[Wicket-user] DataTable and IDataProvider question

Frank Silbermann Fri, 24 Mar 2006 06:45:21 -0800

I am working with a database that is kind of strange. Someone provides a new table with each day’s data. Thus, the database can cause an SQLException as a normal result for the use case where the user requests data that hasn’t been produced yet.

When my “Iterator IDataprovider.iterate(int first, int count)” method is called and I go to the database, I would like to handle the SQLException to call “void Component.setResponsePage( Class.responsePage)" to tell the user what has happened, passing in PageParameters to enable the user to continue.

It seems that DataTable does not like me jumping out of the “iterate(first,count)” method like that. It tries to set the ResponsePage to the Wicket error page, which causes a serious failure saying that one cannot set the ResponsePage twice.

What are my options for solving this problem?

Is it simply a matter of making my “iterate(first,count) return an empty iterator to satisfy the DataTable caller before my “setResponsePage()” can take effect?

Here is the relevant section from the Tomcat logfile:

Mar 24, 2006 8:11:03 AM org.apache.catalina.core.ApplicationContext log

INFO: org.apache.webapp.balancer.BalancerFilter: init(): ruleChain: [org.apache.webapp.balancer.RuleChain: [org.apache.webapp.balancer.rules.URLStringMatchRule: Target string: News / Redirect URL: http://www.cnn.com], [org.apache.webapp.balancer.rules.RequestParameterRule: Target param name: paramName / Target param value: paramValue / Redirect URL: http://www.yahoo.com], [org.apache.webapp.balancer.rules.AcceptEverythingRule: Redirect URL: http://jakarta.apache.org]]

Mar 24, 2006 8:11:03 AM org.apache.catalina.core.ApplicationContext log

INFO: ContextListener: contextInitialized()

Mar 24, 2006 8:11:03 AM org.apache.catalina.core.ApplicationContext log

INFO: SessionListener: contextInitialized()

Mar 24, 2006 8:11:10 AM org.apache.catalina.core.ApplicationContext log

INFO: ContextListener: contextInitialized()

Mar 24, 2006 8:11:10 AM org.apache.catalina.core.ApplicationContext log

INFO: SessionListener: contextInitialized()

Mar 24, 2006 8:11:20 AM org.apache.catalina.core.StandardWrapperValve invoke

SEVERE: Servlet.service() for servlet MEM_Application threw exception

wicket.WicketRuntimeException: Internal Error: Could not render error page class wicket.markup.html.pages.InternalErrorPage

at wicket.request.compound.DefaultExceptionResponseStrategy.respond(DefaultExceptionResponseStrategy.java:106)

at wicket.request.compound.AbstractCompoundRequestCycleProcessor.respond(AbstractCompoundRequestCycleProcessor.java:76)

at wicket.RequestCycle.step(RequestCycle.java:971)

at wicket.RequestCycle.steps(RequestCycle.java:1005)

at wicket.RequestCycle.request(RequestCycle.java:451)

at wicket.protocol.http.WicketServlet.doGet(WicketServlet.java:212)

at wicket.protocol.http.WicketServlet.doPost(WicketServlet.java:250)

at javax.servlet.http.HttpServlet.service(HttpServlet.java:709)

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.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:856)

at org.apache.coyote.http11.Http11Protocol$Http11ConnectionHandler.processConnection(Http11Protocol.java:744)

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:595)

Caused by: wicket.WicketRuntimeException: Already redirecting to '/MEMSpssWebModule/mem?wicket:interface=:0:1:'. Cannot redirect more than once

at wicket.protocol.http.BufferedWebResponse.redirect(BufferedWebResponse.java:88)

at wicket.protocol.http.WebRequestCycle.redirectTo(WebRequestCycle.java:205)

at wicket.request.target.component.PageRequestTarget.respond(PageRequestTarget.java:60)

at wicket.request.compound.DefaultResponseStrategy.respond(DefaultResponseStrategy.java:49)

at wicket.request.compound.AbstractCompoundRequestCycleProcessor.respond(AbstractCompoundRequestCycleProcessor.java:66)

at wicket.RequestCycle.respond(RequestCycle.java:877)

at wicket.RequestCycle.step(RequestCycle.java:946)

... 20 more