项目使用的是SpringBoot + Mybatis Plus，maven多模块项目，其中有多个模块的resource下面有Mapper.xml文件。这点是问题的前提。。。。。
在配置文件里面也指定了mybatis-plus的xml位置：
mybatis-plus:
# mapper xml映射路径
mapper-locations: classpath*:mapper/**/*Mapper.xml
之前是走的单独的库，也就是走的Mybatis Plus默认的 SqlSessionFactory ，项目是正常的。
但是把项目改为多数据源后，由于在配置文件里面手动创建了 SqlSessionFactory 的 Bean 后，导致调用mybatis-plus自带的方法的时候，是好使的，调用自己手动写的xml方法的时候，就提示参数绑定问题：org.apache.ibatis.binding.BindingException
完整报错信息如下：
org.apache.ibatis.binding.BindingException: Invalid bound statement (not found): gc.cnnvd.framework.ip.mapper.IpAddressMapper.selectByIp
at org.apache.ibatis.binding.MapperMethod$SqlCommand.<init>(MapperMethod.java:235)
at com.baomidou.mybatisplus.core.override.MybatisMapperMethod.<init>(MybatisMapperMethod.java:50)
at com.baomidou.mybatisplus.core.override.MybatisMapperProxy.lambda$cachedMapperMethod$0(MybatisMapperProxy.java:101)
at java.util.concurrent.ConcurrentHashMap.computeIfAbsent(ConcurrentHashMap.java:1660)
at com.baomidou.mybatisplus.core.override.MybatisMapperProxy.cachedMapperMethod(MybatisMapperProxy.java:100)
at com.baomidou.mybatisplus.core.override.MybatisMapperProxy.invoke(MybatisMapperProxy.java:95)
at com.sun.proxy.$Proxy340.selectByIp(Unknown Source)
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.aop.support.AopUtils.invokeJoinpointUsingReflection(AopUtils.java:344)
at org.springframework.aop.framework.ReflectiveMethodInvocation.invokeJoinpoint(ReflectiveMethodInvocation.java:198)
at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:163)
at org.springframework.aop.framework.adapter.MethodBeforeAdviceInterceptor.invoke(MethodBeforeAdviceInterceptor.java:56)
at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:175)
at org.springframework.aop.interceptor.ExposeInvocationInterceptor.invoke(ExposeInvocationInterceptor.java:95)
at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:186)
at org.springframework.aop.framework.JdkDynamicAopProxy.invoke(JdkDynamicAopProxy.java:212)
at com.sun.proxy.$Proxy341.selectByIp(Unknown Source)
at gc.cnnvd.framework.ip.service.impl.IpAddressServiceImpl.getByIp(IpAddressServiceImpl.java:57)
at gc.cnnvd.framework.ip.service.impl.IpAddressServiceImpl$$FastClassBySpringCGLIB$$1.invoke(<generated>)
at org.springframework.cglib.proxy.MethodProxy.invoke(MethodProxy.java:218)
at org.springframework.aop.framework.CglibAopProxy$CglibMethodInvocation.invokeJoinpoint(CglibAopProxy.java:769)
at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:163)
at org.springframework.aop.framework.CglibAopProxy$CglibMethodInvocation.proceed(CglibAopProxy.java:747)
at org.springframework.aop.framework.adapter.MethodBeforeAdviceInterceptor.invoke(MethodBeforeAdviceInterceptor.java:56)
at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:175)
at org.springframework.aop.framework.CglibAopProxy$CglibMethodInvocation.proceed(CglibAopProxy.java:747)
at org.springframework.aop.interceptor.ExposeInvocationInterceptor.invoke(ExposeInvocationInterceptor.java:95)
at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:186)
at org.springframework.aop.framework.CglibAopProxy$CglibMethodInvocation.proceed(CglibAopProxy.java:747)
at org.springframework.aop.framework.CglibAopProxy$DynamicAdvisedInterceptor.intercept(CglibAopProxy.java:689)
at gc.cnnvd.framework.ip.service.impl.IpAddressServiceImpl$$EnhancerBySpringCGLIB$$1.getByIp(<generated>)
at gc.cnnvd.framework.log.aop.BaseLogAop.saveSysLoginLog(BaseLogAop.java:971)
at gc.cnnvd.aop.LogAop.finish(LogAop.java:87)
at gc.cnnvd.framework.log.aop.BaseLogAop.handleAfterReturn(BaseLogAop.java:345)
at gc.cnnvd.framework.log.aop.BaseLogAop.handle(BaseLogAop.java:328)
at gc.cnnvd.aop.LogAop.doAround(LogAop.java:56)
at gc.cnnvd.aop.LogAop$$FastClassBySpringCGLIB$$1.invoke(<generated>)
at org.springframework.cglib.proxy.MethodProxy.invoke(MethodProxy.java:218)
at org.springframework.aop.framework.CglibAopProxy$DynamicAdvisedInterceptor.intercept(CglibAopProxy.java:685)
at gc.cnnvd.aop.LogAop$$EnhancerBySpringCGLIB$$1.doAround(<generated>)
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.aop.aspectj.AbstractAspectJAdvice.invokeAdviceMethodWithGivenArgs(AbstractAspectJAdvice.java:644)
at org.springframework.aop.aspectj.AbstractAspectJAdvice.invokeAdviceMethod(AbstractAspectJAdvice.java:633)
at org.springframework.aop.aspectj.AspectJAroundAdvice.invoke(AspectJAroundAdvice.java:70)
at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:186)
at org.springframework.aop.framework.CglibAopProxy$CglibMethodInvocation.proceed(CglibAopProxy.java:747)
at org.springframework.aop.aspectj.AspectJAfterThrowingAdvice.invoke(AspectJAfterThrowingAdvice.java:62)
at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:186)
at org.springframework.aop.framework.CglibAopProxy$CglibMethodInvocation.proceed(CglibAopProxy.java:747)
at org.springframework.aop.interceptor.ExposeInvocationInterceptor.invoke(ExposeInvocationInterceptor.java:95)
at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:186)
at org.springframework.aop.framework.CglibAopProxy$CglibMethodInvocation.proceed(CglibAopProxy.java:747)
at org.springframework.aop.framework.CglibAopProxy$DynamicAdvisedInterceptor.intercept(CglibAopProxy.java:689)
at gc.cnnvd.system.login.controller.LoginController$$EnhancerBySpringCGLIB$$1.login(<generated>)
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.method.support.InvocableHandlerMethod.doInvoke(InvocableHandlerMethod.java:190)
at org.springframework.web.method.support.InvocableHandlerMethod.invokeForRequest(InvocableHandlerMethod.java:138)
at org.springframework.web.servlet.mvc.method.annotation.ServletInvocableHandlerMethod.invokeAndHandle(ServletInvocableHandlerMethod.java:106)
at org.springframework.web.servlet.mvc.method.annotation.RequestMappingHandlerAdapter.invokeHandlerMethod(RequestMappingHandlerAdapter.java:879)
at org.springframework.web.servlet.mvc.method.annotation.RequestMappingHandlerAdapter.handleInternal(RequestMappingHandlerAdapter.java:793)
at org.springframework.web.servlet.mvc.method.AbstractHandlerMethodAdapter.handle(AbstractHandlerMethodAdapter.java:87)
at org.springframework.web.servlet.DispatcherServlet.doDispatch(DispatcherServlet.java:1040)
at org.springframework.web.servlet.DispatcherServlet.doService(DispatcherServlet.java:943)
at org.springframework.web.servlet.FrameworkServlet.processRequest(FrameworkServlet.java:1006)
at org.springframework.web.servlet.FrameworkServlet.doPost(FrameworkServlet.java:909)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:660)
at org.springframework.web.servlet.FrameworkServlet.service(FrameworkServlet.java:883)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:741)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:231)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166)
at org.apache.tomcat.websocket.server.WsFilter.doFilter(WsFilter.java:53)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:193)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166)
at com.github.xiaoymin.knife4j.spring.filter.ProductionSecurityFilter.doFilter(ProductionSecurityFilter.java:53)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:193)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166)
at com.github.xiaoymin.knife4j.spring.filter.SecurityBasicAuthFilter.doFilter(SecurityBasicAuthFilter.java:87)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:193)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166)
at org.apache.shiro.web.servlet.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:112)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:193)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166)
at org.apache.shiro.web.servlet.ProxiedFilterChain.doFilter(ProxiedFilterChain.java:61)
at org.apache.shiro.web.servlet.AdviceFilter.executeChain(AdviceFilter.java:108)
at org.apache.shiro.web.servlet.AdviceFilter.doFilterInternal(AdviceFilter.java:137)
at org.apache.shiro.web.servlet.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:125)
at org.apache.shiro.web.servlet.ProxiedFilterChain.doFilter(ProxiedFilterChain.java:66)
at org.apache.shiro.web.servlet.AbstractShiroFilter.executeChain(AbstractShiroFilter.java:449)
at org.apache.shiro.web.servlet.AbstractShiroFilter$1.call(AbstractShiroFilter.java:365)
at org.apache.shiro.subject.support.SubjectCallable.doCall(SubjectCallable.java:90)
at org.apache.shiro.subject.support.SubjectCallable.call(SubjectCallable.java:83)
at org.apache.shiro.subject.support.DelegatingSubject.execute(DelegatingSubject.java:387)
at org.apache.shiro.web.servlet.AbstractShiroFilter.doFilterInternal(AbstractShiroFilter.java:362)
at org.apache.shiro.web.servlet.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:125)
at org.springframework.web.filter.DelegatingFilterProxy.invokeDelegate(DelegatingFilterProxy.java:358)
at org.springframework.web.filter.DelegatingFilterProxy.doFilter(DelegatingFilterProxy.java:271)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:193)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166)
at gc.cnnvd.framework.core.filter.ParamsFilter.doFilter(ParamsFilter.java:18)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:193)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166)
at gc.cnnvd.framework.core.xss.XssFilter.doFilter(XssFilter.java:43)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:193)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166)
at gc.cnnvd.framework.core.filter.RequestDetailFilter.doFilter(RequestDetailFilter.java:55)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:193)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166)
at org.springframework.web.filter.RequestContextFilter.doFilterInternal(RequestContextFilter.java:100)
at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:119)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:193)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166)
at org.springframework.web.filter.FormContentFilter.doFilterInternal(FormContentFilter.java:93)
at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:119)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:193)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166)
at org.springframework.boot.actuate.metrics.web.servlet.WebMvcMetricsFilter.doFilterInternal(WebMvcMetricsFilter.java:109)
at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:119)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:193)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166)
at org.springframework.web.filter.CharacterEncodingFilter.doFilterInternal(CharacterEncodingFilter.java:201)
at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:119)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:193)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166)
at org.springframework.web.filter.CorsFilter.doFilterInternal(CorsFilter.java:92)
at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:119)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:193)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166)
at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:202)
at org.apache.catalina.core.StandardContextValve.__invoke(StandardContextValve.java:96)
at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:41002)
at org.apache.catalina.authenticator.AuthenticatorBase.invoke(AuthenticatorBase.java:541)
at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:139)
at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:92)
at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:74)
at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:343)
at org.apache.coyote.http11.Http11Processor.service(Http11Processor.java:367)
at org.apache.coyote.AbstractProcessorLight.process(AbstractProcessorLight.java:65)
at org.apache.coyote.AbstractProtocol$ConnectionHandler.process(AbstractProtocol.java:868)
at org.apache.tomcat.util.net.NioEndpoint$SocketProcessor.doRun(NioEndpoint.java:1639)
at org.apache.tomcat.util.net.SocketProcessorBase.run(SocketProcessorBase.java:49)
at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1149)
at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:624)
at org.apache.tomcat.util.threads.TaskThread$WrappingRunnable.run(TaskThread.java:61)
at java.lang.Thread.run(Thread.java:748)
由于改动只是新增了配置多数据源的配置文件，其中有个配置文件中定义了一个名为 SqlSessionFactory 的 Bean：
/**
* 使用MyBatis Plus的sqlSessionFactory代替，
* 此处注意mybatis与mybatisPlus的配置不同，不然扫描不到对数据操作的方法。会报未绑定错误
* @return sqlSessionFactory
* @throws Exception
*/
@Bean
public SqlSessionFactory sqlSessionFactory() throws Exception {
MybatisSqlSessionFactoryBean sqlSessionFactoryBean = new MybatisSqlSessionFactoryBean();
sqlSessionFactoryBean.setDataSource(myRoutingDataSource);
// sqlSessionFactoryBean.setMapperLocations(new PathMatchingResourcePatternResolver().getResources("classpath:mapper/**/*.xml"));
org.springframework.core.io.Resource[] resources = new PathMatchingResourcePatternResolver().getResources("classpath:mapper/**/*.xml");
sqlSessionFactoryBean.setMapperLocations(resources);
MybatisConfiguration mybatisConfiguration = new MybatisConfiguration();
sqlSessionFactoryBean.setConfiguration(mybatisConfiguration);
return sqlSessionFactoryBean.getObject();
}
可以看到代码里面指定了扫描的位置为：classpath:mapper/**/*.xml，乍一看，也没毛病。其实就是mybatis用的多了，而mybatis-plus这样配置就可能不太行。
把这个报错信息在网上一搜，大多都是说要么是Mapper.xml文件里面映射的Mapper接口的路径有问题，要么是没有在配置文件里面指定mapper文件的扫描位置，对比之后，发现我的问题并不是因为这个，但是因为什么，就不知道了。
折腾了半天之后，无果。。。。。。。。。
其中发现一个比较神奇的问题是，由于项目有多个maven子模块里面包含mapper.xml文件，其中有一个模块下面的xml文件是可以扫描到的，可以正常查询，另外两个子模块的都报上面的参数绑定异常。
就很诡异，想着是不是maven项目配置问题，导致的，然后仔细对比能扫描到的那个子模块的pom文件，发现里面定义了打包相关的代码。
<build>
<resources>
<resource>
<directory>src/main/resources</directory>
<filtering>true</filtering>
</resource>
</resources>
</build>
上面代码为maven项目打包时，是否想resource下面的文件打包到项目包里面，无论是打包成jar还是打包成war。
其中 filtering 的属性，表示打包时是否动态替换配置文件里面的内容。如果没有动态配置的内容，这里设置true和false都不影响。但是必须得有，否则上面即使配置了扫描路径为 classpath*:mapper/**/*.xml 也是扫描不到xml文件的。
然后就把另外两个有问题的字母块的pom文件里面加上这个。发现还是不行。
然后想着会不会是扫描到了，但是扫描了多次，后面的扫描结果把前面的扫描结果给覆盖了呢？
于是在上面的代码
sqlSessionFactoryBean.setMapperLocations(resources);
打了个断点，看了下 resources，启动的时候，发现只走了一次扫描的过程，扫描结果为正常的子模块下面的xml文件。。。。。。。
然后试着注释掉这个子模块，发现可以扫描到另一个之前扫描不到的子模块下的xml文件了。。。。。。
然后就开始搜maven多模块，扫描多个mapper文件位置，发现有classpath*:mapper/**/*.xml 这种写法，然后试了下，果然能识别到两个子模块下的mapper文件了，接着把另一个子模块的pom文件里面也指定build，接着就完全好使了。。。。。。。
就这一个星号的问题，导致折腾了大半天了。。。。。。
另外，看到一篇博客里面提到关于扫描mapper配置文件位置，mybatis-plus 3.1.2 版本后，里面已经设置默认扫描位置为：classpath*:mapper/**/*.xml，见配置文件：MybatisPlusProperties
而mybatis源码MybatisProperties里面貌似没有，所以还是需要手动声明扫描位置：
mybatis:
mapper-locations: mapper/*.xml