Mybatis使用Bug日常（0001）
org.ibatis.binding.BindingException: Invalid bound statement (not found): com.xx.xx.XXMapper.listForPage
这是 Mybatis 使用过程中很常见的一个问题
一般来说,就是找不到Mapper映射, 下面我列举日常开发中最大可能出现的两种场景， 之所以是两种情况，是因为有个错误认知，下面已列举，大佬勿喷
错误认知：
- 日常开发或者教学(学校、培训老师)的时候，我们都是同名映射文件(也就是java文件和xml文件名字一样一样的)
- 业务层对应的mapper映射文件命名可以任意(理论我们要求命名有意义)
- 一般情况下，我们认为业务层写XxxMapper.java, 对应的mapper映射文件XxxMapper.xml，但Mybatis并没有要求文件同名
看懂上面错误认知里的废话后你就会发现，其实也就是在文章后面解决方案二才是正解，方案一就是真正的废话
解决办法在最下面，不想看场景还原的直接跳过，滑倒最下面即可
以下代码中参杂有mybatis-plus，有问题可留言或私信
业务层如下，请先看业务层代码，再看场景
@Service
public class BrandsServiceImpl extends ServiceImpl<BrandsMapper, Settler> implements BrandsService {
@Override
public String brandsInfoForPage(Page<SettlerInfoDTO> page) {
return this.baseMapper.brandsInfoForPage(page.getParams());
}
}
场景一
比如说的下图：
BrandsMapper.java 所需要的映射文件应该是 BrandsMapper.xml, 但是在resources中却没有找到这个文件(BrandsMapper1.xml不是它的映射，因为名字不同或者压根就没有这个文字)
场景二
比如说的下图：
BrandsMapper.java 所需要的映射文件应该是 BrandsMapper.xml, 在resources中也有这个文件，但是依旧会抱上面这个错误，但是细看右边xml区域，mapper的namespace指定的却不是目标BrandsMapper.java
堆栈日志如下:
2022-02-21 11:58:08.336 ERROR 32092 --- [-nio-806-exec-2] c.w.common.config.WeiyaResponseAdvisor : Invalid bound statement (not found): com.xxx.supplier.cms.mapper.BrandsMapper.brandsInfoForPage
org.apache.ibatis.binding.BindingException: Invalid bound statement (not found): com.xxx.supplier.cms.mapper.BrandsMapper.brandsInfoForPage
at org.apache.ibatis.binding.MapperMethod$SqlCommand.<init>(MapperMethod.java:235) ~[mybatis-3.5.6.jar:3.5.6]
at com.baomidou.mybatisplus.core.override.MybatisMapperMethod.<init>(MybatisMapperMethod.java:51) ~[mybatis-plus-core-3.4.2.jar:3.4.2]
at com.baomidou.mybatisplus.core.override.MybatisMapperProxy.lambda$cachedInvoker$0(MybatisMapperProxy.java:111) ~[mybatis-plus-core-3.4.2.jar:3.4.2]
at java.util.concurrent.ConcurrentHashMap.computeIfAbsent(ConcurrentHashMap.java:1660) ~[na:1.8.0_221]
at com.baomidou.mybatisplus.core.toolkit.CollectionUtils.computeIfAbsent(CollectionUtils.java:117) ~[mybatis-plus-core-3.4.2.jar:3.4.2]
at com.baomidou.mybatisplus.core.override.MybatisMapperProxy.cachedInvoker(MybatisMapperProxy.java:98) ~[mybatis-plus-core-3.4.2.jar:3.4.2]
at com.baomidou.mybatisplus.core.override.MybatisMapperProxy.invoke(MybatisMapperProxy.java:89) ~[mybatis-plus-core-3.4.2.jar:3.4.2]
at com.sun.proxy.$Proxy145.brandsInfoForPage(Unknown Source) ~[na:na]
at com.xxx.supplier.cms.service.impl.BrandsServiceImpl.brandsInfoForPage(BrandsServiceImpl.java:43) ~[classes/:na]
at com.xxx.supplier.cms.service.impl.BrandsServiceImpl$$FastClassBySpringCGLIB$$5daf8fa3.invoke(<generated>) ~[classes/:na]
at org.springframework.cglib.proxy.MethodProxy.invoke(MethodProxy.java:218) ~[spring-core-5.2.2.RELEASE.jar:5.2.2.RELEASE]
at org.springframework.aop.framework.CglibAopProxy$DynamicAdvisedInterceptor.intercept(CglibAopProxy.java:685) ~[spring-aop-5.2.2.RELEASE.jar:5.2.2.RELEASE]
at com.xxx.supplier.cms.service.impl.BrandsServiceImpl$$EnhancerBySpringCGLIB$$c26c57f4.brandsInfoForPage(<generated>) ~[classes/:na]
at com.xxx.supplier.cms.controller.BrandsController.brandInfos(BrandsController.java:41) ~[classes/:na]
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method) ~[na:1.8.0_221]
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62) ~[na:1.8.0_221]
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43) ~[na:1.8.0_221]
at java.lang.reflect.Method.invoke(Method.java:498) ~[na:1.8.0_221]
at org.springframework.web.method.support.InvocableHandlerMethod.doInvoke(InvocableHandlerMethod.java:190) ~[spring-web-5.2.2.RELEASE.jar:5.2.2.RELEASE]
at org.springframework.web.method.support.InvocableHandlerMethod.invokeForRequest(InvocableHandlerMethod.java:138) ~[spring-web-5.2.2.RELEASE.jar:5.2.2.RELEASE]
at org.springframework.web.servlet.mvc.method.annotation.ServletInvocableHandlerMethod.invokeAndHandle(ServletInvocableHandlerMethod.java:106) ~[spring-webmvc-5.2.2.RELEASE.jar:5.2.2.RELEASE]
at org.springframework.web.servlet.mvc.method.annotation.RequestMappingHandlerAdapter.invokeHandlerMethod(RequestMappingHandlerAdapter.java:888) ~[spring-webmvc-5.2.2.RELEASE.jar:5.2.2.RELEASE]
at org.springframework.web.servlet.mvc.method.annotation.RequestMappingHandlerAdapter.handleInternal(RequestMappingHandlerAdapter.java:793) ~[spring-webmvc-5.2.2.RELEASE.jar:5.2.2.RELEASE]
at org.springframework.web.servlet.mvc.method.AbstractHandlerMethodAdapter.handle(AbstractHandlerMethodAdapter.java:87) ~[spring-webmvc-5.2.2.RELEASE.jar:5.2.2.RELEASE]
at org.springframework.web.servlet.DispatcherServlet.doDispatch(DispatcherServlet.java:1040) ~[spring-webmvc-5.2.2.RELEASE.jar:5.2.2.RELEASE]
at org.springframework.web.servlet.DispatcherServlet.doService(DispatcherServlet.java:943) ~[spring-webmvc-5.2.2.RELEASE.jar:5.2.2.RELEASE]
at org.springframework.web.servlet.FrameworkServlet.processRequest(FrameworkServlet.java:1006) [spring-webmvc-5.2.2.RELEASE.jar:5.2.2.RELEASE]
at org.springframework.web.servlet.FrameworkServlet.doPost(FrameworkServlet.java:909) [spring-webmvc-5.2.2.RELEASE.jar:5.2.2.RELEASE]
at javax.servlet.http.HttpServlet.service(HttpServlet.java:660) [tomcat-embed-core-9.0.29.jar:9.0.29]
at org.springframework.web.servlet.FrameworkServlet.service(FrameworkServlet.java:883) [spring-webmvc-5.2.2.RELEASE.jar:5.2.2.RELEASE]
at javax.servlet.http.HttpServlet.service(HttpServlet.java:741) [tomcat-embed-core-9.0.29.jar:9.0.29]
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:231) [tomcat-embed-core-9.0.29.jar:9.0.29]
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166) [tomcat-embed-core-9.0.29.jar:9.0.29]
at org.apache.tomcat.websocket.server.WsFilter.doFilter(WsFilter.java:53) [tomcat-embed-websocket-9.0.29.jar:9.0.29]
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:193) [tomcat-embed-core-9.0.29.jar:9.0.29]
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166) [tomcat-embed-core-9.0.29.jar:9.0.29]
at org.springframework.boot.actuate.metrics.web.servlet.WebMvcMetricsFilter.doFilterInternal(WebMvcMetricsFilter.java:108) [spring-boot-actuator-2.2.2.RELEASE.jar:2.2.2.RELEASE]
at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:119) [spring-web-5.2.2.RELEASE.jar:5.2.2.RELEASE]
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:193) [tomcat-embed-core-9.0.29.jar:9.0.29]
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166) [tomcat-embed-core-9.0.29.jar:9.0.29]
at org.springframework.web.filter.CharacterEncodingFilter.doFilterInternal(CharacterEncodingFilter.java:201) [spring-web-5.2.2.RELEASE.jar:5.2.2.RELEASE]
at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:119) [spring-web-5.2.2.RELEASE.jar:5.2.2.RELEASE]
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:193) [tomcat-embed-core-9.0.29.jar:9.0.29]
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166) [tomcat-embed-core-9.0.29.jar:9.0.29]
at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:202) [tomcat-embed-core-9.0.29.jar:9.0.29]
at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:96) [tomcat-embed-core-9.0.29.jar:9.0.29]
at org.apache.catalina.authenticator.AuthenticatorBase.invoke(AuthenticatorBase.java:526) [tomcat-embed-core-9.0.29.jar:9.0.29]
at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:139) [tomcat-embed-core-9.0.29.jar:9.0.29]
at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:92) [tomcat-embed-core-9.0.29.jar:9.0.29]
at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:74) [tomcat-embed-core-9.0.29.jar:9.0.29]
at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:343) [tomcat-embed-core-9.0.29.jar:9.0.29]
at org.apache.coyote.http11.Http11Processor.service(Http11Processor.java:367) [tomcat-embed-core-9.0.29.jar:9.0.29]
at org.apache.coyote.AbstractProcessorLight.process(AbstractProcessorLight.java:65) [tomcat-embed-core-9.0.29.jar:9.0.29]
at org.apache.coyote.AbstractProtocol$ConnectionHandler.process(AbstractProtocol.java:860) [tomcat-embed-core-9.0.29.jar:9.0.29]
at org.apache.tomcat.util.net.NioEndpoint$SocketProcessor.doRun(NioEndpoint.java:1591) [tomcat-embed-core-9.0.29.jar:9.0.29]
at org.apache.tomcat.util.net.SocketProcessorBase.run(SocketProcessorBase.java:49) [tomcat-embed-core-9.0.29.jar:9.0.29]
at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1149) [na:1.8.0_221]
at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:624) [na:1.8.0_221]
at org.apache.tomcat.util.threads.TaskThread$WrappingRunnable.run(TaskThread.java:61) [tomcat-embed-core-9.0.29.jar:9.0.29]
at java.lang.Thread.run(Thread.java:748) [na:1.8.0_221]
解决方向：
按照上面场景来看，
第一：
查看你xxxMapper.java 对应的xxxMapper.xml 是否存在，名字是否一样(建议复制名字后对xml文件进行重命名)
第二：
查看你的xxxMapper.xml 中mapper节点namespace指定的xxxMapper.java是不是你业务的Mapper，可以按照ctrl(command) + 鼠标左键点击看看跳转情况，代码如下：
<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE mapper PUBLIC "-//mybatis.org//DTD Mapper 3.0//EN"
"http://mybatis.org/dtd/mybatis-3-mapper.dtd">
<mapper namespace="com.xxx.mapper.xxxMapper"></mapper>
如果有来生，我要做一棵树，站成永恒，没有悲欢的姿势，一半在尘土里安详，一半在风里飞扬；一半洒落荫凉，一半沐浴阳光，非常沉默、非常骄傲。从不依靠、从不寻找。
如果有来生，我要化成一阵风，一瞬间也能成为永恒。没有善感的情怀，没有多情的眼睛。一半在雨里洒脱，一半在春光里旅行；寂寞了，孤自去远行，把淡淡的思念统带走，从不思念、从不爱恋。 ------三毛