I have developed some application software in Java language that Iplan to distribute to end users as a trialware.How can I make the Java app work for a limited time. Say for a monthA note to Andrew: This is the feature I tried to implement withupdating a file contained in the Jar file

Dexter wrote:>I have developed some application software in Java language that I>plan to distribute to end users as a trialware.>>How can I make the Java app work for a limited time. Say for a monthOh, that is horrible.  *>A note to Andrew: This is the feature I tried to implement with>updating a file contained in the Jar file* To be honest (OK blunt), this is not something I am likely to expend time helping with.-- Andrew Thompsonhttp://www.athompson.info/andrew/Message posted via http://www.javakb.com

In article <1193306844.096975.90050@o80g2000hse.googlegroups.com>,
Dexter  <yousaf.asad@gmail.com> wrote:
>I have developed some application software in Java language that I
>plan to distribute to end users as a trialware.
>
>How can I make the Java app work for a limited time. Say for a month

Have it call your server every time it launches (and once every 24
hours if left to run for that long) and perform some hard-to-spoof
communication whereby your server tells the app whether it should
function or not. Of course, this requires your users to always be
online when using the app.

>A note to Andrew: This is the feature I tried to implement with
>updating a file contained in the Jar file

You cannot really achieve this by checking local data and doing local
actions. The user can easily set back his clock, run the app in a VM,
etc., which will tend to screw up your checking.


Note: it is probably a bad idea to do any of the above. It will
introduce entirely new catastrophic points of failure and even if you
get the mechanism to work 100%, it is still going to alienate a number
of potential customers who are really pissed that it just suddenly
stopped working after a month. Even users who don't pay for your app
tend to contribute to your earnings by spreading the word to their
friends, some of whom will pay - /unless/ said non-payers get burned
by sudden deactivation in which case they will instead be telling
their friends how much your software sucks.

But, if you have extensively researched your market and determined
that product deactivation isn't going to have such negative effects on
your target audience, server-based (and probably registration key
based) authentication is the way to go.

Cheers,
	Bent D
-- 
Bent Dalager - bcd@pvv.org - http://www.pvv.org/~bcd
                                    powered by emacs

Bent C Dalager wrote:....> > Note: it is probably a bad idea to do any of the above. It will> introduce entirely new catastrophic points of failure and even if you> get the mechanism to work 100%, it is still going to alienate a number> of potential customers who are really pissed that it just suddenly> stopped working after a month. Even users who don't pay for your app> tend to contribute to your earnings by spreading the word to their> friends, some of whom will pay - /unless/ said non-payers get burned> by sudden deactivation in which case they will instead be telling> their friends how much your software sucks.....Deactivation does not need to be sudden. I've used trial ware thatshowed a dialog each time it started pointing out that it is trialsoftware and saying how many days remain.Patricia

On Thu, 25 Oct 2007 03:07:24 -0700, Dexter <yousaf.asad@gmail.com>
wrote, quoted or indirectly quoted someone who said :

>How can I make the Java app work for a limited time. Say for a month

see http://mindprod.com/jgloss/installer.html

A very simple scheme just pokes the install date into the registry
using the Preferences mechanism.

See http://mindprod.com/jgloss/preferences.html
-- 
Roedy Green Canadian Mind Products
The Java Glossary
http://mindprod.com

On Oct 26, 12:23 pm, Roedy Green <see_webs...@mindprod.com.invalid>
wrote:
> On Thu, 25 Oct 2007 03:07:24 -0700, Dexter <yousaf.a...@gmail.com>
> wrote, quoted or indirectly quoted someone who said :
>
> >How can I make the Java app work for a limited time. Say for a month
>
> seehttp://mindprod.com/jgloss/installer.html
>
> A very simple scheme just pokes the install date into the registry
> using the Preferences mechanism.
>
> Seehttp://mindprod.com/jgloss/preferences.html
> --
> Roedy Green Canadian Mind Products
> The Java Glossaryhttp://mindprod.com

Thanks Roedy, thats exactly what I needed

Regards

Asad

On Nov 1, 12:47 pm, Dexter <yousaf.a...@gmail.com> wrote:> On Oct 26, 12:23 pm, Roedy Green <see_webs...@mindprod.com.invalid>> wrote:> > A very simple scheme just pokes the install date into the registry> > using the Preferences mechanism.>> > Seehttp://mindprod.com/jgloss/preferences.html> Thanks Roedy, thats exactly what I neededThat's hackable in less than five minutes. I wouldn't consider itworth the lines of code needed to implement such a "protection".

Hunter Gratzner wrote:> On Nov 1, 12:47 pm, Dexter <yousaf.a...@gmail.com> wrote:>> On Oct 26, 12:23 pm, Roedy Green <see_webs...@mindprod.com.invalid>>> wrote:>>> A very simple scheme just pokes the install date into the registry>>> using the Preferences mechanism.>>> Seehttp://mindprod.com/jgloss/preferences.html> >> Thanks Roedy, thats exactly what I needed> > That's hackable in less than five minutes. I wouldn't consider it> worth the lines of code needed to implement such a "protection".> It may be useful for honest but forgetful users, by reminding them thatit is trialware and how long the trial has to run.Patricia

On Thu, 01 Nov 2007 14:14:58 -0000, Hunter Gratzner<a24900@googlemail.com> wrote, quoted or indirectly quoted someone whosaid :>That's hackable in less than five minutes.Depends on your audience. Your average user today could not evendelete or restore a file, much less probe the registry.Just a bit of camouflage for the key and value should do it for 99% ofyour users.-- Roedy Green Canadian Mind ProductsThe Java Glossaryhttp://mindprod.com

On Nov 1, 8:14 pm, Roedy Green <see_webs...@mindprod.com.invalid>wrote:> On Thu, 01 Nov 2007 14:14:58 -0000, Hunter Gratzner> <a24...@googlemail.com> wrote, quoted or indirectly quoted someone who> said :>> >That's hackable in less than five minutes.>> Depends on your audience. Your average user today could not even> delete or restore a file, much less probe the registry.>> Just a bit of camouflage for the key and value should do it for 99% of> your users.Why are you helping him to do something as evil and stupid as make hissoftware less useful and less valuable after going to all the work hehas to make it in the first place?

On Nov 2, 1:14 am, Roedy Green <see_webs...@mindprod.com.invalid>wrote:> Depends on your audience. Your average user today could not even> delete or restore a file, much less probe the registry.But your average user can operate a torrent client just fine.> Just a bit of camouflage for the key and value should do it for 99% of> your users.And all it takes is one of the remaining 1% to hack it and place it ona p2p network.

On Sat, 03 Nov 2007 10:20:02 -0000, Hunter Gratzner<a24900@googlemail.com> wrote, quoted or indirectly quoted someone whosaid :>And all it takes is one of the remaining 1% to hack it and place it on>a p2p network.If you are worried about a dedicated hacker cracking your code, youprobably should not even be distributing class files.See http://mindprod.com/jgloss/obfuscator.htmlFrequent updates with slight variations in obfuscation might be thebest defence, even if the updates are utterly trivial.  Your hackerwill  get bored recracking your code.  He is doing it for thechallenge.-- Roedy Green Canadian Mind ProductsThe Java Glossaryhttp://mindprod.com