ssm 映射文件出錯

ssm 映射文件出錯

前言：今天做項目的時候發現了一個錯誤，也花費了不少時間去解決，爲避免以後在犯該錯,或者能快速定位與解決問題，特記之。

錯誤的日記如下：

嚴重: Servlet.service() for servlet [springmvc] in context with path [/myTicketManager] threw exception [Request processing failed; nested exception is org.apache.ibatis.binding.BindingException: Invalid bound statement (not found): com.sxt.dao.CustomersDaoMapper.findPageCustomers] with root cause
org.apache.ibatis.binding.BindingException: Invalid bound statement (not found): com.sxt.dao.CustomersDaoMapper.findPageCustomers
	at org.apache.ibatis.binding.MapperMethod$SqlCommand.<init>(MapperMethod.java:189)
	at org.apache.ibatis.binding.MapperMethod.<init>(MapperMethod.java:43)
	at org.apache.ibatis.binding.MapperProxy.cachedMapperMethod(MapperProxy.java:58)
	at org.apache.ibatis.binding.MapperProxy.invoke(MapperProxy.java:51)
	at com.sun.proxy.$Proxy13.findPageCustomers(Unknown Source)
	at com.sxt.service.impl.CustomerServiceImpl.findPageCustomers(CustomerServiceImpl.java:20)
	at com.sxt.controller.CustomerController.findCustomersWithPage(CustomerController.java:41)
	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:497)
	at org.springframework.web.method.support.InvocableHandlerMethod.invoke(InvocableHandlerMethod.java:215)
	at org.springframework.web.method.support.InvocableHandlerMethod.invokeForRequest(InvocableHandlerMethod.java:132)
	at org.springframework.web.servlet.mvc.method.annotation.ServletInvocableHandlerMethod.invokeAndHandle(ServletInvocableHandlerMethod.java:104)
	at org.springframework.web.servlet.mvc.method.annotation.RequestMappingHandlerAdapter.invokeHandleMethod(RequestMappingHandlerAdapter.java:745)
	at org.springframework.web.servlet.mvc.method.annotation.RequestMappingHandlerAdapter.handleInternal(RequestMappingHandlerAdapter.java:686)
	at org.springframework.web.servlet.mvc.method.AbstractHandlerMethodAdapter.handle(AbstractHandlerMethodAdapter.java:80)
	at org.springframework.web.servlet.DispatcherServlet.doDispatch(DispatcherServlet.java:925)
	at org.springframework.web.servlet.DispatcherServlet.doService(DispatcherServlet.java:856)
	at org.springframework.web.servlet.FrameworkServlet.processRequest(FrameworkServlet.java:953)
	at org.springframework.web.servlet.FrameworkServlet.doPost(FrameworkServlet.java:855)
	at javax.servlet.http.HttpServlet.service(HttpServlet.java:648)
	at org.springframework.web.servlet.FrameworkServlet.service(FrameworkServlet.java:829)
	at javax.servlet.http.HttpServlet.service(HttpServlet.java:729)
	at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:292)
	at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:207)
	at org.apache.tomcat.websocket.server.WsFilter.doFilter(WsFilter.java:52)
	at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:240)
	at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:207)
	at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:212)
	at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:106)
	at org.apache.catalina.authenticator.AuthenticatorBase.invoke(AuthenticatorBase.java:502)
	at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:141)
	at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:79)
	at org.apache.catalina.valves.AbstractAccessLogValve.invoke(AbstractAccessLogValve.java:616)
	at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:88)
	at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:522)
	at org.apache.coyote.http11.AbstractHttp11Processor.process(AbstractHttp11Processor.java:1095)
	at org.apache.coyote.AbstractProtocol$AbstractConnectionHandler.process(AbstractProtocol.java:672)
	at org.apache.tomcat.util.net.NioEndpoint$SocketProcessor.doRun(NioEndpoint.java:1502)
	at org.apache.tomcat.util.net.NioEndpoint$SocketProcessor.run(NioEndpoint.java:1458)
	at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1142)
	at java.util.concurrent.ThreadPoolExecutor$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)

其中關鍵信息是：

[Request processing failed; nested exception is org.apache.ibatis.binding.BindingException: Invalid bound statement (not found): com.sxt.dao.CustomersDaoMapper.findPageCustomers] with root cause
org.apache.ibatis.binding.BindingException: Invalid bound statement (not found): com.sxt.dao.CustomersDaoMapper.findPageCustomers

意思是非法綁定錯誤，無法找到配置文件！！！！！

我反覆檢查了我的目錄結構，配置文件明明存在，且名字也沒寫錯，最後才發現錯誤出處！

總結：發生該錯誤有以下兩種情況

一.映射文件名要與dao層名一樣，如（UserDaoMapper.java  與 UserDaoMapper.xml）

二.映射文件裏的方法id名需和Dao層裏的方法名一致，一 一對應

最後：與其花編碼的兩倍時間去查改錯誤，不如在編碼之初就細心將其規避！！！