日志

上了服务器一看，Mybatis报错，接口还是个相当频繁的接口，一想，完了，绩效大概率不保。

2023-08-08 09:52:05,386|aaaaaaaaa|XXXXXXXXXXXXXX|unknown exception occurred
org.mybatis.spring.MyBatisSystemException: nested exception is org.apache.ibatis.builder.BuilderException: Error evaluating expression 'projects != null and projects.size() > 0 '. Cause: org.apache.ibatis.ognl.MethodFailedException: Method "size" failed for object [aaa,bbb,ccc] [java.lang.IllegalAccessException: Class org.apache.ibatis.ognl.OgnlRuntime can not access a member of class java.util.Arrays$ArrayList with modifiers "public"]
        at org.mybatis.spring.MyBatisExceptionTranslator.translateExceptionIfPossible(MyBatisExceptionTranslator.java:75) ~[mybatis-spring-1.2.2.jar:1.2.2]
        at org.mybatis.spring.SqlSessionTemplate$SqlSessionInterceptor.invoke(SqlSessionTemplate.java:371) ~[mybatis-spring-1.2.2.jar:1.2.2]
        at com.sun.proxy.$Proxy57.selectList(Unknown Source) ~[na:na]
        at org.mybatis.spring.SqlSessionTemplate.selectList(SqlSessionTemplate.java:198) ~[mybatis-spring-1.2.2.jar:1.2.2]
        at org.apache.ibatis.binding.MapperMethod.executeForMany(MapperMethod.java:119) ~[mybatis-3.2.8.jar:3.2.8]
        at org.apache.ibatis.binding.MapperMethod.execute(MapperMethod.java:63) ~[mybatis-3.2.8.jar:3.2.8]
        at org.apache.ibatis.binding.MapperProxy.invoke(MapperProxy.java:52) ~[mybatis-3.2.8.jar:3.2.8]
        at com.sun.proxy.$Proxy102.queryExperienceCardOrder(Unknown Source) ~[na:na]
      // 业务相关堆栈，保险起见不贴了
        at org.springframework.cglib.proxy.MethodProxy.invoke(MethodProxy.java:204) ~[spring-core-4.3.6.RELEASE.jar:4.3.6.RELEASE]
        at org.springframework.aop.framework.CglibAopProxy$DynamicAdvisedInterceptor.intercept(CglibAopProxy.java:652) ~[spring-aop-4.3.6.RELEASE.jar:4.3.6.RELEASE]
        at com.xxxxxxxxxxxxxxxxxxxxxx$$EnhancerBySpringCGLIB$$b85a94bd.queryHasExperienceCardNew(<generated>) ~[zuhao-user-service-1.0.0.jar:na]
        at sun.reflect.GeneratedMethodAccessor564.invoke(Unknown Source) ~[na:na]
        at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43) ~[na:1.8.0_131]
        at java.lang.reflect.Method.invoke(Method.java:498) ~[na:1.8.0_131]
        at org.springframework.aop.support.AopUtils.invokeJoinpointUsingReflection(AopUtils.java:333) ~[spring-aop-4.3.6.RELEASE.jar:4.3.6.RELEASE]
        at org.springframework.aop.framework.ReflectiveMethodInvocation.invokeJoinpoint(ReflectiveMethodInvocation.java:190) [spring-aop-4.3.6.RELEASE.jar:4.3.6.RELEASE]
        at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:157) [spring-aop-4.3.6.RELEASE.jar:4.3.6.RELEASE]
        at xxxxxxxxxxxxx.common.interceptor.ApiInterceptor.invoke(ApiInterceptor.java:79) ~[common-0.0.9-20211228.052440-12.jar:na]
        at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:179) [spring-aop-4.3.6.RELEASE.jar:4.3.6.RELEASE]
        at org.springframework.aop.framework.JdkDynamicAopProxy.invoke(JdkDynamicAopProxy.java:213) [spring-aop-4.3.6.RELEASE.jar:4.3.6.RELEASE]
        at com.sun.proxy.$Proxy185.queryHasExperienceCardNew(Unknown Source) [na:na]
        at com.alibaba.dubbo.common.bytecode.Wrapper36.invokeMethod(Wrapper36.java) [na:2.5.3]
        at com.alibaba.dubbo.rpc.proxy.javassist.JavassistProxyFactory$1.doInvoke(JavassistProxyFactory.java:46) [dubbo-2.5.3.jar:2.5.3]
        at com.alibaba.dubbo.rpc.proxy.AbstractProxyInvoker.invoke(AbstractProxyInvoker.java:72) [dubbo-2.5.3.jar:2.5.3]
        at com.alibaba.dubbo.rpc.protocol.InvokerWrapper.invoke(InvokerWrapper.java:53) [dubbo-2.5.3.jar:2.5.3]
        at com.alibaba.dubbo.rpc.filter.ExceptionFilter.invoke(ExceptionFilter.java:64) [dubbo-2.5.3.jar:2.5.3]
        at com.alibaba.dubbo.rpc.protocol.ProtocolFilterWrapper$1.invoke(ProtocolFilterWrapper.java:91) [dubbo-2.5.3.jar:2.5.3]
        at com.alibaba.dubbo.monitor.support.MonitorFilter.invoke$original$LFhJaVNd(MonitorFilter.java:65) [dubbo-2.5.3.jar:2.5.3]
        at com.alibaba.dubbo.monitor.support.MonitorFilter.invoke$original$LFhJaVNd$accessor$urPnHrIw(MonitorFilter.java) [dubbo-2.5.3.jar:2.5.3]
        at com.alibaba.dubbo.monitor.support.MonitorFilter$auxiliary$RJHyKBeq.call(Unknown Source) [dubbo-2.5.3.jar:2.5.3]
        at org.apache.skywalking.apm.agent.core.plugin.interceptor.enhance.InstMethodsInter.intercept(InstMethodsInter.java:86) [skywalking-agent.jar:8.16.0]
        at com.alibaba.dubbo.monitor.support.MonitorFilter.invoke(MonitorFilter.java) [dubbo-2.5.3.jar:2.5.3]
        at com.alibaba.dubbo.rpc.protocol.ProtocolFilterWrapper$1.invoke(ProtocolFilterWrapper.java:91) [dubbo-2.5.3.jar:2.5.3]
        at com.alibaba.dubbo.rpc.filter.TimeoutFilter.invoke(TimeoutFilter.java:42) [dubbo-2.5.3.jar:2.5.3]
        at com.alibaba.dubbo.rpc.protocol.ProtocolFilterWrapper$1.invoke(ProtocolFilterWrapper.java:91) [dubbo-2.5.3.jar:2.5.3]
        at com.alibaba.dubbo.rpc.protocol.dubbo.filter.TraceFilter.invoke(TraceFilter.java:78) [dubbo-2.5.3.jar:2.5.3]
        at com.alibaba.dubbo.rpc.protocol.ProtocolFilterWrapper$1.invoke(ProtocolFilterWrapper.java:91) [dubbo-2.5.3.jar:2.5.3]
        at com.alibaba.dubbo.rpc.filter.ContextFilter.invoke(ContextFilter.java:60) [dubbo-2.5.3.jar:2.5.3]
        at com.alibaba.dubbo.rpc.protocol.ProtocolFilterWrapper$1.invoke(ProtocolFilterWrapper.java:91) [dubbo-2.5.3.jar:2.5.3]
        at com.alibaba.dubbo.rpc.filter.GenericFilter.invoke(GenericFilter.java:112) [dubbo-2.5.3.jar:2.5.3]
        at com.alibaba.dubbo.rpc.protocol.ProtocolFilterWrapper$1.invoke(ProtocolFilterWrapper.java:91) [dubbo-2.5.3.jar:2.5.3]
        at com.alibaba.dubbo.rpc.filter.ClassLoaderFilter.invoke(ClassLoaderFilter.java:38) [dubbo-2.5.3.jar:2.5.3]
        at com.alibaba.dubbo.rpc.protocol.ProtocolFilterWrapper$1.invoke(ProtocolFilterWrapper.java:91) [dubbo-2.5.3.jar:2.5.3]
        at com.alibaba.dubbo.rpc.filter.EchoFilter.invoke(EchoFilter.java:38) [dubbo-2.5.3.jar:2.5.3]
        at com.alibaba.dubbo.rpc.protocol.ProtocolFilterWrapper$1.invoke(ProtocolFilterWrapper.java:91) [dubbo-2.5.3.jar:2.5.3]
        at com.alibaba.dubbo.rpc.protocol.dubbo.DubboProtocol$1.reply(DubboProtocol.java:108) [dubbo-2.5.3.jar:2.5.3]
        at com.alibaba.dubbo.remoting.exchange.support.header.HeaderExchangeHandler.handleRequest(HeaderExchangeHandler.java:84) [dubbo-2.5.3.jar:2.5.3]
        at com.alibaba.dubbo.remoting.exchange.support.header.HeaderExchangeHandler.received(HeaderExchangeHandler.java:170) [dubbo-2.5.3.jar:2.5.3]
        at com.alibaba.dubbo.remoting.transport.DecodeHandler.received(DecodeHandler.java:52) [dubbo-2.5.3.jar:2.5.3]
        at com.alibaba.dubbo.remoting.transport.dispatcher.ChannelEventRunnable.run(ChannelEventRunnable.java:82) [dubbo-2.5.3.jar:2.5.3]
        at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1142) [na:1.8.0_131]
        at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:617) [na:1.8.0_131]
        at java.lang.Thread.run(Thread.java:748) [na:1.8.0_131]
Caused by: org.apache.ibatis.builder.BuilderException: Error evaluating expression 'projects != null and projects.size() > 0 '. Cause: org.apache.ibatis.ognl.MethodFailedException: Method "size" failed for object [u号租, 租号牛, 租号酷] [java.lang.IllegalAccessException: Class org.apache.ibatis.ognl.OgnlRuntime can not access a member of class java.util.Arrays$ArrayList with modifiers "public"]
        at org.apache.ibatis.scripting.xmltags.OgnlCache.getValue(OgnlCache.java:47) ~[mybatis-3.2.8.jar:3.2.8]
        at org.apache.ibatis.scripting.xmltags.ExpressionEvaluator.evaluateBoolean(ExpressionEvaluator.java:32) ~[mybatis-3.2.8.jar:3.2.8]
        at org.apache.ibatis.scripting.xmltags.IfSqlNode.apply(IfSqlNode.java:33) ~[mybatis-3.2.8.jar:3.2.8]
        at org.apache.ibatis.scripting.xmltags.MixedSqlNode.apply(MixedSqlNode.java:32) ~[mybatis-3.2.8.jar:3.2.8]
        at org.apache.ibatis.scripting.xmltags.TrimSqlNode.apply(TrimSqlNode.java:54) ~[mybatis-3.2.8.jar:3.2.8]
        at org.apache.ibatis.scripting.xmltags.MixedSqlNode.apply(MixedSqlNode.java:32) ~[mybatis-3.2.8.jar:3.2.8]
        at org.apache.ibatis.scripting.xmltags.TrimSqlNode.apply(TrimSqlNode.java:54) ~[mybatis-3.2.8.jar:3.2.8]
        at org.apache.ibatis.scripting.xmltags.MixedSqlNode.apply(MixedSqlNode.java:32) ~[mybatis-3.2.8.jar:3.2.8]
        at org.apache.ibatis.scripting.xmltags.DynamicSqlSource.getBoundSql(DynamicSqlSource.java:40) ~[mybatis-3.2.8.jar:3.2.8]
        at org.apache.ibatis.mapping.MappedStatement.getBoundSql(MappedStatement.java:278) ~[mybatis-3.2.8.jar:3.2.8]
        at com.github.pagehelper.PageInterceptor.intercept(PageInterceptor.java:83) ~[pagehelper-5.1.4.jar:na]
        at org.apache.ibatis.plugin.Plugin.invoke(Plugin.java:60) ~[mybatis-3.2.8.jar:3.2.8]
        at com.sun.proxy.$Proxy234.query(Unknown Source) ~[na:na]
        at org.apache.ibatis.session.defaults.DefaultSqlSession.selectList(DefaultSqlSession.java:108) ~[mybatis-3.2.8.jar:3.2.8]
        at org.apache.ibatis.session.defaults.DefaultSqlSession.selectList(DefaultSqlSession.java:102) ~[mybatis-3.2.8.jar:3.2.8]
        at sun.reflect.GeneratedMethodAccessor347.invoke(Unknown Source) ~[na:na]
        at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43) ~[na:1.8.0_131]
        at java.lang.reflect.Method.invoke(Method.java:498) ~[na:1.8.0_131]
        at org.mybatis.spring.SqlSessionTemplate$SqlSessionInterceptor.invoke(SqlSessionTemplate.java:358) ~[mybatis-spring-1.2.2.jar:1.2.2]
        ... 54 common frames omitted
Caused by: org.apache.ibatis.ognl.MethodFailedException: Method "size" failed for object [aaa,bbb,ccc]
        at org.apache.ibatis.ognl.OgnlRuntime.callAppropriateMethod(OgnlRuntime.java:837) ~[mybatis-3.2.8.jar:3.2.8]
        at org.apache.ibatis.ognl.ObjectMethodAccessor.callMethod(ObjectMethodAccessor.java:61) ~[mybatis-3.2.8.jar:3.2.8]
        at org.apache.ibatis.ognl.OgnlRuntime.callMethod(OgnlRuntime.java:860) ~[mybatis-3.2.8.jar:3.2.8]
        at org.apache.ibatis.ognl.ASTMethod.getValueBody(ASTMethod.java:73) ~[mybatis-3.2.8.jar:3.2.8]
        at org.apache.ibatis.ognl.SimpleNode.evaluateGetValueBody(SimpleNode.java:170) ~[mybatis-3.2.8.jar:3.2.8]
        at org.apache.ibatis.ognl.SimpleNode.getValue(SimpleNode.java:210) ~[mybatis-3.2.8.jar:3.2.8]
        at org.apache.ibatis.ognl.ASTChain.getValueBody(ASTChain.java:109) ~[mybatis-3.2.8.jar:3.2.8]
        at org.apache.ibatis.ognl.SimpleNode.evaluateGetValueBody(SimpleNode.java:170) ~[mybatis-3.2.8.jar:3.2.8]
        at org.apache.ibatis.ognl.SimpleNode.getValue(SimpleNode.java:210) ~[mybatis-3.2.8.jar:3.2.8]
        at org.apache.ibatis.ognl.ASTGreater.getValueBody(ASTGreater.java:49) ~[mybatis-3.2.8.jar:3.2.8]
        at org.apache.ibatis.ognl.SimpleNode.evaluateGetValueBody(SimpleNode.java:170) ~[mybatis-3.2.8.jar:3.2.8]
        at org.apache.ibatis.ognl.SimpleNode.getValue(SimpleNode.java:210) ~[mybatis-3.2.8.jar:3.2.8]
        at org.apache.ibatis.ognl.ASTAnd.getValueBody(ASTAnd.java:56) ~[mybatis-3.2.8.jar:3.2.8]
        at org.apache.ibatis.ognl.SimpleNode.evaluateGetValueBody(SimpleNode.java:170) ~[mybatis-3.2.8.jar:3.2.8]
        at org.apache.ibatis.ognl.SimpleNode.getValue(SimpleNode.java:210) ~[mybatis-3.2.8.jar:3.2.8]
        at org.apache.ibatis.ognl.Ognl.getValue(Ognl.java:333) ~[mybatis-3.2.8.jar:3.2.8]
        at org.apache.ibatis.ognl.Ognl.getValue(Ognl.java:310) ~[mybatis-3.2.8.jar:3.2.8]
        at org.apache.ibatis.scripting.xmltags.OgnlCache.getValue(OgnlCache.java:45) ~[mybatis-3.2.8.jar:3.2.8]
        ... 72 common frames omitted

赶紧查了下这个接口的调用情况，大部分没问题，偶尔冒了这么个错（还好还好）

根据堆栈反查错误位置，有点想不通，这里会有问题？那就只能翻源码了

源码分析

经过排查，ognl表达式中用到的方法，会通过反射，获取method，并缓存至静态变量中，所以，存在多线程状态中，产生并发问题，往下看

 这里是缓存方法的逻辑，org.apache.ibatis.ognl.OgnlRuntime#getMethods(java.lang.Class, boolean)感兴趣的可以自己看

 这里就是bug点，如果调用一旦多，存在A线程修改成true，还没调用方法，B线程就修改成false，此时调用失败，这不是个坑吗

 mybatis中一搜果然有这个issue：https://github.com/mybatis/mybatis-3/pull/384

 作者给的方案呢是升级mybatis。

开个玩笑，看看如何避免

总结

• 问题：如果需要ognl的对象的方法和类不是public，那么会存在并发问题
• 解决1：针对并发问题，升级Mybatis
• 解决2：Lists.newArrayList或者其他写法代替，反正看下，内部类是不是private

转自：https://juejin.cn/post/7264921613551730722