The error has been triggered by using classpath scanning in Spring, but can be reproduced independently.

The code in the servlet listed below does virtually the same thing as the VFSResourcePatternResolver:

public class BasicServlet extends HttpServlet{

@Override
protected void doGet(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
ClassLoader classLoader = Thread.currentThread().getContextClassLoader();
Enumeration<URL> urls = classLoader.getResources("");
StringBuffer buffer = new StringBuffer();
while (urls.hasMoreElements())

{ URL url = urls.nextElement(); VirtualFile file = VFS.getRoot(url); buffer.append(file.getPathName() + "\n"); }

new PrintWriter(resp.getOutputStream()).println(buffer.toString());
}
}

Trying to access the servlet results in an error when one URL is converted to a VirtualFile by VFS.getRoot(), and here is the resulting exception. The URL that triggers the error differs if the test is repeated.

00:45:44,380 ERROR [[resource-servlet]] Servlet.service() for servlet resource-servlet threw exception
java.io.IOException: Child not found opt/jboss/jboss-5.0.1.GA/server/default/deployers/jbossws.deployer/policy.jar/ for MemoryContextHandler@555514482[path= context=vfsmemory://3j011-j4xs2m-fuc3y7a8-1-fuc3yl41-9 real=vfsmemory://3j011-j4xs2m-fuc3y7a8-1-fuc3yl41-9], available children: []
at org.jboss.virtual.plugins.registry.DefaultVFSRegistry.findHandler(DefaultVFSRegistry.java:109)
at org.jboss.virtual.plugins.registry.DefaultVFSRegistry.getFile(DefaultVFSRegistry.java:88)
at org.jboss.virtual.plugins.registry.DefaultVFSRegistry.getFile(DefaultVFSRegistry.java:121)
at org.jboss.virtual.VFS.getRoot(VFS.java:276)
at BasicServlet.doGet(BasicServlet.java:22)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:617)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:717)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:290)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:206)
at org.jboss.web.tomcat.filters.ReplyHeaderFilter.doFilter(ReplyHeaderFilter.java:96)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:235)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:206)
at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:235)
at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:191)
at org.jboss.web.tomcat.security.SecurityAssociationValve.invoke(SecurityAssociationValve.java:190)
at org.jboss.web.tomcat.security.JaccContextValve.invoke(JaccContextValve.java:92)
at org.jboss.web.tomcat.security.SecurityContextEstablishmentValve.process(SecurityContextEstablishmentValve.java:126)
at org.jboss.web.tomcat.security.SecurityContextEstablishmentValve.invoke(SecurityContextEstablishmentValve.java:70)
at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:127)
at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:102)
at org.jboss.web.tomcat.service.jca.CachedConnectionValve.invoke(CachedConnectionValve.java:158)
at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:109)
at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:330)
at org.apache.coyote.http11.Http11Processor.process(Http11Processor.java:829)
at org.apache.coyote.http11.Http11Protocol$Http11ConnectionHandler.process(Http11Protocol.java:601)
at org.apache.tomcat.util.net.JIoEndpoint$Worker.run(JIoEndpoint.java:447)
at java.lang.Thread.run(Thread.java:619)