org.apache.ibatis.binding.BindingException: Invalid bound statement (not found)

在Maven项目中使用mybatis逆向工程生成的Mapper，在查询数据库时，报出一下异常：

org.apache.ibatis.binding.BindingException: Invalid bound statement (not found): com.devin.mapper.UserMapper.countByExample
at org.apache.ibatis.binding.MapperMethod$SqlCommand.<init>(MapperMethod.java:189)
at org.apache.ibatis.binding.MapperMethod.<init>(MapperMethod.java:43)
at org.apache.ibatis.binding.MapperProxy.cachedMapperMethod(MapperProxy.java:58)
at org.apache.ibatis.binding.MapperProxy.invoke(MapperProxy.java:51)
at com.sun.proxy.$Proxy31.countByExample(Unknown Source)
at com.devin.service.UserService.hasMatchUser(UserService.java:41)
at com.devin.service.UserService$$FastClassBySpringCGLIB$$e621ac70.invoke(<generated>)
at org.springframework.cglib.proxy.MethodProxy.invoke(MethodProxy.java:204)
at org.springframework.aop.framework.CglibAopProxy$CglibMethodInvocation.invokeJoinpoint(CglibAopProxy.java:720)
at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:157)
at org.springframework.aop.interceptor.ExposeInvocationInterceptor.invoke(ExposeInvocationInterceptor.java:92)
at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:179)
at org.springframework.aop.framework.CglibAopProxy$DynamicAdvisedInterceptor.intercept(CglibAopProxy.java:655)
at com.devin.service.UserService$$EnhancerBySpringCGLIB$$65214723.hasMatchUser(<generated>)
at com.devin.controller.LoginController.loginCheck(LoginController.java:30)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:57)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
at java.lang.reflect.Method.invoke(Method.java:606)
at org.springframework.web.method.support.InvocableHandlerMethod.doInvoke(InvocableHandlerMethod.java:222)
at org.springframework.web.method.support.InvocableHandlerMethod.invokeForRequest(InvocableHandlerMethod.java:137)
at org.springframework.web.servlet.mvc.method.annotation.ServletInvocableHandlerMethod.invokeAndHandle(ServletInvocableHandlerMethod.java:110)
at org.springframework.web.servlet.mvc.method.annotation.RequestMappingHandlerAdapter.invokeHandlerMethod(RequestMappingHandlerAdapter.java:814)
at org.springframework.web.servlet.mvc.method.annotation.RequestMappingHandlerAdapter.handleInternal(RequestMappingHandlerAdapter.java:737)
at org.springframework.web.servlet.mvc.method.AbstractHandlerMethodAdapter.handle(AbstractHandlerMethodAdapter.java:85)
at org.springframework.web.servlet.DispatcherServlet.doDispatch(DispatcherServlet.java:959)
at org.springframework.web.servlet.DispatcherServlet.doService(DispatcherServlet.java:893)
at org.springframework.web.servlet.FrameworkServlet.processRequest(FrameworkServlet.java:969)
at org.springframework.web.servlet.FrameworkServlet.doPost(FrameworkServlet.java:871)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:647)
at org.springframework.web.servlet.FrameworkServlet.service(FrameworkServlet.java:845)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:728)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:305)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:210)
at org.apache.tomcat.websocket.server.WsFilter.doFilter(WsFilter.java:51)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:243)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:210)
at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:222)
at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:123)
at org.apache.catalina.authenticator.AuthenticatorBase.invoke(AuthenticatorBase.java:502)
at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:171)
at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:100)
at org.apache.catalina.valves.AccessLogValve.invoke(AccessLogValve.java:953)
at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:118)
at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:408)
at org.apache.coyote.http11.AbstractHttp11Processor.process(AbstractHttp11Processor.java:1041)
at org.apache.coyote.AbstractProtocol$AbstractConnectionHandler.process(AbstractProtocol.java:603)
at org.apache.tomcat.util.net.JIoEndpoint$SocketProcessor.run(JIoEndpoint.java:310)
at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1145)
at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:615)
at java.lang.Thread.run(Thread.java:745)

看异常信息像是Mapper interface和xml文件的定义对应不上，可是这些是逆向工程自动生成的，应该是不会有这些问题啊，还是检查了一下包名，namespace，函数名称等等，果然没有问题。

于是去classes文件夹中查找是否有xml文件，发现没有，但是其他的xml文件都会自动复制到classes文件夹中，比较了一下区别，其他文件是放在resource文件夹中，但是mapper.xml文件是放在Java文件夹中的，在Java文件夹下，.java文件会被编译成.class文件，但是这个是个xml文件，应该不会被编译，即使被编译也肯定不会生成什么字节码啊，而Java文件夹也不会复制其文件夹下的.java文件到classes文件夹中，所以xml文件放在java文件夹中是
bdd1
不会被复制到classes文件夹中，那么解决办法就是将其放到resource文件夹中了。

如图所示：



但是这样做的话，还需要配置mybatis的sqlMapConfig.xml配置文件：

<mappers>
<!-- resouce方法加载单个映射文件 -->
<mapper resource="mapper/UserMapper.xml"/>
<mapper resource="mapper/LoginLogMapper.xml"/>
</mappers>

如果就想把mapper.xml放在Java文件夹中呢？

可以通过pom.xml文件中配置：

<resource>
<directory>src/main/java</directory>
<includes>
<include>**/*.xml</include>
</includes>
</resource>

重新编译项目，又发生以下异常：

Caused by: java.io.FileNotFoundException: class path resource [spring/] cannot be resolved to URL because it does not exist

打开本地的文件夹，发现原本在resource文件夹中的文件不会被复制到classes文件夹中了，但是java文件夹中mapper.xml文件夹被复制到classes文件夹中了，于是重新修改配置：

        <resources>
<resource>
<directory>src/main/java</directory>
<includes>
<include>**/*.xml</include>
</includes>
</resource>

<resource>
<directory>src/main/resources</directory>
<includes>
<!-- 不能是**/*.xml，因为目录中有*.properties文件 -->
<include>**/*</include>
</includes>
</resource>
</resources>

重新编译项目，也解决了问题。