同事让我帮他找一个错误，他说明明写的对的，怎么老是报错。其实，使用MyBaties在编写sql配置文件时，都会遇到的一个小问题，问题虽小，对初学者可能都会碰到。
org.apache.ibatis.builder.IncompleteElementException: Could not find parameter map com.boco.fsmsys.amuse.dao.AmuseItemDao.amuseItem
at org.apache.ibatis.builder.MapperBuilderAssistant.setStatementParameterMap(MapperBuilderAssistant.java:326)
at org.apache.ibatis.builder.MapperBuilderAssistant.addMappedStatement(MapperBuilderAssistant.java:290)
at org.apache.ibatis.builder.xml.XMLStatementBuilder.parseStatementNode(XMLStatementBuilder.java:110)
at org.apache.ibatis.session.Configuration.buildAllStatements(Configuration.java:567)
at org.apache.ibatis.session.Configuration.getMappedStatement(Configuration.java:493)
at org.apache.ibatis.session.Configuration.getMappedStatement(Configuration.java:488)
at org.apache.ibatis.binding.MapperMethod.setupCommandType(MapperMethod.java:236)
at org.apache.ibatis.binding.MapperMethod.<init>(MapperMethod.java:71)
at org.apache.ibatis.binding.MapperProxy.invoke(MapperProxy.java:39)
at $Proxy9.find(Unknown Source)
at com.boco.fsmsys.amuse.service.impl.AmuseItemServiceImpl.find(AmuseItemServiceImpl.java:31)
at com.boco.fsmsys.amuse.service.impl.AmuseItemServiceImpl$$FastClassByCGLIB$$f42525b0.invoke(<generated>)
at net.sf.cglib.proxy.MethodProxy.invoke(MethodProxy.java:149)
at org.springframework.aop.framework.Cglib2AopProxy$CglibMethodInvocation.invokeJoinpoint(Cglib2AopProxy.java:689)
at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:150)
at org.springframework.transaction.interceptor.TransactionInterceptor.invoke(TransactionInterceptor.java:110)
at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:172)
at org.springframework.aop.interceptor.ExposeInvocationInterceptor.invoke(ExposeInvocationInterceptor.java:90)
at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:172)
at org.springframework.aop.framework.Cglib2AopProxy$DynamicAdvisedInterceptor.intercept(Cglib2AopProxy.java:622)
at com.boco.fsmsys.amuse.service.impl.AmuseItemServiceImpl$$EnhancerByCGLIB$$b6a4972c.find(<generated>)
at com.boco.fsmsys.test.service.AmuseItemServiceTest.testFind(AmuseItemServiceTest.java:15)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:39)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:25)
at java.lang.reflect.Method.invoke(Method.java:597)
at org.junit.runners.model.FrameworkMethod$1.runReflectiveCall(FrameworkMethod.java:44)
at org.junit.internal.runners.model.ReflectiveCallable.run(ReflectiveCallable.java:15)
at org.junit.runners.model.FrameworkMethod.invokeExplosively(FrameworkMethod.java:41)
at org.junit.internal.runners.statements.InvokeMethod.evaluate(InvokeMethod.java:20)
at org.junit.internal.runners.statements.RunBefores.evaluate(RunBefores.java:28)
at org.junit.internal.runners.statements.RunAfters.evaluate(RunAfters.java:31)
at org.junit.runners.BlockJUnit4ClassRunner.runChild(BlockJUnit4ClassRunner.java:73)
at org.junit.runners.BlockJUnit4ClassRunner.runChild(BlockJUnit4ClassRunner.java:46)
at org.junit.runners.ParentRunner.runChildren(ParentRunner.java:180)
at org.junit.runners.ParentRunner.access$000(ParentRunner.java:41)
at org.junit.runners.ParentRunner$1.evaluate(ParentRunner.java:173)
at org.junit.internal.runners.statements.RunBefores.evaluate(RunBefores.java:28)
at org.junit.internal.runners.statements.RunAfters.evaluate(RunAfters.java:31)
at org.junit.runners.ParentRunner.run(ParentRunner.java:220)
at org.eclipse.jdt.internal.junit4.runner.JUnit4TestReference.run(JUnit4TestReference.java:46)
at org.eclipse.jdt.internal.junit.runner.TestExecution.run(TestExecution.java:38)
at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.runTests(RemoteTestRunner.java:467)
at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.runTests(RemoteTestRunner.java:683)
at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.run(RemoteTestRunner.java:390)
at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.main(RemoteTestRunner.java:197)
Caused by: java.lang.IllegalArgumentException: Parameter Maps collection does not contain value for com.boco.fsmsys.amuse.dao.AmuseItemDao.amuseItem
at org.apache.ibatis.session.Configuration$StrictMap.get(Configuration.java:660)
at org.apache.ibatis.session.Configuration.getParameterMap(Configuration.java:442)
at org.apache.ibatis.builder.MapperBuilderAssistant.setStatementParameterMap(MapperBuilderAssistant.java:324)
... 45 more
从异常的提示发现是配置文件中，find这个方法的sql参数类型或者名称写错了，但是你发现这个位置并没有些写错。于是你很困惑，其实问题就在这个配置文件中，提示的也对，只是位置不对。mybaties中只要有任何一个地方报错，都无法通过。最后发现是另个一个方法上将parameterType写成了parameterMap了（
- <select id="getClassByID" parameterMap="String" resultMap="classResultMap">
）。
再者之所以大家犯错，有一个原因是在编写配置文件时，会提示parameterMap ，但是这个在mybaties中已经不再用这个属性了。所以大家写配置文件时，要小心细心。