbuilder.java:285) at Org.apache.ibatis.builder.xml.XMLMapperBuilder.resultMapElement (xmlmapperbuilder.java:252) at Org.apache.ibatis.builder.xml.XMLMapperBuilder.resultMapElements (xmlmapperbuilder.java:244) at Org.apache.ibatis.builder.xml.XMLMapperBuilder.configurationElement (xmlmapperbuilder.java:116) ... The more November 24, 2017 9:26:07 a.m. Org.apache.catalina.core.StandardWrapperValve invoke severity: Allocate exception for servlet m Vc-dispatcher Java.lang.IllegalArgumentException:Result Maps Collection already contains value for Cn.jinhai.qisf.dao.DepartmentMapper.BaseResultMap at Org.apAche.ibatis.session.configuration$strictmap.put (configuration.java:802) at Org.apache.ibatis.session.configuration$strictmap.put (configuration.java:774) at Org.apache.ibatis.session.Configuration.addResultMap (configuration.java:556) at Org.apache.ibatis.builder.MapperBuilderAssistant.addResultMap (mapperbuilderassistant.java:217) at Org.apache.ibatis.builder.ResultMapResolver.resolve (resultmapresolver.java:47) at Org.apache.ibatis.builder.xml.XMLMapperBuilder.resultMapElement (xmlmapperbuilder.java:285) at Org.apache.ibatis.builder.xml.XMLMapperBuilder.resultMapElement (xmlmapperbuilder.java:252) at Org.apache.ibatis.builder.xml.XMLMapperBuilder.resultMapElements (xmlmapperbuilder.java:244) at Org.apache.ibatis.builder.xml.XMLMapperBuilder.configurationElement (xmlmapperbuilder.java:116) at Org.apache.ibatis.builder.xml.XMLMapperBuilder.parse (xmlmapperbuilder.java:92) at Org.mybatis.spring.SqlSessionFactoryBean.buildSqlSessionFactory (sqlsessionfactorybean.java:466) at Org.mybatis. Spring. Sqlsessionfactorybean.afterpropertiesset (sqlsessionfactorybean.java:343) at Org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.invokeInitMethods ( abstractautowirecapablebeanfactory.java:1633) at Org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.initializeBean ( abstractautowirecapablebeanfactory.java:1570) 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.DefaultListableBeanFactory.preInstantiateSingletons ( defaultlistablebeanfactory.java:736) at Org.springframework.context.support.AbstractApplicationContext.finishBeanFactoryInitialization ( abstractapplicationcontext.java:757) at Org.springframework.context.support.AbstractApplicationContext.refresh ( abstractapplicationcontext.java:480) at Org.springframework.web.servlet.FrameworkServlet.configureAndRefreshWebApplicationContext ( frameworkservlet.java:664) at Org.springframework.web.servlet.FrameworkServlet.createWebApplicationContext ( frameworkservlet.java:630) at Org.springframework.web.servlet.FrameworkServlet.createWebApplicationContext ( frameworkservlet.java:678) at Org.springframework.web.servlet.FrameworkServlet.initWebApplicationContext ( frameworkservlet.java:549) at Org.springframework.web.servlet.FrameworkServlet.initServletBean (Frameworkservlet. java:490) at Org.springframework.web.servlet.HttpServletBean.init (httpservletbean.java:136) at Javax.servlet.GenericServlet.init (genericservlet.java:158) at Org.apache.catalina.core.StandardWrapper.initServlet (standardwrapper.java:1269) at Org.apache.catalina.core.StandardWrapper.loadServlet (standardwrapper.java:1182) at Org.apache.catalina.core.StandardWrapper.allocate (standardwrapper.java:853) at Org.apache.catalina.core.StandardWrapperValve.invoke (standardwrappervalve.java:134) at Org.apache.catalina.core.StandardContextValve.invoke (standardcontextvalve.java:110) at Org.apache.catalina.authenticator.AuthenticatorBase.invoke (authenticatorbase.java:506) at Org.apache.catalina.core.StandardHostValve.invoke (standardhostvalve.java:169) at Org.apache.catalina.valves.ErrorReportValve.invoke (errorreportvalve.java:103) at Org.apache.catalina.valves.AccessLogValve.invoke (accesslogvalve.java:962) at
Org.apache.catalina.core.StandardEngineValve.invoke (standardenginevalve.java:116)	At Org.apache.catalina.connector.CoyoteAdapter.service (coyoteadapter.java:445) at Org.apache.coyote.http11.AbstractHttp11Processor.process (abstracthttp11processor.java:1115) at Org.apache.coyote.abstractprotocol$abstractconnectionhandler.process (abstractprotocol.java:637) at Org.apache.tomcat.util.net.jioendpoint$socketprocessor.run (jioendpoint.java:316) at Java.util.concurrent.ThreadPoolExecutor.runWorker (threadpoolexecutor.java:1149) at Java.util.concurrent.threadpoolexecutor$worker.run (threadpoolexecutor.java:624) at Org.apache.tomcat.util.threads.taskthread$wrappingrunnable.run (taskthread.java:61) at Java.lang.Thread.run (
 thread.java:748)

The approximate presentation of the anomaly is as follows:

Java.lang.IllegalArgumentException:Result Maps Collection already contains value for XXX.XXX.XXX.BASERESULTMAP
It probably means that the result set already exists, it takes a lot of time to find out why, and finally, with Eclipse's global search, it does have duplicate baseresultmap in the same mapper file.
The reason for this problem is that when mapper is generated multiple times using MyBatis reverse engineering, the previously generated mapper.xml is not deleted, causing it to append content to the original XML. Eventually leads to baseresultmap repetition.
Workaround: Delete the generated mapper.xml and regenerate.