public static final class TaglibFactory.WebInfPerLibJarMetaInfTldSource
extends TaglibFactory.MetaInfTldSource

To search TLD-s under sevletContext:/WEB-INF/lib/*.{jar,zip}/META-INF/**/*.tld, as requested by the JSP specification. Note that these also used to be in the classpath, so it's redundant to use this together with a sufficiently permissive TaglibFactory.ClasspathMetaInfTldSource.