Hi Chris, Fixing the parent in this project is quite easy, if the OSGi bundle.getResources returns null then return emptyEnumeration instead of the direct result of the call but generally speaking this is a valid statement but I guess Tomcat can await some other hit of this issue to push forward a fix it since this one is very trivial to do in the failing project ([1]).
[1] https://github.com/CodeGerm/osgi-server/blob/master/plugins/org.cg.dao.webcontainer/src/org/cg/dao/webcontainer/tomcat/DaoClassLoader.java#L132 Romain Manni-Bucau @rmannibucau <https://twitter.com/rmannibucau> | Blog <https://rmannibucau.metawerx.net/> | Old Blog <http://rmannibucau.wordpress.com> | Github <https://github.com/rmannibucau> | LinkedIn <https://www.linkedin.com/in/rmannibucau> | Book <https://www.packtpub.com/application-development/java-ee-8-high-performance> Le mer. 3 mai 2023 à 21:02, Christopher Schultz < ch...@christopherschultz.net> a écrit : > All, > > Please check this thread for full details: > https://lists.apache.org/thread/of5ozg43zyk729cg311dktjcv3swct26 > > Briefly, a user reported this NPE: > > Apr 29, 2023 5:41:32 PM org.apache.catalina.core.StandardContext > listenerStart > SEVERE: Exception sending context initialized event to listener instance > of class [org.springframework.web.context.ContextLoaderListener] > java.lang.NullPointerException > at > > org.apache.catalina.loader.WebappClassLoaderBase$CombinedEnumeration.inc(WebappClassLoaderBase.java:2775) > at > > org.apache.catalina.loader.WebappClassLoaderBase$CombinedEnumeration.hasMoreElements(WebappClassLoaderBase.java:2760) > at > > org.apache.commons.logging.LogFactory.getConfigurationFile(LogFactory.java:1366) > at > org.apache.commons.logging.LogFactory.getFactory(LogFactory.java:453) > at org.apache.commons.logging.LogFactory.getLog(LogFactory.java:655) > > Mark introduced the CombinedEnumeration in > > https://github.com/apache/tomcat/commit/fdd35009ead6365cbae84008e63356d6ab88ed40 > to merge the resources from the parent ClassLoader with the > WebappClassLoader(Base). His code looks sound to me, but it can expose > what I think of as a bug in the ClassLoader being used as the parent. > > ClassLoader.getResources is documented to return an empty Enumeration if > there are no matching resources, but in this case, the ClassLoader is > returning null. > > WebappClassLoaderBase assumes that the parent ClassLoader is following > the rules and so grabs the resources from both itself and the parent and > combines them using CombinedEnumeration. > > Here is a patch that will fix that: > > diff --git a/java/org/apache/catalina/loader/WebappClassLoaderBase.java > b/java/org/apache/catalina/loader/WebappClassLoaderBase.java > index aa747a5873..6f98f6e413 100644 > --- a/java/org/apache/catalina/loader/WebappClassLoaderBase.java > +++ b/java/org/apache/catalina/loader/WebappClassLoaderBase.java > @@ -1121,7 +1121,9 @@ public abstract class WebappClassLoaderBase > extends URLClassLoader > // Enumerations are combined depends on how delegation is > configured > boolean delegateFirst = delegate || filter(name, false); > > - if (delegateFirst) { > + if(null == parentResources) { > + return localResources; > + } else if (delegateFirst) { > return new CombinedEnumeration(parentResources, > localResources); > } else { > return new CombinedEnumeration(localResources, > parentResources); > > But my question is whether or not this is something that Tomcat should > be working-around. IMO the parent ClassLoader is buggy and should be > fixed, but it may be difficult or impossible to fix the parent, so it > may be worth it. > > We could even log it including the class name of the offending ClassLoader. > > WDYT? > > -chris > > --------------------------------------------------------------------- > To unsubscribe, e-mail: dev-unsubscr...@tomcat.apache.org > For additional commands, e-mail: dev-h...@tomcat.apache.org > >
