edit hostconfig file on my mac

You can edit it using Terminal. Open terminal, type "cd /etc" (without the quotes), then type "sudo pico hostconfig" (without the quotes).

Make your edits and hit control-x, type "y" when it asks you to save changes, and hit return when it asks for the filename (it'll have "hostconfig" already there as the filename).

[WebContainer : 7] [ERROR] [] [org.apache.wicket.RequestCycle] submitted http post value [radio124] for RadioGroup component [2:form:tabs:panel:crumbPanel:TestRadioGroup] is illegal because it does not contain relative path to a Radio componnet. Due to this the RadioGroup component cannot resolve the selected Radio component pointed to by the illegal value. A possible reason is that componment hierarchy changed between rendering and form submission.

[WebContainer : 7] [ERROR] [] [org.apache.wicket.RequestCycle] submitted http post value [radio124] for RadioGroup component [2:form:tabs:panel:crumbPanel:TestRadioGroup] is illegal because it does not contain relative path to a Radio componnet. Due to this the RadioGroup component cannot resolve the selected Radio component pointed to by the illegal value. A possible reason is that componment hierarchy changed between rendering and form submission.

org.apache.wicket.WicketRuntimeException: submitted http post value [radio124] for RadioGroup component [2:form:tabs:panel:crumbPanel:TestRadioGroup] is illegal because it does not contain relative path to a Radio componnet. Due to this the RadioGroup component cannot resolve the selected Radio component pointed to by the illegal value. A possible reason is that componment hierarchy changed between rendering and form submission.


This issue occurred as My Page had two panels with same component hierarchy. i.e. the child panels was dynamically replaced with each other having a radio group the same wicket id TestRadioGroup.

Apache Wicket WicketNotSerializableException: Unable to serialize clas

This is a typical Wicket problem which occurs on clicking browser back button and clicking any stale link on the page.

DEBUG - Rendering raw markup
DEBUG - Rendered [Page class = com..web.appointments.page.AppointmentSchedulerPage, id = 3, version = 0]
DEBUG - End render [Page class = com.project.web.appointments.page.AppointmentSchedulerPage, id = 3, version = 0]
DEBUG - ending request for page [Page class = com.project.web.appointments.page.AppointmentSchedulerPage, id = 3, version = 0], request [method = GET, protocol = HTTP/1.1, requestURL = http://localhost:8080/project-1.0/appointmentScheduler, contentType = null, contentLength = -1, contextPath = /project-1.0, pathInfo = null, requestURI = /project-1.0/appointmentScheduler, servletPath = /appointmentScheduler, pathTranslated = null]
DEBUG - ending request for page [Page class = com.project.web.appointments.page.AppointmentSchedulerPage, id = 3, version = 0], request [method = GET, protocol = HTTP/1.1, requestURL = http://localhost:8080/project-1.0/appointmentScheduler, contentType = null, contentLength = -1, contextPath = /project-1.0, pathInfo = null, requestURI = /project-1.0/appointmentScheduler, servletPath = /appointmentScheduler, pathTranslated = null]
ERROR - Error serializing object class com.project.web.appointments.page.AppointmentSchedulerPage [object=[Page class = com.project.web.appointments.page.AppointmentSchedulerPage, id = 3, version = 0]]
org.apache.wicket.util.io.SerializableChecker$WicketNotSerializableException: Unable to serialize class: com.project.service.appointments.dataobject.projectAppointment
Field hierarchy is:
3 [class=com.project.web.appointments.page.AppointmentSchedulerPage, path=3]
private java.lang.Object org.apache.wicket.MarkupContainer.children [class=com.project.web.appointments.panel.projectAppointmentSchedulerPanel, path=3:projectAppointmentSchedulerPanel]
private java.lang.Object org.apache.wicket.MarkupContainer.children [class=com.project.web.appointments.form.AppointmentSchedulerForm, path=3:projectAppointmentSchedulerPanel:appointmentSchedulerForm]
java.lang.Object org.apache.wicket.Component.data [class=org.apache.wicket.model.CompoundPropertyModel]
private java.lang.Object org.apache.wicket.model.CompoundPropertyModel.target [class=com.project.service.appointments.dataobject.projectAppointment] <----- data-blogger-escaped-br="" data-blogger-escaped-field="" data-blogger-escaped-is="" data-blogger-escaped-not="" data-blogger-escaped-serializable="" data-blogger-escaped-that=""> at org.apache.wicket.util.io.SerializableChecker.check(SerializableChecker.java:346)
at org.apache.wicket.util.io.SerializableChecker.checkFields(SerializableChecker.java:615)
at org.apache.wicket.util.io.SerializableChecker.check(SerializableChecker.java:538)
at org.apache.wicket.util.io.SerializableChecker.checkFields(SerializableChecker.java:615)
at org.apache.wicket.util.io.SerializableChecker.check(SerializableChecker.java:538)
at org.apache.wicket.util.io.SerializableChecker.checkFields(SerializableChecker.java:615)
at org.apache.wicket.util.io.SerializableChecker.check(SerializableChecker.java:538)
at org.apache.wicket.util.io.SerializableChecker.checkFields(SerializableChecker.java:615)
at org.apache.wicket.util.io.SerializableChecker.check(SerializableChecker.java:538)
at org.apache.wicket.util.io.SerializableChecker.writeObjectOverride(SerializableChecker.java:684)
at java.io.ObjectOutputStream.writeObject(ObjectOutputStream.java:322)
at org.apache.wicket.util.io.IObjectStreamFactory$DefaultObjectStreamFactory$2.writeObjectOverride(IObjectStreamFactory.java:129)
at java.io.ObjectOutputStream.writeObject(ObjectOutputStream.java:322)
at org.apache.wicket.util.lang.Objects.objectToByteArray(Objects.java:1120)
at org.apache.wicket.protocol.http.pagestore.AbstractPageStore.serializePage(AbstractPageStore.java:203)
at org.apache.wicket.protocol.http.pagestore.DiskPageStore.storePage(DiskPageStore.java:840)
at org.apache.wicket.protocol.http.SecondLevelCacheSessionStore$SecondLevelCachePageMap.put(SecondLevelCacheSessionStore.java:332)
at org.apache.wicket.Session.requestDetached(Session.java:1404)
at org.apache.wicket.RequestCycle.detach(RequestCycle.java:1176)
at org.apache.wicket.RequestCycle.steps(RequestCycle.java:1454)
at org.apache.wicket.RequestCycle.request(RequestCycle.java:545)
at org.apache.wicket.protocol.http.WicketFilter.doGet(WicketFilter.java:468)
at org.apache.wicket.protocol.http.WicketFilter.doFilter(WicketFilter.java:301)
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:233)
at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:191)
at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:127)
at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:102)
at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:109)
at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:298)
at org.apache.coyote.http11.Http11Processor.process(Http11Processor.java:857)
at org.apache.coyote.http11.Http11Protocol$Http11ConnectionHandler.process(Http11Protocol.java:588)
at org.apache.tomcat.util.net.JIoEndpoint$Worker.run(JIoEndpoint.java:489)
at java.lang.Thread.run(Thread.java:637)
Caused by: java.io.NotSerializableException: com.project.service.appointments.dataobject.projectAppointment
at java.io.ObjectOutputStream.writeObject0(ObjectOutputStream.java:1156)
at java.io.ObjectOutputStream.defaultWriteFields(ObjectOutputStream.java:1509)
at java.io.ObjectOutputStream.writeSerialData(ObjectOutputStream.java:1474)
at java.io.ObjectOutputStream.writeOrdinaryObject(ObjectOutputStream.java:1392)
at java.io.ObjectOutputStream.writeObject0(ObjectOutputStream.java:1150)
at java.io.ObjectOutputStream.defaultWriteFields(ObjectOutputStream.java:1509)
at java.io.ObjectOutputStream.defaultWriteObject(ObjectOutputStream.java:416)
at org.apache.wicket.Component.writeObject(Component.java:4447)
at sun.reflect.GeneratedMethodAccessor30.invoke(Unknown Source)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:25)
at java.lang.reflect.Method.invoke(Method.java:597)
at java.io.ObjectStreamClass.invokeWriteObject(ObjectStreamClass.java:945)
at java.io.ObjectOutputStream.writeSerialData(ObjectOutputStream.java:1461)
at java.io.ObjectOutputStream.writeOrdinaryObject(ObjectOutputStream.java:1392)
at java.io.ObjectOutputStream.writeObject0(ObjectOutputStream.java:1150)
at java.io.ObjectOutputStream.defaultWriteFields(ObjectOutputStream.java:1509)
at java.io.ObjectOutputStream.writeSerialData(ObjectOutputStream.java:1474)
at java.io.ObjectOutputStream.writeOrdinaryObject(ObjectOutputStream.java:1392)
at java.io.ObjectOutputStream.writeObject0(ObjectOutputStream.java:1150)
at java.io.ObjectOutputStream.defaultWriteFields(ObjectOutputStream.java:1509)
at java.io.ObjectOutputStream.writeSerialData(ObjectOutputStream.java:1474)
at java.io.ObjectOutputStream.writeOrdinaryObject(ObjectOutputStream.java:1392)
at java.io.ObjectOutputStream.writeObject0(ObjectOutputStream.java:1150)
at java.io.ObjectOutputStream.writeObject(ObjectOutputStream.java:326)
at org.apache.wicket.util.io.IObjectStreamFactory$DefaultObjectStreamFactory$2.writeObjectOverride(IObjectStreamFactory.java:121)
... 23 more
DEBUG - Getting page [path = 2:projectProfilePanel:AptmntCalendarPanel:sAppointmentList:1:sAppointmentTimeFrameList:4:sAppointmentLink, versionNumber = 0]
DEBUG - setting request target to [BookmarkablePageRequestTarget@-371790702 pageClass=org.apache.wicket.markup.html.pages.PageExpiredErrorPage]
DEBUG - update: Session not dirty.
DEBUG - Redirecting to ?wicket:bookmarkablePage=:org.apache.wicket.markup.html.pages.PageExpiredErrorPage
DEBUG - Add homePageLink to [Page class = org.apache.wicket.markup.html.pages.PageExpiredErrorPage, id = 4, version = 0]
DEBUG - Begin render [Page class = org.apache.wicket.markup.html.pages.PageExpiredErrorPage, id = 4, version = 0]


=========================================
Solution

Override the following method in your page class. It would surely resolve the problem :

/**
* Confgured to clear the cache and re-render the page every time user request for it.
* This is used to overcome the browser back button problem.
*/
@Override
protected void configureResponse() {
super.configureResponse();

final WebResponse response = getWebRequestCycle().getWebResponse();
response.setHeader("Cache-Control", "no-cache, max-age=0, must-revalidate, no-store");
}

HTML CSS - Scrollbar to be added to a div

Just came across a requirement where I had to use the scroll bar with a div.

I used the following to put the same:

<div style="overflow:auto;height:200px;width:500px;">
-----
-----
-----
</div>

This works fine and looks cool.