Dear chris, I will take care about it and update it accordingly
Regards, Koti On Wed, May 3, 2023 at 12:02 PM Christopher Schultz < ch...@christopherschultz.net> wrote: > 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 > >
