java.lang.NullPointerException
        at nl.tosec.laser.db.DatabaseController.getPreparedStatement(DatabaseController.java:48)
        at nl.tosec.laser.db.DatabaseController.getCategories(DatabaseController.java:61)
        at nl.tosec.laser.db.DatabaseManager.getCategories(DatabaseManager.java:58)
        at nl.tosec.laser.domain.CategoryManager.getCategories(CategoryManager.java:47)
        at nl.tosec.laser.struts.ListingActions.listCategories(ListingActions.java:93)
        at nl.tosec.laser.struts.ListingActions.execute(ListingActions.java:46)
        at org.apache.struts.action.RequestProcessor.processActionPerform(RequestProcessor.java:484)
        at org.apache.struts.action.RequestProcessor.process(RequestProcessor.java:274)
        at org.apache.struts.action.ActionServlet.process(ActionServlet.java:1482)
        at org.apache.struts.action.ActionServlet.doGet(ActionServlet.java:507)
        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:362)
        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.ApplicationDispatcher.invoke(ApplicationDispatcher.java:673)
        at org.apache.catalina.core.ApplicationDispatcher.processRequest(ApplicationDispatcher.java:464)
        at org.apache.catalina.core.ApplicationDispatcher.doForward(ApplicationDispatcher.java:399)
        at org.apache.catalina.core.ApplicationDispatcher.forward(ApplicationDispatcher.java:302)
        at org.apache.struts.action.RequestProcessor.doForward(RequestProcessor.java:1069)
        at org.apache.struts.action.RequestProcessor.internalModuleRelativeForward(RequestProcessor.java:1012)
        at org.apache.struts.action.RequestProcessor.processForward(RequestProcessor.java:582)
        at org.apache.struts.action.RequestProcessor.process(RequestProcessor.java:260)
        at org.apache.struts.action.ActionServlet.process(ActionServlet.java:1482)
        at org.apache.struts.action.ActionServlet.doGet(ActionServlet.java:507)
        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:362)
        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:214)
        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:825)
        at org.apache.coyote.http11.Http11Protocol$Http11ConnectionHandler.processConnection(Http11Protocol.java:738)
        at org.apache.tomcat.util.net.PoolTcpEndpoint.processSocket(PoolTcpEndpoint.java:526)
        at org.apache.tomcat.util.net.LeaderFollowerWorkerThread.runIt(LeaderFollowerWorkerThread.java:80)
        at org.apache.tomcat.util.threads.ThreadPool$ControlRunnable.run(ThreadPool.java:684)
        at java.lang.Thread.run(Thread.java:595)