Basically the jsp or java class has to be run and it has to check start date and end date for each record in the database
and generate the following emails.
(Run Daily once) end date - curr date < 7 Email Type A
(Run Weekly once) end date - curr date <30 Email Type B
(Run Monthly Once) end date - curr date <60 Email Type C
(Run Once in last 3 months) end date - curr date <90 Email Type D
The operating system used is Windows, so cron is not an option.