产生这个问题我测试了很多版本，3.0.3、3.2.1以及最新版本，都存在这个问题，只要用lambda表达式.eq()等方法就会报错 报错信息来自源码里面MybatisPlusException: This is impossible to happen 来至SerializedLambda 类导致lambda表达错误。注释掉spring-boot-maven-plugin 包分离代码就好了

解决问题来源 https://github.com/baomidou/mybatis-plus/issues/946

这个问题引起是因为spring-boot-maven-plugin 包分离导致的代码如下：

<!--            <plugin>-->
<!--                <groupId>org.springframework.boot</groupId>-->
<!--                <artifactId>spring-boot-maven-plugin</artifactId>-->
<!--                <configuration>-->

<!--                    &lt;!&ndash;打包时排除包依赖&ndash;&gt;-->
<!--                    <includes> -->
<!--                        <include>-->
<!--                            <groupId>nothing</groupId>-->
<!--                            <artifactId>nothing</artifactId>-->
<!--                        </include>-->
<!--                    </includes>-->
<!--                </configuration>-->
<!--            </plugin>-->

因为包分离有问题，所以这个问题代码我已经注释，这个会导致如下报错： org.mybatis.spring.MyBatisSystemException: nested exception is org.apache.ibatis.builder.BuilderException: Error evaluating expression 'ew != null and !ew.emptyOfWhere'. Cause: org.apache.ibatis.ognl.OgnlException: emptyOfWhere [com.baomidou.mybatisplus.core.exceptions.MybatisPlusException: This is impossible to happen] at org.mybatis.spring.MyBatisExceptionTranslator.translateExceptionIfPossible(MyBatisExceptionTranslator.java:77) at org.mybatis.spring.SqlSessionTemplate$SqlSessionInterceptor.invoke(SqlSessionTemplate.java:446) at com.sun.proxy.$Proxy103.selectOne(Unknown Source) at org.mybatis.spring.SqlSessionTemplate.selectOne(SqlSessionTemplate.java:166) at com.baomidou.mybatisplus.core.override.PageMapperMethod.execute(PageMapperMethod.java:101) at com.baomidou.mybatisplus.core.override.PageMapperProxy.invoke(PageMapperProxy.java:64) at com.sun.proxy.$Proxy168.selectCount(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:343) at org.springframework.aop.framework.ReflectiveMethodInvocation.invokeJoinpoint(ReflectiveMethodInvoca

n.com.bjfanuc.mapper.TMsgUserMapper.selectTMsgUserByUserId

DEBUG - 2020-12-14 21:01:36,667 - cn.com.bjfanuc.mapper.TMsgUserMapper.selectTMsgUserByUserId - <== Total: 1 DEBUG - 2020-12-14 21:01:36,667 - cn.com.bjfanuc.mapper.UrlMapper.getUrlByRole - <== Total: 1 INFO - 2020-12-14 21:01:39,307 - cn.com.bjfanuc.config.datasource.DataSourceContextHolder - 切换数据源 => serviceDb INFO - 2020-12-14 21:01:39,314 - cn.com.bjfanuc.config.datasource.DataSourceContextHolder - 切换数据源 => serviceDb INFO - 2020-12-14 21:01:39,317 - cn.com.bjfanuc.config.datasource.DataSourceContextHolder - 切换数据源 => serviceDb ERROR - 2020-12-14 21:01:39,317 - cn.com.bjfanuc.controller.SysMessageController - >>>>>>>>>>> URL: /sysmsg/getUnReadMsgCount, throw Exception => {} org.mybatis.spring.MyBatisSystemException: nested exception is org.apache.ibatis.builder.BuilderException: Error evaluating expression 'ew != null and !ew.emptyOfWhere'. Cause: org.apache.ibatis.ognl.OgnlException: emptyOfWhere [com.baomidou.mybatisplus.core.exceptions.MybatisPlusException: This is impossible to happen] at org.mybatis.spring.MyBatisExceptionTranslator.translateExceptionIfPossible(MyBatisExceptionTranslator.java:77) at org.mybatis.spring.SqlSessionTemplate$SqlSessionInterceptor.invoke(SqlSessionTemplate.java:446) at com.sun.proxy.$Proxy101.selectOne(Unknown Source) at org.mybatis.spring.SqlSessionTemplate.selectOne(SqlSessionTemplate.java:166) at com.baomidou.mybatisplus.core.override.PageMapperMethod.execute(PageMapperMethod.java:101) at com.baomidou.mybatisplus.core.override.PageMapperProxy.invoke(PageMapperProxy.java:64) at com.sun.proxy.$Proxy128.selectCount(Unknown Source) at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method) at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62) at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43) at java.lang.reflect.Method.invoke(Method.java:498) at org.springframework.aop.support.AopUtils.invokeJoinpointUsingReflection(AopUtils.java:343) at org.springframework.aop.framework.ReflectiveMethodInvocation.invokeJoinpoint(ReflectiveMethodInvocation.java:198) at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:163) at org.springframework.dao.support.PersistenceExceptionTranslationInterceptor.invoke(PersistenceExceptionTranslationInterceptor.java:139) at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:186) at org.springframework.aop.framework.JdkDynamicAopProxy.invoke(JdkDynamicAopProxy.java:212) at com.sun.proxy.$Proxy129.selectCount(Unknown Source) at cn.com.bjfanuc.service.impl.TMsgUserServiceImpl.getUnReadMsgCount(TMsgUserServiceImpl.java:110) at cn.com.bjfanuc.service.impl.TMsgUserServiceImpl$$FastClassBySpringCGLIB$$69ef87cd.invoke() at org.springframework.cglib.proxy.MethodProxy.invoke(MethodProxy.java:218) at org.springframework.aop.framework.CglibAopProxy$CglibMethodInvocation.invokeJoinpoint(CglibAopProxy.java:749) at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:163) at org.springframework.aop.framework.adapter.MethodBeforeAdviceInterceptor.invoke(MethodBeforeAdviceInterceptor.java:56) at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:186) at org.springframework.aop.aspectj.AspectJAfterAdvice.invoke(AspectJAfterAdvice.java:47) at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:186) at org.springframework.aop.interceptor.ExposeInvocationInterceptor.invoke(ExposeInvocationInterceptor.java:93) at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:186) at org.springframework.aop.framework.CglibAopProxy$DynamicAdvisedInterceptor.intercept(CglibAopProxy.java:688) at cn.com.bjfanuc.service.impl.TMsgUserServiceImpl$$EnhancerBySpringCGLIB$$bfabf780.getUnReadMsgCount() at cn.com.bjfanuc.controller.SysMessageController.getUnReadMsgCount(SysMessageController.java:274) 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:189) at org.springframework.web.method.support.InvocableHandlerMethod.invokeForRequest(InvocableHandlerMethod.java:138) at org.springframework.web.servlet.mvc.method.annotation.ServletInvocableHandlerMethod.invokeAndHandle(ServletInvocableHandlerMethod.java:102) at org.springframework.web.servlet.mvc.method.annotation.RequestMappingHandlerAdapter.invokeHandlerMethod(RequestMappingHandlerAdapter.java:895) at org.springframework.web.servlet.mvc.method.annotation.RequestMappingHandlerAdapter.handleInternal(RequestMappingHandlerAdapter.java:800) at org.springframework.web.servlet.mvc.method.AbstractHandlerMethodAdapter.handle(AbstractHandlerMethodAdapter.java:87) at org.springframework.web.servlet.DispatcherServlet.doDispatch(DispatcherServlet.java:1038) at org.springframework.web.servlet.DispatcherServlet.doService(DispatcherServlet.java:942) at org.springframework.web.servlet.FrameworkServlet.processRequest(FrameworkServlet.java:1005) at org.springframework.web.servlet.FrameworkServlet.doPost(FrameworkServlet.java:908) at javax.servlet.http.HttpServlet.service(HttpServlet.java:660) at org.springframework.web.servlet.FrameworkServlet.service(FrameworkServlet.java:882) 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 cn.com.bjfanuc.filter.MyFilterHandler.doFilter(MyFilterHandler.java:40) 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:200) at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:107) 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:199) at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:96) at org.apache.catalina.authenticator.AuthenticatorBase.invoke(AuthenticatorBase.java:490) 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:408) at org.apache.coyote.AbstractProcessorLight.process(AbstractProcessorLight.java:66) at org.apache.coyote.AbstractProtocol$ConnectionHandler.process(AbstractProtocol.java:791) at org.apache.tomcat.util.net.NioEndpoint$SocketProcessor.doRun(NioEndpoint.java:1417) 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) Caused by: org.apache.ibatis.builder.BuilderException: Error evaluating expression 'ew != null and !ew.emptyOfWhere'. Cause: org.apache.ibatis.ognl.OgnlException: emptyOfWhere [com.baomidou.mybatisplus.core.exceptions.MybatisPlusException: This is impossible to happen] at org.apache.ibatis.scripting.xmltags.OgnlCache.getValue(OgnlCache.java:46) at org.apache.ibatis.scripting.xmltags.ExpressionEvaluator.evaluateBoolean(ExpressionEvaluator.java:32) at org.apache.ibatis.scripting.xmltags.IfSqlNode.apply(IfSqlNode.java:34) at org.apache.ibatis.scripting.xmltags.MixedSqlNode.apply(MixedSqlNode.java:33) at org.apache.ibatis.scripting.xmltags.DynamicSqlSource.getBoundSql(DynamicSqlSource.java:41) at org.apache.ibatis.mapping.MappedStatement.getBoundSql(MappedStatement.java:292) at org.apache.ibatis.executor.BaseExecutor.query(BaseExecutor.java:134) at org.apache.ibatis.session.defaults.DefaultSqlSession.selectList(DefaultSqlSession.java:148) at org.apache.ibatis.session.defaults.DefaultSqlSession.selectList(DefaultSqlSession.java:141) at org.apache.ibatis.session.defaults.DefaultSqlSession.selectOne(DefaultSqlSession.java:77) 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.mybatis.spring.SqlSessionTemplate$SqlSessionInterceptor.invoke(SqlSessionTemplate.java:433) ... 75 common frames omitted Caused by: org.apache.ibatis.ognl.OgnlException: emptyOfWhere at org.apache.ibatis.ognl.OgnlRuntime.getMethodValue(OgnlRuntime.java:1711) at org.apache.ibatis.ognl.ObjectPropertyAccessor.getPossibleProperty(ObjectPropertyAccessor.java:60) at org.apache.ibatis.ognl.ObjectPropertyAccessor.getProperty(ObjectPropertyAccessor.java:147) at org.apache.ibatis.ognl.OgnlRuntime.getProperty(OgnlRuntime.java:2685) at org.apache.ibatis.ognl.ASTProperty.getValueBody(ASTProperty.java:114) at org.apache.ibatis.ognl.SimpleNode.evaluateGetValueBody(SimpleNode.java:212) at org.apache.ibatis.ognl.SimpleNode.getValue(SimpleNode.java:258) at org.apache.ibatis.ognl.ASTChain.getValueBody(ASTChain.java:141) at org.apache.ibatis.ognl.SimpleNode.evaluateGetValueBody(SimpleNode.java:212) at org.apache.ibatis.ognl.SimpleNode.getValue(SimpleNode.java:258) at org.apache.ibatis.ognl.ASTNot.getValueBody(ASTNot.java:49) at org.apache.ibatis.ognl.SimpleNode.evaluateGetValueBody(SimpleNode.java:212) at org.apache.ibatis.ognl.SimpleNode.getValue(SimpleNode.java:258) at org.apache.ibatis.ognl.ASTAnd.getValueBody(ASTAnd.java:61) at org.apache.ibatis.ognl.SimpleNode.evaluateGetValueBody(SimpleNode.java:212) at org.apache.ibatis.ognl.SimpleNode.getValue(SimpleNode.java:258) at org.apache.ibatis.ognl.Ognl.getValue(Ognl.java:470) at org.apache.ibatis.ognl.Ognl.getValue(Ognl.java:434) at org.apache.ibatis.scripting.xmltags.OgnlCache.getValue(OgnlCache.java:44) ... 89 common frames omitted Caused by: com.baomidou.mybatisplus.core.exceptions.MybatisPlusException: This is impossible to happen at com.baomidou.mybatisplus.core.toolkit.ExceptionUtils.mpe(ExceptionUtils.java:41) at com.baomidou.mybatisplus.core.toolkit.support.SerializedLambda.convert(SerializedLambda.java:67) at com.baomidou.mybatisplus.core.toolkit.LambdaUtils.lambda$resolve$23(LambdaUtils.java:57) at java.util.Optional.orElseGet(Optional.java:267) at com.baomidou.mybatisplus.core.toolkit.LambdaUtils.resolve(LambdaUtils.java:56) at com.baomidou.mybatisplus.core.conditions.AbstractLambdaWrapper.columnToString(AbstractLambdaWrapper.java:47) at com.baomidou.mybatisplus.core.conditions.AbstractLambdaWrapper.columnToString(AbstractLambdaWrapper.java:38) at com.baomidou.mybatisplus.core.conditions.AbstractWrapper.lambda$in$8387bc68$1(AbstractWrapper.java:252) at java.util.stream.ReferencePipeline$3$1.accept(ReferencePipeline.java:193) at java.util.ArrayList$ArrayListSpliterator.forEachRemaining(ArrayList.java:1384) at java.util.stream.AbstractPipeline.copyInto(AbstractPipeline.java:482) at java.util.stream.AbstractPipeline.wrapAndCopyInto(AbstractPipeline.java:472) at java.util.stream.ReduceOps$ReduceOp.evaluateSequential(ReduceOps.java:708) at java.util.stream.AbstractPipeline.evaluate(AbstractPipeline.java:234) at java.util.stream.ReferencePipeline.collect(ReferencePipeline.java:566) at com.baomidou.mybatisplus.core.conditions.segments.NormalSegmentList.getSqlSegment(NormalSegmentList.java:92) at com.baomidou.mybatisplus.core.conditions.segments.MergeSegments.getSqlSegment(MergeSegments.java:66) at com.baomidou.mybatisplus.core.conditions.AbstractWrapper.getSqlSegment(AbstractWrapper.java:436) at com.baomidou.mybatisplus.core.conditions.Wrapper.isEmptyOfWhere(Wrapper.java:58) at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method) at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62) at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43) at java.lang.reflect.Method.invoke(Method.java:498) at org.apache.ibatis.ognl.OgnlRuntime.invokeMethod(OgnlRuntime.java:899) at org.apache.ibatis.ognl.OgnlRuntime.getMethodValue(OgnlRuntime.java:1709) ... 107 common frames omitted Caused by: java.lang.ClassNotFoundException: cn.com.bjfanuc.service.impl.TMsgUserServiceImpl at java.net.URLClassLoader.findClass(URLClassLoader.java:382) at java.lang.ClassLoader.loadClass(ClassLoader.java:418) at sun.misc.Launcher$AppClassLoader.loadClass(Launcher.java:352) at java.lang.ClassLoader.loadClass(ClassLoader.java:351) at java.lang.Class.forName0(Native Method) at java.lang.Class.forName(Class.java:348) at java.io.ObjectInputStream.resolveClass(ObjectInputStream.java:757) at com.baomidou.mybatisplus.core.toolkit.support.SerializedLambda$1.resolveClass(SerializedLambda.java:61) at java.io.ObjectInputStream.readNonProxyDesc(ObjectInputStream.java:1985) at java.io.ObjectInputStream.readClassDesc(ObjectInputStream.java:1849) at java.io.ObjectInputStream.readClass(ObjectInputStream.java:1812) at java.io.ObjectInputStream.readObject0(ObjectInputStream.java:1637) at java.io.ObjectInputStream.defaultReadFields(ObjectInputStream.java:2404) at java.io.ObjectInputStream.readSerialData(ObjectInputStream.java:2328) at java.io.ObjectInputStream.readOrdinaryObject(ObjectInputStream.java:2186) at java.io.ObjectInputStream.readObject0(ObjectInputStream.java:1666) at java.io.ObjectInputStream.readObject(ObjectInputStream.java:502) at java.io.ObjectInputStream.readObject(ObjectInputStream.java:460) at com.baomidou.mybatisplus.core.toolkit.support.SerializedLambda.convert(SerializedLambda.java:65)

Comment From: arvin-xiao

最近也是出现问题 mybatis-plus 3.1.0使用lambda查询数据出现下面异常 nested exception is org.apache.ibatis.builder.BuilderException: Error evaluating expression 'ew.sqlSegment != null and ew.sqlSegment != '' and ew.nonEmptyOfWhere'. Cause: org.apache.ibatis.ognl.OgnlException: sqlSegment [java.lang.OutOfMemoryError: Java heap space]

Comment From: nieqiurong

下载这个解压到本地仓库使用一下. 链接：https://share.weiyun.com/8DQxuQ8x 密码：kwenfu