Tomcat 8.5 el-API上的Spring迁移4.3到5错误

在Tomcat 8.5上使用Spring Boot初始化器将Spring4.3升级到5时，我们开始收到异常：

2021-06-06 12:37:50,482 DEBUG [background-preinit] messageinterpolation.ResourceBundleMessageInterpolator (ResourceBundleMessageInterpolator.java:220) - Failed to load expression factory via classloader ParallelWebappClassLoader
  context: ROOT
  delegate: false
----------> Parent Classloader:
java.net.URLClassLoader@76f856a8

javax.el.ELException: Unable to find ExpressionFactory of type [# Licensed to the Apache Software Foundation (ASF) under one or more]
        at javax.el.ExpressionFactory.newInstance(ExpressionFactory.java:154) ~[el-api.jar:3.0.FR]
        at javax.el.ExpressionFactory.newInstance(ExpressionFactory.java:93) ~[el-api.jar:3.0.FR]
        at org.hibernate.validator.messageinterpolation.ResourceBundleMessageInterpolator.canLoadExpressionFactory(ResourceBundleMessageInterpolator.java:216) [hibernate-validator-6.2.0.Final.jar:6.2.0.Final]
        at org.hibernate.validator.messageinterpolation.ResourceBundleMessageInterpolator.buildExpressionFactory(ResourceBundleMessageInterpolator.java:170) [hibernate-validator-6.2.0.Final.jar:6.2.0.Final]
        at org.hibernate.validator.messageinterpolation.ResourceBundleMessageInterpolator.<init>(ResourceBundleMessageInterpolator.java:94) [hibernate-validator-6.2.0.Final.jar:6.2.0.Final]
        at org.hibernate.validator.internal.engine.AbstractConfigurationImpl.getDefaultMessageInterpolator(AbstractConfigurationImpl.java:573) [hibernate-validator-6.2.0.Final.jar:6.2.0.Final]
        at org.hibernate.validator.internal.engine.AbstractConfigurationImpl.getDefaultMessageInterpolatorConfiguredWithClassLoader(AbstractConfigurationImpl.java:822) [hibernate-validator-6.2.0.Final.jar:6.2.0.Final]
        at org.hibernate.validator.internal.engine.AbstractConfigurationImpl.getMessageInterpolator(AbstractConfigurationImpl.java:483) [hibernate-validator-6.2.0.Final.jar:6.2.0.Final]
        at org.hibernate.validator.internal.engine.ValidatorFactoryImpl.<init>(ValidatorFactoryImpl.java:153) [hibernate-validator-6.2.0.Final.jar:6.2.0.Final]
        at org.hibernate.validator.HibernateValidator.buildValidatorFactory(HibernateValidator.java:38) [hibernate-validator-6.2.0.Final.jar:6.2.0.Final]
        at org.hibernate.validator.internal.engine.AbstractConfigurationImpl.buildValidatorFactory(AbstractConfigurationImpl.java:451) [hibernate-validator-6.2.0.Final.jar:6.2.0.Final]
        at org.springframework.boot.autoconfigure.BackgroundPreinitializer$ValidationInitializer.run(BackgroundPreinitializer.java:149) [spring-boot-autoconfigure-2.5.0.jar:2.5.0]
        at org.springframework.boot.autoconfigure.BackgroundPreinitializer$1.runSafely(BackgroundPreinitializer.java:111) [spring-boot-autoconfigure-2.5.0.jar:2.5.0]
        at org.springframework.boot.autoconfigure.BackgroundPreinitializer$1.run(BackgroundPreinitializer.java:102) [spring-boot-autoconfigure-2.5.0.jar:2.5.0]
        at java.lang.Thread.run(Thread.java:748) [?:1.8.0_151]
Caused by: java.lang.ClassNotFoundException: # Licensed to the Apache Software Foundation (ASF) under one or more
        at org.apache.catalina.loader.WebappClassLoaderBase.loadClass(WebappClassLoaderBase.java:1358) ~[catalina.jar:8.5.50]
        at org.apache.catalina.loader.WebappClassLoaderBase.loadClass(WebappClassLoaderBase.java:1180) ~[catalina.jar:8.5.50]
        at javax.el.ExpressionFactory.newInstance(ExpressionFactory.java:147) ~[el-api.jar:3.0.FR]
        ... 14 more

el-api jar取自tomcat/lib，我们还将el-API版本从2更改为3，但仍抛出异常

是否有此例外的已知解决方案？

可以忽略它吗？

我发现related bug无法修复

EPEL EL6于2020-11-30更改为报废(EOL)状态。埃佩尔E6是 不再维护，这意味着它将不会再收到任何 安全或错误修复更新。因此，我们将关闭此错误。

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解决方案

您偶然发现了错误64097：未跳过META-INF/services/javax.el.ExpressionFactory文件中的注释，因此出现奇怪的错误。

此问题已在Tomcat版本8.5.51和9.0.31中修复。