It looks to me as though there is a bug in AbstractConcurrentReadCache - the remove method (line 1699) will call addGroupMappings (line 1790) even if the oldEntry has no groups. Entry.getGroups() may return null if the Entry has no groups. The method addGroupMappings (line 1506) does not check whether its second parameter (a Set of group names) is null.

Either Entry.getGroups() should return an empty Set if there are no groups (instead of returning null), or the method AbstractConcurrentReadCache.addGroupMappings should check that the supplied Set is not null before attempting to iterate over its contents.


Stack trace:
2006-10-03 07:49:39,421 ERROR (StandardWrapperValve.java:260) - Servlet.service() for servlet ImageServlet threw exception
java.lang.NullPointerException
at com.opensymphony.oscache.base.algorithm.AbstractConcurrentReadCache.addGroupMappings(AbstractConcurrentReadCache.java:1508)
at com.opensymphony.oscache.base.algorithm.AbstractConcurrentReadCache.remove(AbstractConcurrentReadCache.java:1790)
at com.opensymphony.oscache.base.algorithm.AbstractConcurrentReadCache.put(AbstractConcurrentReadCache.java:1598)
at com.opensymphony.oscache.base.algorithm.AbstractConcurrentReadCache.put(AbstractConcurrentReadCache.java:863)
at com.opensymphony.oscache.base.Cache.putInCache(Cache.java:624)
at com.opensymphony.oscache.web.filter.CacheFilter.doFilter(CacheFilter.java:176)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:202)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:173)
at com.panoguide.filter.DomainFilter.doFilter(DomainFilter.java:51)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:202)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:173)
at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:213)
at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:178)
at org.apache.catalina.authenticator.AuthenticatorBase.invoke(AuthenticatorBase.java:432)
at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:126)
at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:105)
at org.apache.catalina.valves.AccessLogValve.invoke(AccessLogValve.java:541)
at org.apache.catalina.authenticator.SingleSignOn.invoke(SingleSignOn.java:367)
at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:107)
at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:148)
at org.apache.coyote.http11.Http11Processor.process(Http11Processor.java:868)
at org.apache.coyote.http11.Http11BaseProtocol$Http11ConnectionHandler.processConnection(Http11BaseProtocol.java:663)
at org.apache.tomcat.util.net.PoolTcpEndpoint.processSocket(PoolTcpEndpoint.java:527)
at org.apache.tomcat.util.net.LeaderFollowerWorkerThread.runIt(LeaderFollowerWorkerThread.java:80)
at org.apache.tomcat.util.threads.ThreadPool$ControlRunnable.run(ThreadPool.java:684)
at java.lang.Thread.run(Unknown Source)