解决idea创建ssm项目找不到mybatis的mapper的xml文件问题

之前搞了有一年多的大数据，web好多东西有点忘记了，最近准备重新看一下，自己用idea建了个项目试试，碰到个问题，后来仔细想了下找到了解决办法，这里记录一下。

创建一个maven web工程，项目结构如下

就是想实现一个简单的查询功能，把spring mvc、spring 和 mybatis整合起来。

部署并启动项目后，总是报一个错误：org.apache.ibatis.binding.BindingException: Invalid bound statement (not found)

09-Apr-2017 17:42:20.864 严重 [http-nio-8080-exec-4] org.apache.catalina.core.StandardWrapperValve.invoke Servlet.service() for servlet [dispatcherServlet] in context with path [] threw exception [Request processing failed; nested exception is org.apache.ibatis.binding.BindingException: Invalid bound statement (not found): com.runtu.dao.UserMapper.selectUserById] with root cause
 org.apache.ibatis.binding.BindingException: Invalid bound statement (not found): com.runtu.dao.UserMapper.selectUserById
	at org.apache.ibatis.binding.MapperMethod$SqlCommand.(MapperMethod.java:189)
	at org.apache.ibatis.binding.MapperMethod.(MapperMethod.java:43)
	at org.apache.ibatis.binding.MapperProxy.cachedMapperMethod(MapperProxy.java:58)
	at org.apache.ibatis.binding.MapperProxy.invoke(MapperProxy.java:51)
	at com.sun.proxy.$Proxy17.selectUserById(Unknown Source)
	at com.runtu.service.UserService.selectUserById(UserService.java:17)
	at com.runtu.controller.UserController.getIndex(UserController.java:23)
	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.web.bind.annotation.support.HandlerMethodInvoker.invokeHandlerMethod(HandlerMethodInvoker.java:178)
	at org.springframework.web.servlet.mvc.annotation.AnnotationMethodHandlerAdapter.invokeHandlerMethod(AnnotationMethodHandlerAdapter.java:444)
	at org.springframework.web.servlet.mvc.annotation.AnnotationMethodHandlerAdapter.handle(AnnotationMethodHandlerAdapter.java:432)
	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:968)
	at org.springframework.web.servlet.FrameworkServlet.doGet(FrameworkServlet.java:859)
	at javax.servlet.http.HttpServlet.service(HttpServlet.java:622)
	at org.springframework.web.servlet.FrameworkServlet.service(FrameworkServlet.java:844)
	at javax.servlet.http.HttpServlet.service(HttpServlet.java:729)
	at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:230)
	at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:165)
	at org.apache.tomcat.websocket.server.WsFilter.doFilter(WsFilter.java:53)
	at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:192)
	at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:165)
	at org.springframework.web.filter.CharacterEncodingFilter.doFilterInternal(CharacterEncodingFilter.java:121)
	at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:107)
	at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:192)
	at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:165)
	at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:199)
	at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:96)
	at org.apache.catalina.authenticator.AuthenticatorBase.invoke(AuthenticatorBase.java:474)
	at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:140)
	at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:79)
	at org.apache.catalina.valves.AbstractAccessLogValve.invoke(AbstractAccessLogValve.java:624)
	at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:87)
	at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:349)
	at org.apache.coyote.http11.Http11Processor.service(Http11Processor.java:495)
	at org.apache.coyote.AbstractProcessorLight.process(AbstractProcessorLight.java:66)
	at org.apache.coyote.AbstractProtocol$ConnectionHandler.process(AbstractProtocol.java:767)
	at org.apache.tomcat.util.net.NioEndpoint$SocketProcessor.doRun(NioEndpoint.java:1347)
	at org.apache.tomcat.util.net.SocketProcessorBase.run(SocketProcessorBase.java:49)
	at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1142)
	at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:617)
	at org.apache.tomcat.util.threads.TaskThread$WrappingRunnable.run(TaskThread.java:61)
	at java.lang.Thread.run(Thread.java:745)

我估计是没找到xml文件，但是我记得之前在eclipse中好像配置完没这个问题，打开编译后的文件目录查看下mapper对应xml文件确实是不在里面

后来上网搜了下，别人给出的答复

idea在build工程的时候 遇到maven项目 使用的是pom文件里面配置的里面的东西
而这里面如果不做特别配置 是maven默认的 编译的时候 只搬运src/main/java里面的java文件到target/classes,其他文件会被忽略
解决办法就是向maven-resources-plugin插件增加配置 
http://bbs.csdn.net/topics/391841282?page=1#post-402070612 这个里面有配置的全文
这样配置之后 idea在build的时候 或者执行 maven test 的时候 才能把源码文件夹里的xml文件与java文件一起搬到target/classes 里面去 
别人如果导入你的这个maven工程 也不用设置idea了

另外 为什么在eclipse里面 即使pom不做这个特别配置 也没问题 原因是eclipse在build工程的时候 不依赖 maven的pom文件 用的eclipse的编译机制 不会忽略源码文件夹里面的xml文件

按照这个修改下增加了个插件，再重新编译部署下，发现好了

            
                maven-resources-plugin
                2.6
                
                    
                        copy-xmls
                        process-resources
                        
                            copy-resources
                        
                        
                            ${basedir}/target/classes
                            
                                
                                    ${basedir}/src/main/java
                                    
                                        **/*.xml
                                    
                                
                            
                        
                    
                
            

至此问题解决了。