The following message is a courtesy copy of an article that has been posted to comp.lang.java.databases as well.
I'm cc'ing this reply to derby-user@db.apache.org, since not many derby people follow this newsgroup. Harri Pesonen <[EMAIL PROTECTED]> writes: > I get the following error (sometimes) when I use DataSet<sometype> > with Derby 10.2.1.0 and JDK6 b98: > > java.sql.SQLRuntimeException: Cannot store DataSet instance to WeakHashMap > at com.sun.sql.QueryObject.registerDataSet(QueryObject.java:1306) > at com.sun.sql.QueryObject.getQueryImpl(QueryObject.java:767) > at com.sun.sql.QueryObject.access$000(QueryObject.java:26) > at com.sun.sql.QueryObject$1.run(QueryObject.java:229) > at java.security.AccessController.doPrivileged(Native Method) > at com.sun.sql.QueryObject.invoke(QueryObject.java:224) > at $Proxy5.system_Prefs_get(Unknown Source) > at Kahvi.Kahvi.get_sys_pref(Kahvi.java:896) > at Kahvi.Kahvi.get_sys_pref(Kahvi.java:892) > at Kahvi.Kahvi.cache_filename(Kahvi.java:2627) > at Kahvi.Kahvi.servletThumb(Kahvi.java:326) > at Kahvi.thumb.processKahvi(thumb.java:23) > at Kahvi.KahviServlet.processRequest(KahviServlet.java:66) > at Kahvi.KahviServlet.doGet(KahviServlet.java:88) > at javax.servlet.http.HttpServlet.service(HttpServlet.java:689) > at javax.servlet.http.HttpServlet.service(HttpServlet.java:802) > at > org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:252) > at > org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:173) > at > org.netbeans.modules.web.monitor.server.MonitorFilter.doFilter(MonitorFilter.java:368) > at > org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:202) > at > org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:173) > at > org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:213) > at > org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:178) > at > org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:126) > at > org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:105) > at > org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:107) > at > org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:148) > at > org.apache.coyote.http11.Http11Processor.process(Http11Processor.java:869) > at > org.apache.coyote.http11.Http11BaseProtocol$Http11ConnectionHandler.processConnection(Http11BaseProtocol.java:664) > 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$ControlRunnable.run(ThreadPool.java:684) > at java.lang.Thread.run(Thread.java:619) > Caused by: java.lang.NullPointerException > at com.sun.sql.DataSetImpl$DataSetItr.<init>(DataSetImpl.java:1759) > at > com.sun.sql.DataSetImpl$DataSetListIterator.<init>(DataSetImpl.java:1846) > at com.sun.sql.DataSetImpl.listIterator(DataSetImpl.java:1628) > at java.util.AbstractList.equals(AbstractList.java:503) > at java.util.WeakHashMap.eq(WeakHashMap.java:259) > at java.util.WeakHashMap.put(WeakHashMap.java:406) > at com.sun.sql.QueryObject.registerDataSet(QueryObject.java:1304) > ... 32 more -- dt However, experience shows that for many people and many applications a dose of paranoia is reasonable - Bjarne Stroustrup
