解决报错：IncompleteElementException: Could not find result map...

org.apache.ibatis.builder.IncompleteElementException: Could not find result map com.xxx.manager.mapper.ItemMapper.Item

    at org.apache.ibatis.builder.MapperBuilderAssistant.getStatementResultMaps(MapperBuilderAssistant.java:346)
    at org.apache.ibatis.builder.MapperBuilderAssistant.addMappedStatement(MapperBuilderAssistant.java:290)
    at org.apache.ibatis.builder.xml.XMLStatementBuilder.parseStatementNode(XMLStatementBuilder.java:109)
    at org.apache.ibatis.session.Configuration.buildAllStatements(Configuration.java:788)
    at org.apache.ibatis.session.Configuration.hasStatement(Configuration.java:758)
    at org.apache.ibatis.session.Configuration.hasStatement(Configuration.java:753)
    at org.apache.ibatis.binding.MapperMethod$SqlCommand.resolveMappedStatement(MapperMethod.java:247)
    at org.apache.ibatis.binding.MapperMethod$SqlCommand.<init>(MapperMethod.java:217)
    at org.apache.ibatis.binding.MapperMethod.<init>(MapperMethod.java:48)
    at org.apache.ibatis.binding.MapperProxy.cachedMapperMethod(MapperProxy.java:65)
    at org.apache.ibatis.binding.MapperProxy.invoke(MapperProxy.java:58)
    at com.sun.proxy.$Proxy22.select(Unknown Source)
    at com.xxxx.manager.service.impl.BaseServiceImpl.getList(BaseServiceImpl.java:97)
    at com.xxxx.manager.service.impl.BaseServiceImpl$$FastClassBySpringCGLIB$$dae8e2b1.invoke(<generated>)
    at org.springframework.cglib.proxy.MethodProxy.invoke(MethodProxy.java:204)
    at org.springframework.aop.framework.CglibAopProxy$CglibMethodInvocation.invokeJoinpoint(CglibAopProxy.java:738)
    at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:157)
    at org.springframework.transaction.interceptor.TransactionInterceptor$1.proceedWithInvocation(TransactionInterceptor.java:99)
    at org.springframework.transaction.interceptor.TransactionAspectSupport.invokeWithinTransaction(TransactionAspectSupport.java:282)
    at org.springframework.transaction.interceptor.TransactionInterceptor.invoke(TransactionInterceptor.java:96)
    at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:179)
    at org.springframework.aop.interceptor.ExposeInvocationInterceptor.invoke(ExposeInvocationInterceptor.java:92)
    at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:179)
    at org.springframework.aop.framework.CglibAopProxy$DynamicAdvisedInterceptor.intercept(CglibAopProxy.java:673)
    at com.xxxx.manager.service.impl.ItemServiceImpl$$EnhancerBySpringCGLIB$$5180168e.getList(<generated>)
    at com.xxxx.manager.TestMybaitsMapper.testGetList(TestMybaitsMapper.java:30)
    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.junit.runners.model.FrameworkMethod$1.runReflectiveCall(FrameworkMethod.java:50)
    at org.junit.internal.runners.model.ReflectiveCallable.run(ReflectiveCallable.java:12)
    at org.junit.runners.model.FrameworkMethod.invokeExplosively(FrameworkMethod.java:47)
    at org.junit.internal.runners.statements.InvokeMethod.evaluate(InvokeMethod.java:17)
    at org.junit.internal.runners.statements.RunBefores.evaluate(RunBefores.java:26)
    at org.junit.runners.ParentRunner.runLeaf(ParentRunner.java:325)
    at org.junit.runners.BlockJUnit4ClassRunner.runChild(BlockJUnit4ClassRunner.java:78)
    at org.junit.runners.BlockJUnit4ClassRunner.runChild(BlockJUnit4ClassRunner.java:57)
    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$2.evaluate(ParentRunner.java:268)
    at org.junit.runners.ParentRunner.run(ParentRunner.java:363)
    at org.junit.runner.JUnitCore.run(JUnitCore.java:137)
    at com.intellij.junit4.JUnit4IdeaTestRunner.startRunnerWithArgs(JUnit4IdeaTestRunner.java:68)
    at com.intellij.rt.execution.junit.IdeaTestRunner$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: java.lang.IllegalArgumentException: Result Maps collection does not contain value for com.xxxx.manager.mapper.ItemMapper.Item
    at org.apache.ibatis.session.Configuration$StrictMap.get(Configuration.java:888)
    at org.apache.ibatis.session.Configuration.getResultMap(Configuration.java:640)
    at org.apache.ibatis.builder.MapperBuilderAssistant.getStatementResultMaps(MapperBuilderAssistant.java:344)
    ... 48 more