How to Display Alerts evenwhen application is not running

Question

hi freinds
i want to tell the user that some data has gone into a
particular table through a back end procedure
(process/job) ..through an alert on the screen.
this has to be done in each of the client machine
or (those selected) even when the application is not running in
the machine,
can we use any scheduler or any such things in the server.
Please do let me know
Syam
null

Answer 1

Communication through files tends to fail if the
program exits abnormally and leaves the file in a
"running" state.If you store the pid the only way it fails is if the
program exits abnormally and then another process
starts up using the same pid as is stored in the file
before you restart your application. Basically it is
not likely to happen and if it does you just drop the
pid file.The point is that Java programs can't, generally, handle signals. That's what the commons Daemon stuff provides.
The standard way of stopping a unix background task is to use the stored pid to throw a "kill" at the process, whiich the process intercepts and does what you asked, e.g. close down tidily or reread it's configuration.
Java knows nothing about process ids.