Java web start and JRE versions

[Paul Robson]

A question regarding Java Web Start

I understand that by putting the appropriate link in the file I can force
download of a specified JRE to run the application (if it isn't already
there).

My question is ; does this overwrite the system JRE.

If I want to have JRE1.4 installed, but have an app that downloads JRE1.5
to run something via JWS, will the system be upgraded to 1.5 as well ?

Or does it depend on the OS ?

 

[Andrew Thompson]

A question regarding Java Web Start

I understand that by putting the appropriate link in the file I can force
download of a specified JRE to run the application (if it isn't already
there).

Your understanding is flawed. By putting the appropriate
*attribute* of the J2SE element of the JNLP, you can
specify either a minimum or exact version that needs
to be present for the app. to run.

By adding a location of the autodownload CAB, you can
also suggest to your end user, where they can get it,
and also show a generic download page for the non
IE/Windows users.

It is up to the end user whether they proceed with
the download, and their sytem administrator as to
whether they have the necessary rights to install it.

My question is ; does this overwrite the system JRE.
No.

If I want to have JRE1.4 installed, but have an app that downloads JRE1.5
to run something via JWS, will the system be upgraded to 1.5 as well ?

Probably, but then, that is probably a good thing to do
(upgrade) for any application that has not, itself, requested
version '1.4.oIFailOnAnyOtherMicroVersionJRE'.

Or does it depend on the OS ?

Shrugs.. Why worry about it?
Other applications or not our problem.

Andrew T.

 

[Paul Robson]

Thanks