How to mandate license expiry date

[Amit]

Hi!!!

The product which i am working on requires that it can be installed
and used for a stipulated number of days from the date of
installation. Also if its installed on one machine then uninstalling
and reinstalling it on the same takes care of counting the days from
first installation and not the latest installation. Hence system date
time check is not useful in this context. Thus like many software
evaluation copies it must work strictly on license validity periods.
Issues to be tackled are :

- Stamp the isntallation date somewhere such that it persists the
subsequent installtion and uninstallation of the software. - How to do
it?
- Check the days passed since installation. Here i must check with
the date of first installation which was stamped. - Accessing stamped
date is a problem?
- Most importantly changing the system date must not affect my
license expiry checks.

One solution which i found was to keep a registry key to store the
installation date which persists the uninstallation of the software.
But this i perceive shall involve JNI(I am not sure about it, Any
inputs would be of great help). I would prefer to avoid using JNI.

Please let me know if the problem i am facing needs more
clarification. Any inputs towards solution of this problem would be of
great help.

thanks and regards.
Amit Kapoor.

 

[Gerbrand van Dieijen]

Hi!!!

The product which i am working on requires that it can be installed
and used for a stipulated number of days from the date of
installation. Also if its installed on one machine then uninstalling
and reinstalling it on the same takes care of counting the days from
first installation and not the latest installation. Hence system date
time check is not useful in this context. Thus like many software
evaluation copies it must work strictly on license validity periods.
Issues to be tackled are :

Hello, there's some licencing and copy protection software for Java that
does this. If you search the web you'll find some.
Some are quite expensive, but other only cost around $1/200 which is not
very expensive considering the cost of implementing a good system your
self.
I'm evalution some my self at the time, currently for Windows only, but
later for a Java app too.