null pointer exception

[chramprasad]

public ActionForward edit(ActionMapping mapping, ActionForm form,
HttpServletRequest request, HttpServletResponse response)
throws Exception {
MissionForm missionForm = (MissionForm) form;

String strMissionId = InsEncr.getSingleton().decrypt(missionForm.getMiss ionId().toString());

Long userEntityTypeId = getUserEntityTypeId(request);
String strUserEntityTypeId = String.valueOf(userEntityTypeId);
String actionForward = PARAM_EDIT_MISSION;
if (!StringUtil.isEmpty(strMissionId)) {
actionForward = handleEditWhenMissionIsNotNew(strMissionId, mapping, request);
} else if (Constants.EntityType.NATIONAL.equals(strUserEntit yTypeId) ||
Constants.EntityType.SECTORIAL.equals(strUserEntit yTypeId)) {
actionForward = handleAddMissionWhenEntityIsNationalOrSectorial(re quest);
}

return mapping.findForward(actionForward);

}

In the above when i execute to add a new item its throwing exception null pointer exception
String strMissionId = InsEncr.getSingleton().decrypt(missionForm.getMiss ionId().toString());

so anyone can get the solution so that it shouldnot throw exception

advance thanks

[Banfa]

I would guess that the most likely problem is that form is not a MissionForm and so when you cast it (which is quite a bad idea) to MissionForm and then try to call the GetMissionId member that member does not exist for form causing an exception.

Assuming this is C++ you may wish to consider using dynamic_cast to cast your form ensuring that it is actually possible to do it (and catch the exception that happens if it isn't).

[chramprasad]

I would guess that the most likely problem is that form is not a MissionForm and so when you cast it (which is quite a bad idea) to MissionForm and then try to call the GetMissionId member that member does not exist for form causing an exception.

Assuming this is C++ you may wish to consider using dynamic_cast to cast your form ensuring that it is actually possible to do it (and catch the exception that happens if it isn't).

its missionform and missionid is also present but like when executing its taking null value to missionid and displaying nullpointerexception.only java

[chramprasad]

its missionform and missionid is also present but like when executing its taking null value to missionid and displaying nullpointerexception.only java