SpringBoot報錯：Failed to load ApplicationContext(Mapped Statements collection already contains value)

錯誤提示：
Caused by: java.lang.IllegalArgumentException: Mapped Statements collection already contains value for com.tuyrk._161_java_socket.project6.dao.UserMapper.findOne
錯誤緣由：
在Mybatis的配置文件中，配置了重名的方法findOne。
解決方法：
將方法名稱改爲其餘名稱。Mybatis配置文件不能重名。

java.lang.IllegalStateException: Failed to load ApplicationContext
    at org.springframework.test.context.cache.DefaultCacheAwareContextLoaderDelegate.loadContext(DefaultCacheAwareContextLoaderDelegate.java:125)
    at org.springframework.test.context.support.DefaultTestContext.getApplicationContext(DefaultTestContext.java:108)
    at org.springframework.test.context.support.DependencyInjectionTestExecutionListener.injectDependencies(DependencyInjectionTestExecutionListener.java:118)
    at org.springframework.test.context.support.DependencyInjectionTestExecutionListener.prepareTestInstance(DependencyInjectionTestExecutionListener.java:83)
    at org.springframework.boot.test.autoconfigure.SpringBootDependencyInjectionTestExecutionListener.prepareTestInstance(SpringBootDependencyInjectionTestExecutionListener.java:44)
    at org.springframework.test.context.TestContextManager.prepareTestInstance(TestContextManager.java:246)
    at org.springframework.test.context.junit4.SpringJUnit4ClassRunner.createTest(SpringJUnit4ClassRunner.java:227)
    at org.springframework.test.context.junit4.SpringJUnit4ClassRunner$1.runReflectiveCall(SpringJUnit4ClassRunner.java:289)
    at org.junit.internal.runners.model.ReflectiveCallable.run(ReflectiveCallable.java:12)
    at org.springframework.test.context.junit4.SpringJUnit4ClassRunner.methodBlock(SpringJUnit4ClassRunner.java:291)
    at org.springframework.test.context.junit4.SpringJUnit4ClassRunner.runChild(SpringJUnit4ClassRunner.java:246)
    at org.springframework.test.context.junit4.SpringJUnit4ClassRunner.runChild(SpringJUnit4ClassRunner.java:97)
    at org.junit.runners.ParentRunner$3.run(ParentRunner.java:290)
    at org.junit.runners.ParentRunner$1.schedule(ParentRunner.java:71)
    at org.junit.runners.ParentRunner.runChildren(ParentRunner.java:288)
    at org.junit.runners.ParentRunner.access$000(ParentRunner.java:58)
    at org.junit.runners.ParentRunner$2.evaluate(ParentRunner.java:268)
    at org.springframework.test.context.junit4.statements.RunBeforeTestClassCallbacks.evaluate(RunBeforeTestClassCallbacks.java:61)
    at org.springframework.test.context.junit4.statements.RunAfterTestClassCallbacks.evaluate(RunAfterTestClassCallbacks.java:70)
    at org.junit.runners.ParentRunner.run(ParentRunner.java:363)
    at org.springframework.test.context.junit4.SpringJUnit4ClassRunner.run(SpringJUnit4ClassRunner.java:190)
    at org.junit.runner.JUnitCore.run(JUnitCore.java:137)
    at com.intellij.junit4.JUnit4IdeaTestRunner.startRunnerWithArgs(JUnit4IdeaTestRunner.java:68)
    at com.intellij.rt.execution.junit.IdeaTestRunner$Repeater.startRunnerWithArgs(IdeaTestRunner.java:47)
    at com.intellij.rt.execution.junit.JUnitStarter.prepareStreamsAndStart(JUnitStarter.java:242)
    at com.intellij.rt.execution.junit.JUnitStarter.main(JUnitStarter.java:70)
Caused by: org.springframework.beans.factory.UnsatisfiedDependencyException: Error creating bean with name 'fileServiceImpl': Unsatisfied dependency expressed through field 'fileMapper'; nested exception is org.springframework.beans.factory.UnsatisfiedDependencyException: Error creating bean with name 'fileMapper' defined in file [E:\java\learn-imooc\161-java-socket\target\classes\com\tuyrk\_161_java_socket\project6\dao\FileMapper.class]: Unsatisfied dependency expressed through bean property 'sqlSessionFactory'; nested exception is org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'sqlSessionFactory' defined in class path resource [org/mybatis/spring/boot/autoconfigure/MybatisAutoConfiguration.class]: Bean instantiation via factory method failed; nested exception is org.springframework.beans.BeanInstantiationException: Failed to instantiate [org.apache.ibatis.session.SqlSessionFactory]: Factory method 'sqlSessionFactory' threw exception; nested exception is org.springframework.core.NestedIOException: Failed to parse mapping resource: 'file [E:\java\learn-imooc\161-java-socket\target\classes\mybatis\UserMapper.xml]'; nested exception is org.apache.ibatis.builder.BuilderException: Error parsing Mapper XML. The XML location is 'file [E:\java\learn-imooc\161-java-socket\target\classes\mybatis\UserMapper.xml]'. Cause: java.lang.IllegalArgumentException: Mapped Statements collection already contains value for com.tuyrk._161_java_socket.project6.dao.UserMapper.findOne
    at org.springframework.beans.factory.annotation.AutowiredAnnotationBeanPostProcessor$AutowiredFieldElement.inject(AutowiredAnnotationBeanPostProcessor.java:596)
    at org.springframework.beans.factory.annotation.InjectionMetadata.inject(InjectionMetadata.java:90)
    at org.springframework.beans.factory.annotation.AutowiredAnnotationBeanPostProcessor.postProcessProperties(AutowiredAnnotationBeanPostProcessor.java:374)
    at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.populateBean(AbstractAutowireCapableBeanFactory.java:1378)
    at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.doCreateBean(AbstractAutowireCapableBeanFactory.java:575)
    at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBean(AbstractAutowireCapableBeanFactory.java:498)
    at org.springframework.beans.factory.support.AbstractBeanFactory.lambda$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:846)
    at org.springframework.context.support.AbstractApplicationContext.finishBeanFactoryInitialization(AbstractApplicationContext.java:863)
    at org.springframework.context.support.AbstractApplicationContext.refresh(AbstractApplicationContext.java:546)
    at org.springframework.boot.SpringApplication.refresh(SpringApplication.java:775)
    at org.springframework.boot.SpringApplication.refreshContext(SpringApplication.java:397)
    at org.springframework.boot.SpringApplication.run(SpringApplication.java:316)
    at org.springframework.boot.test.context.SpringBootContextLoader.loadContext(SpringBootContextLoader.java:127)
    at org.springframework.test.context.cache.DefaultCacheAwareContextLoaderDelegate.loadContextInternal(DefaultCacheAwareContextLoaderDelegate.java:99)
    at org.springframework.test.context.cache.DefaultCacheAwareContextLoaderDelegate.loadContext(DefaultCacheAwareContextLoaderDelegate.java:117)
    ... 25 more
Caused by: org.springframework.beans.factory.UnsatisfiedDependencyException: Error creating bean with name 'fileMapper' defined in file [E:\java\learn-imooc\161-java-socket\target\classes\com\tuyrk\_161_java_socket\project6\dao\FileMapper.class]: Unsatisfied dependency expressed through bean property 'sqlSessionFactory'; nested exception is org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'sqlSessionFactory' defined in class path resource [org/mybatis/spring/boot/autoconfigure/MybatisAutoConfiguration.class]: Bean instantiation via factory method failed; nested exception is org.springframework.beans.BeanInstantiationException: Failed to instantiate [org.apache.ibatis.session.SqlSessionFactory]: Factory method 'sqlSessionFactory' threw exception; nested exception is org.springframework.core.NestedIOException: Failed to parse mapping resource: 'file [E:\java\learn-imooc\161-java-socket\target\classes\mybatis\UserMapper.xml]'; nested exception is org.apache.ibatis.builder.BuilderException: Error parsing Mapper XML. The XML location is 'file [E:\java\learn-imooc\161-java-socket\target\classes\mybatis\UserMapper.xml]'. Cause: java.lang.IllegalArgumentException: Mapped Statements collection already contains value for com.tuyrk._161_java_socket.project6.dao.UserMapper.findOne
    at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.autowireByType(AbstractAutowireCapableBeanFactory.java:1482)
    at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.populateBean(AbstractAutowireCapableBeanFactory.java:1362)
    at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.doCreateBean(AbstractAutowireCapableBeanFactory.java:575)
    at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBean(AbstractAutowireCapableBeanFactory.java:498)
    at org.springframework.beans.factory.support.AbstractBeanFactory.lambda$doGetBean$0(AbstractBeanFactory.java:320)
    at org.springframework.beans.factory.support.DefaultSingletonBeanRegistry.getSingleton(DefaultSingletonBeanRegistry.java:222)
    at org.springframework.beans.factory.support.AbstractBeanFactory.doGetBean(AbstractBeanFactory.java:318)
    at org.springframework.beans.factory.support.AbstractBeanFactory.getBean(AbstractBeanFactory.java:199)
    at org.springframework.beans.factory.config.DependencyDescriptor.resolveCandidate(DependencyDescriptor.java:273)
    at org.springframework.beans.factory.support.DefaultListableBeanFactory.doResolveDependency(DefaultListableBeanFactory.java:1237)
    at org.springframework.beans.factory.support.DefaultListableBeanFactory.resolveDependency(DefaultListableBeanFactory.java:1164)
    at org.springframework.beans.factory.annotation.AutowiredAnnotationBeanPostProcessor$AutowiredFieldElement.inject(AutowiredAnnotationBeanPostProcessor.java:593)
    ... 43 more
Caused by: org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'sqlSessionFactory' defined in class path resource [org/mybatis/spring/boot/autoconfigure/MybatisAutoConfiguration.class]: Bean instantiation via factory method failed; nested exception is org.springframework.beans.BeanInstantiationException: Failed to instantiate [org.apache.ibatis.session.SqlSessionFactory]: Factory method 'sqlSessionFactory' threw exception; nested exception is org.springframework.core.NestedIOException: Failed to parse mapping resource: 'file [E:\java\learn-imooc\161-java-socket\target\classes\mybatis\UserMapper.xml]'; nested exception is org.apache.ibatis.builder.BuilderException: Error parsing Mapper XML. The XML location is 'file [E:\java\learn-imooc\161-java-socket\target\classes\mybatis\UserMapper.xml]'. Cause: java.lang.IllegalArgumentException: Mapped Statements collection already contains value for com.tuyrk._161_java_socket.project6.dao.UserMapper.findOne
    at org.springframework.beans.factory.support.ConstructorResolver.instantiate(ConstructorResolver.java:627)
    at org.springframework.beans.factory.support.ConstructorResolver.instantiateUsingFactoryMethod(ConstructorResolver.java:607)
    at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.instantiateUsingFactoryMethod(AbstractAutowireCapableBeanFactory.java:1288)
    at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBeanInstance(AbstractAutowireCapableBeanFactory.java:1127)
    at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.doCreateBean(AbstractAutowireCapableBeanFactory.java:538)
    at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBean(AbstractAutowireCapableBeanFactory.java:498)
    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.config.DependencyDescriptor.resolveCandidate(DependencyDescriptor.java:273)
    at org.springframework.beans.factory.support.DefaultListableBeanFactory.doResolveDependency(DefaultListableBeanFactory.java:1237)
    at org.springframework.beans.factory.support.DefaultListableBeanFactory.resolveDependency(DefaultListableBeanFactory.java:1164)
    at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.autowireByType(AbstractAutowireCapableBeanFactory.java:1467)
    ... 54 more
Caused by: org.springframework.beans.BeanInstantiationException: Failed to instantiate [org.apache.ibatis.session.SqlSessionFactory]: Factory method 'sqlSessionFactory' threw exception; nested exception is org.springframework.core.NestedIOException: Failed to parse mapping resource: 'file [E:\java\learn-imooc\161-java-socket\target\classes\mybatis\UserMapper.xml]'; nested exception is org.apache.ibatis.builder.BuilderException: Error parsing Mapper XML. The XML location is 'file [E:\java\learn-imooc\161-java-socket\target\classes\mybatis\UserMapper.xml]'. Cause: java.lang.IllegalArgumentException: Mapped Statements collection already contains value for com.tuyrk._161_java_socket.project6.dao.UserMapper.findOne
    at org.springframework.beans.factory.support.SimpleInstantiationStrategy.instantiate(SimpleInstantiationStrategy.java:185)
    at org.springframework.beans.factory.support.ConstructorResolver.instantiate(ConstructorResolver.java:622)
    ... 67 more
Caused by: org.springframework.core.NestedIOException: Failed to parse mapping resource: 'file [E:\java\learn-imooc\161-java-socket\target\classes\mybatis\UserMapper.xml]'; nested exception is org.apache.ibatis.builder.BuilderException: Error parsing Mapper XML. The XML location is 'file [E:\java\learn-imooc\161-java-socket\target\classes\mybatis\UserMapper.xml]'. Cause: java.lang.IllegalArgumentException: Mapped Statements collection already contains value for com.tuyrk._161_java_socket.project6.dao.UserMapper.findOne
    at org.mybatis.spring.SqlSessionFactoryBean.buildSqlSessionFactory(SqlSessionFactoryBean.java:523)
    at org.mybatis.spring.SqlSessionFactoryBean.afterPropertiesSet(SqlSessionFactoryBean.java:380)
    at org.mybatis.spring.SqlSessionFactoryBean.getObject(SqlSessionFactoryBean.java:547)
    at org.mybatis.spring.boot.autoconfigure.MybatisAutoConfiguration.sqlSessionFactory(MybatisAutoConfiguration.java:153)
    at org.mybatis.spring.boot.autoconfigure.MybatisAutoConfiguration$$EnhancerBySpringCGLIB$$fcc430c7.CGLIB$sqlSessionFactory$0(<generated>)
    at org.mybatis.spring.boot.autoconfigure.MybatisAutoConfiguration$$EnhancerBySpringCGLIB$$fcc430c7$$FastClassBySpringCGLIB$$53907c2d.invoke(<generated>)
    at org.springframework.cglib.proxy.MethodProxy.invokeSuper(MethodProxy.java:244)
    at org.springframework.context.annotation.ConfigurationClassEnhancer$BeanMethodInterceptor.intercept(ConfigurationClassEnhancer.java:363)
    at org.mybatis.spring.boot.autoconfigure.MybatisAutoConfiguration$$EnhancerBySpringCGLIB$$fcc430c7.sqlSessionFactory(<generated>)
    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.springframework.beans.factory.support.SimpleInstantiationStrategy.instantiate(SimpleInstantiationStrategy.java:154)
    ... 68 more
Caused by: org.apache.ibatis.builder.BuilderException: Error parsing Mapper XML. The XML location is 'file [E:\java\learn-imooc\161-java-socket\target\classes\mybatis\UserMapper.xml]'. Cause: java.lang.IllegalArgumentException: Mapped Statements collection already contains value for com.tuyrk._161_java_socket.project6.dao.UserMapper.findOne
    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:521)
    ... 81 more
Caused by: java.lang.IllegalArgumentException: Mapped Statements collection already contains value for com.tuyrk._161_java_socket.project6.dao.UserMapper.findOne
    at org.apache.ibatis.session.Configuration$StrictMap.put(Configuration.java:872)
    at org.apache.ibatis.session.Configuration$StrictMap.put(Configuration.java:844)
    at org.apache.ibatis.session.Configuration.addMappedStatement(Configuration.java:668)
    at org.apache.ibatis.builder.MapperBuilderAssistant.addMappedStatement(MapperBuilderAssistant.java:302)
    at org.apache.ibatis.builder.xml.XMLStatementBuilder.parseStatementNode(XMLStatementBuilder.java:109)
    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)
    ... 83 more